My
Dear
Lord
,
SInce
I
have
already
in
proper
places
of
the
Physico-Mechanical
Experiments
about
the
Air
,
which
I
formerly
presented
your
Lordship
,
giv'n
you
a
sufficient
account
of
several
things
touching
the
Scope
,
Occasion
,
&c.
of
my
Attempt
;
it
will
not
be
necessary
to
make
a
solemn
Preface
to
the
ensuing
Experiments
.
And
therefore
presuming
upon
an
acceptance
,
which
the
favourable
Entertainment
,
which
your
Lordship
,
as
well
as
the
Publick
,
was
pleas'd
to
give
my
first
Tryals
of
this
kind
,
encourages
me
to
expect
,
I
shall
,
without
troubling
you
with
any
further
Preface
,
immediately
fall
upon
a
Continuation
;
especially
since
Your
Lordship
will
perhaps
wonder
,
that
you
have
not
receiv'd
it
much
sooner
,
as
,
indeed
,
you
should
have
done
,
if
I
had
been
befriended
with
Accommodations
and
Leisure
.
EXPERIMENT
I.
About
the
raising
of
Mercury
to
a
great
height
in
an
open
Tube
,
by
the
spring
of
a
little
included
Air.
DIvers
ways
have
been
proposed
to
shew
both
the
Pressure
of
the
Air
,
as
the
Atmosphere
is
a
heavy
Body
,
and
that
the
Air
,
especially
when
compress'd
by
outward
force
,
has
a
Spring
that
enables
it
to
sustain
or
resist
a
pressure
equal
to
that
of
as
much
of
the
Atmosphere
,
as
can
come
to
bear
against
it
,
and
also
to
shew
,
that
such
Air
as
we
live
in
,
and
is
not
condens'd
by
any
humane
or
adventitious
force
,
has
not
onely
a
resisting
Spring
,
but
an
active
Spring
(
if
I
may
so
speak
)
in
some
measure
,
as
when
it
distends
a
flaccid
or
breaks
a
full-blown
Bladder
in
our
exhausted
Receiver
.
But
observing
that
there
seems
to
want
a
visible
Experiment
to
convince
those
that
are
not
so
easily
satisfy'd
with
Reasons
,
though
drawn
by
just
consequence
from
Physical
or
Mechanical
Truths
,
or
even
from
other
Experiments
,
taking
notice
,
I
say
,
hereof
,
I
made
the
following
Experiments
;
not
so
much
to
prevent
or
removed
a
scruple
no
better
grounded
,
as
to
have
a
new
way
of
making
an
Estimate
by
some
known
and
determinate
measure
of
the
force
of
the
bare
Spring
of
the
Air
,
both
in
its
natural
state
,
(
as
t
is
said
to
be
when
not
compress'd
nor
ratify'd
,
more
then
the
free
Air
we
breath
,
)
and
according
to
its
several
degrees
of
Expansion
.
We
took
then
a
Viol
,
with
a
neck
not
very
large
,
and
having
fill'd
about
a
fourth
part
of
it
with
Quick-silver
,
we
so
erected
and
fastned
a
long
and
slender
Pipe
of
Glass
,
open
at
both
ends
in
the
neck
of
the
Viol
,
with
hard
sealing
wax
,
that
the
lower
end
reach'd
almost
to
the
bottom
of
the
Quick-silver
,
and
the
upper
more
then
a
yard
above
the
viol
.
Then
having
blown
in
a
little
air
,
to
try
whether
the
Instrument
did
not
leak
,
(
which
t
is
very
difficult
to
keep
such
instruments
from
doing
,
)
we
conveigh'd
it
into
a
long
and
slender
Receiver
,
For
the
better
illustration
of
this
Experiment
,
thus
summarily
related
,
but
with
the
like
success
,
as
to
the
main
,
several
times
repeated
,
we
will
subjoyn
the
following
Observations
and
Notes
.
I.
That
we
try'd
this
Experiment
several
times
,
and
the
last
time
in
the
presence
of
the
famous
Savilian
Geometer
,
Dr
Wallis
,
who
saw
the
Quick-silver
in
the
Pipe
impell'd
up
to
27.
inches
,
being
one
himself
of
the
measurers
;
and
though
at
other
times
we
found
it
to
be
much
about
the
same
height
with
the
last
,
yet
once
it
seem'd
plainly
to
be
a
pretty
deal
higher
;
which
yet
we
specifi'd
not
,
because
a
mischance
took
off
the
mark
,
which
we
had
made
to
measure
the
height
by
.
II.
Having
once
,
to
try
the
stanchnesse
of
the
viol
,
blown
in
so
much
Air
,
(
without
taking
out
any
thing
as
we
use
to
do
in
the
like
case
)
that
the
Air
in
the
cavity
of
the
viol
rais'd
and
kept
the
Quicksilver
3.
inches
high
in
the
Pipe
,
when
we
went
on
with
the
rest
of
the
Experiment
,
according
to
the
way
above
describ'd
,
we
found
,
by
emptying
the
Receiver
of
air
,
that
we
were
able
to
raise
the
Quicksilver
in
the
Cane
30.
inches
,
or
somewhat
more
above
that
in
the
viol
.
III.
Sometimes
it
may
happen
,
that
the
Mercury
,
when
taken
very
soon
out
of
the
Receiver
,
will
not
appear
to
have
subsided
to
its
first
lownesse
,
which
perhaps
't
will
not
sink
to
in
some
while
after
:
which
is
not
to
be
wondred
at
,
since
in
such
a
Receiver
,
which
contains
but
little
air
,
the
heat
of
the
Cement
and
the
iron
,
imploy'd
to
melt
it
quite
round
the
Receiver
,
may
impart
a
little
warmth
to
the
air
in
the
viol
,
which
will
after
return
to
its
former
Temper
.
But
this
Accident
is
neither
constant
nor
necessary
to
the
Experiment
.
IV.
T
is
very
remarkable
,
that
if
the
Receiver
be
fitly
stopt
,
and
slender
enough
;
upon
the
turning
of
the
Stop-cock
,
to
let
out
the
air
at
the
first
exuction
,
the
Mercury
will
be
impell'd
up
by
the
spring
of
the
Air
in
the
viol
,
suddenly
flying
abroad
or
stretching
it self
,
so
that
it
will
be
rais'd
several
inches
above
the
height
it
will
rest
at
afterwards
,
and
will
make
several
vibrations
up
and
down
before
it
come
to
settle
,
just
as
the
Mercury
does
in
the
Torricellian
Experiment
,
(
the
bare
pressure
of
the
little
air
doing
here
to
the
Mercury
,
what
the
weight
of
the
Atmosphere
does
there
,
)
and
such
motions
of
the
Mercury
will
be
made
four
or
five
subsequent
Exuctions
,
upon
the
withdrawing
of
the
air
in
the
Receiver
.
But
as
these
grow
lesser
and
lesser
,
as
the
Spring
of
the
included
Air
grows
fainter
,
so
none
of
them
is
any
thing
near
so
considerable
as
the
vibrations
made
upon
the
first
Suck
.
V.
Agreeable
hereunto
we
observ'd
,
that
at
the
first
Exuction
,
when
the
Spring
of
the
included
Air
was
yet
strong
,
the
Mercury
would
be
rais'd
by
our
Estimate
above
half
,
if
not
⅔
of
the
whole
height
,
whereto
't
will
at
length
be
brought
,
(
though
that
must
be
according
to
the
bignes
of
the
Receiver
,
and
other
circumstances
,
)
and
the
subsequent
Exuctions
do
still
adde
less
and
less
proportions
of
height
to
the
Mercurial
Cylinder
,
and
that
for
two
Reasons
:
the
one
,
because
the
more
there
is
of
Mercury
impell'd
into
the
Tube
,
the
greater
weight
of
Mercury
presses
upon
the
included
air
:
and
the
other
,
because
the
air
has
so
much
the
more
room
in
the
viol
to
expand
it self
,
whereby
its
spring
must
be
proportionably
weakned
.
Lastly
,
when
we
made
most
of
these
Tryals
,
I
had
the
curiosity
to
observe
the
height
of
the
Mercury
in
a
good
Barometer
,
and
thereby
found
,
that
the
Air
was
then
but
light
;
its
greatest
height
reaching
but
to
29
inches
,
and
⅜
,
and
its
height
soon
after
the
Tryal
,
whereof
Dr
Wallis
was
a
witnesse
,
amounting
but
to
29.
inches
.
To
make
an
estimate
of
the
Quantity
of
Air
,
that
had
rais'd
the
Quicksilver
to
27
inches
,
we
took
the
viol
that
was
imploy'd
about
this
Experiment
;
and
having
counterpois'd
it
,
whilst
it
was
empty
,
we
afterward
fill'd
it
with
water
,
and
found
the
Liquor
to
weigh
5.
Ounces
,
2.
Drachms
,
and
about
20.
Grains
;
and
then
having
pour'd
out
the
water
,
till
it
was
sunk
to
a
mark
which
we
had
made
on
the
outside
of
the
Glass
,
to
take
notice
how
high
the
Quick-silver
reach'd
that
we
pour'd
in
:
and
lastly
,
weighing
the
remaining
water
,
equal
in
bulk
to
the
Quick-silver
,
we
found
it
to
amount
to
1.
Ounce
,
2.
Drachms
,
14.
Grains
;
so
that
the
air
,
that
had
rais'd
up
the
Mercury
,
possess'd
(
before
its
Expansion
)
in
the
viol
the
place
but
of
4.
ounces
,
and
a
few
odde
grains
,
i.
e.
of
about
¼
of
a
Pint
of
water
.
And
as
for
the
Pipe
also
,
imploy'd
about
the
same
Experiment
,
we
found
its
Cavity
to
have
about
⅛
part
of
an
Inch
in
Diameter
.
It
was
one
of
the
Uses
I
hop'd
to
make
of
this
Experiment
,
that
by
comparing
the
several
degrees
of
Expansion
of
air
included
in
the
viol
,
with
the
respective
and
increasing
heights
of
the
Mercury
that
was
impell'd
up
into
the
Pipe
,
some
estimate
might
be
made
of
the
force
of
the
Spring
of
the
Air
weaken'd
by
several
degrees
of
Dilatation
;
but
for
want
of
conveniences
I
forbore
to
venter
upon
such
nice
Observations
,
especially
because
the
Pressure
of
the
dilated
air
,
that
remains
in
the
Receiver
,
and
is
external
to
the
air
included
in
the
viol
,
must
also
be
taken
into
consideration
.
Another
Use
of
our
Experiment
may
be
this
:
That
it
may
supply
us
with
a
considerable
Argument
against
some
Learned
men
,
who
attribute
the
suspension
of
the
Quick-silver
in
the
Torricellian
Experiment
to
a
certain
rarify'd
matter
,
which
some
call
a
Funiculus
,
and
whereto
others
give
other
names
;
which
rarify'd
substance
they
suppose
to
draw
up
and
sustain
the
Quick-silver
,
in
compliance
of
Natures
abhorrency
of
a
Vacuum
.
For
in
the
Experiment
under
consideration
,
the
Quick-silver
being
not
onely
sustain'd
at
the
height
of
27
inches
in
the
Tube
,
but
elevated
thither
;
if
the
cause
of
This
be
demanded
,
it
will
be
answer'd
,
according
to
their
hypothesis
,
that
the
air
in
the
Receiver
,
external
to
that
of
the
Viol
,
being
,
by
reason
of
the
sucking
out
of
some
of
it
by
the
Pump
,
more
rarified
than
that
in
the
viol
,
it
draws
up
to
it
the
Quick-silver
in
the
Cane
,
and
the
more
it
is
rarify'd
,
the
higher
it
is
enabl'd
to
draw
it
.
But
then
I
demand
,
whence
it
comes
to
pass
,
that
though
we
can
,
by
persevering
to
pump
,
more
and
more
rarifie
the
little
remaining
air
,
or
the
Aëreal
substance
in
the
Receiver
,
That
in
the
viol
not
appearing
to
be
also
rarified
,
yet
the
air
in
the
Receiver
does
not
by
virtue
of
its
superadded
rarefaction
,
whereby
it
exceeds
that
of
the
air
in
the
viol
,
pull
up
the
Quick-silver
to
a
greater
height
in
the
Tube
then
27.
inches
:
For
,
that
this
is
not
the
greatest
height
,
to
which
Mercury
may
be
rais'd
by
this
rarefy'd
substance
,
our
Adversaries
must
not
deny
,
who
tell
us
,
that
in
the
Torricellian
Experiment
it
sustains
a
Mercurial
Cylinder
of
29.
inches
,
and
½
,
and
can
raise
a
Cylinder
of
29
inches
to
29
½
,
or
higher
,
in
case
that
the
Cylinder
be
made
to
vibrate
up
and
down
in
the
Tube
.
And
as
for
those
,
EXPERIMENT
II.
Shewing
,
that
much
included
Air
rais'd
Mercury
in
an
open
Tube
,
no
higher
than
the
weight
of
the
Atmosphere
may
in
a
Baroscope
.
IN
the
former
Experiment
,
by
reason
of
the
smalness
of
the
viol
,
that
was
employ'd
about
it
,
there
was
so
little
Air
included
,
that
the
Expansion
of
it
so
far
,
as
was
requisite
to
impell
up
the
Mercury
in
the
Pipe
to
the
above
mentioned
height
of
27.
inches
,
may
be
probably
suspected
to
have
very
much
weaken'd
its
Spring
,
and
therefore
it
may
be
thought
,
that
(
especially
considering
the
great
force
that
several
of
our
Experiments
manifest
imprison'd
air
to
have
,
)
if
there
were
a
greater
Quantity
of
air
included
in
the
vessel
,
so
that
the
Expansion
,
sufficient
to
raise
the
Mercury
to
the
former
height
,
would
not
need
to
be
considerable
,
(
because
that
the
capacity
of
the
Tube
being
but
the
same
,
the
whole
included
air
will
be
so
much
the
lesse
expanded
,
by
how
much
the
more
of
it
there
is
,
)
it
seem'd
probable
that
the
Spring
of
the
Air
,
being
but
a
little
weakned
by
so
small
a
dilatation
,
would
remain
strong
enough
to
raise
a
much
taller
Cylinder
of
Mercury
in
the
Tube
,
and
perhaps
make
the
Liquor
run
over
into
the
Receiver
.
But
though
this
Suggestion
seem
probable
enough
,
yet
when
I
consider'd
,
that
the
weight
of
the
Atmosphere
is
able
to
sustain
a
Cylinder
of
Quick-silver
but
of
30.
inches
,
or
thereabouts
,
(
in
perpendicular
height
,
)
and
consequently
that
the
pressure
of
such
a
Mercurial
Cylinder
is
equivalent
to
that
of
an
Atmospherical
Cylinder
of
the
same
bore
;
't
was
not
difficult
to
conclude
,
that
since
the
Air
in
a
viol
,
before
the
mouth
is
clos'd
,
has
a
Spring
but
equal
in
strength
to
the
weight
of
the
Atmospherical
Pillar
that
leans
upon
it
,
(
for
if
the
Spring
were
too
strong
for
the
weight
that
leans
on
it
,
some
of
the
air
would
get
out
of
the
viol
,
)
a
greater
viol
,
and
consequently
a
greater
quantity
of
included
air
would
not
be
able
by
its
spring
to
elevate
and
sustain
a
longer
Cylinder
of
Mercury
,
than
the
weight
of
the
Atmosphere
is
able
to
do
;
nor
indeed
altogether
so
much
,
because
of
some
little
(
though
but
little
)
Diminution
of
the
Spring
by
some
(
though
but
a
small
)
expansion
,
that
the
included
Air
suffers
,
by
succeeding
in
the
place
of
the
Mercury
,
that
is
impell'd
up
.
To
clear
therefore
this
matter
by
an
Experiment
,
we
took
a
strong
glass-bottle
,
capable
of
holding
about
a
Quart
of
Liquor
,
and
having
put
into
it
a
convenient
quantity
of
Quick-silver
,
we
erected
in
it
a
very
long
and
slender
pipe
of
Glass
,
open
at
both
the
ends
,
and
reaching
at
the
lower
end
beneath
the
surface
of
the
stagnant
Mercury
,
and
having
fasten'd
this
pipe
in
the
neck
of
the
Bottle
,
by
choaking
up
that
neck
very
accurately
with
good
Cement
,
that
none
of
the
included
air
might
be
able
to
get
out
,
we
conveigh'd
the
whole
into
a
Receiver
,
like
that
imploy'd
about
the
I.
Experiment
in
shape
,
but
much
larger
,
that
it
might
be
able
to
contain
so
great
a
vessel
;
and
then
the
Engine
being
set
a
work
,
we
quickly
rais'd
the
Quick-silver
to
a
greater
height
than
formerly
,
and
when
we
saw
it
come
to
a
stand
,
we
did
by
the
help
of
some
marks
,
made
before
hand
on
the
pipe
,
and
by
the
help
of
a
very
long
and
well
divided
Ruler
,
measure
,
with
as
much
care
and
accurateness
as
the
figure
of
the
vessels
would
allow
us
to
do
,
the
height
of
the
Mercurial
Cylinder
,
which
we
found
to
be
29.
inches
,
and
about
⅞
,
to
which
abating
half
an
inch
,
which
was
rais'd
,
before
the
Pump
was
employed
,
by
some
air
that
had
been
blow'd
into
the
Bottle
,
to
try
whether
it
were
stanch
;
deducting
,
I
say
,
this
half
Inch
of
Quick-silver
,
which
remain'd
in
the
Tube
after
the
external
Air
was
let
in
,
(
as
well
as
it
had
been
there
before
the
Receiver
was
exhausted
,
)
out
of
the
newly
mention'd
number
there
remain'd
29.
inches
,
and
neer
⅜
,
for
the
height
of
the
Mercury
,
rais'd
by
the
Spring
of
the
Air
,
shut
up
in
the
Bottle
:
and
then
consulting
with
the
above
mentioned
Baroscope
,
which
stood
in
a
window
in
another
part
of
the
house
,
I
found
,
that
the
weight
of
the
Atmosphere
did
bear
a
Mercurial
Cylinder
of
about
29.
Inches
and
½
,
which
was
higher
by
⅛
than
that
to
which
the
Spring
had
rais'd
the
Quick-silver
in
the
exhausted
Receiver
:
and
the
Difference
perhaps
would
have
been
greater
,
if
the
place
,
where
the
Experiment
was
made
,
had
not
by
its
warmth
added
some
little
matter
to
the
Spring
of
the
Air
,
and
if
also
we
could
have
kept
the
Mercury
so
long
elevated
,
as
to
give
it
leave
to
discharge
its
self
of
those
small
bubbles
,
which
t
is
almost
impossible
in
such
Experiments
as
this
to
free
Quick-silver
from
,
without
some
help
from
time
.
Lastly
,
though
we
caus'd
the
Pump
to
be
ply'd
,
to
try
whether
we
could
not
,
by
the
more
diligent
Exuction
of
the
Receiver
,
raise
the
Quick-silver
above
the
height
of
that
which
the
Atmosphere
kept
sustain'd
in
the
Baroscope
,
yet
our
labour
gave
us
but
a
confirmation
,
that
the
Spring
of
the
Air
would
not
raise
the
Mercury
higher
,
then
did
the
weight
of
the
Atmosphere
,
which
may
not
a
little
confirm
the
2d
Observation
.
N
B.
This
was
not
the
onely
nor
the
first
Experiment
we
made
of
this
kind
,
but
this
being
carried
on
without
mischances
,
(
with
which
divers
others
were
attended
,
)
and
made
with
much
care
,
I
thought
fit
to
set
down
This
in
stead
of
all
,
intimating
generally
about
the
rest
,
that
they
seem'd
to
agree
well
for
the
main
with
that
,
which
is
here
recited
;
onely
there
is
one
thing
relating
to
those
other
Experiments
,
that
seems
not
altogether
unworthy
to
be
taken
notice
of
;
which
is
,
that
when
our
Tryals
were
made
in
vessels
,
that
contain'd
a
considerable
quantity
of
Air
,
though
upon
the
exhaustion
of
the
Receiver
the
Spring
of
the
included
Air
could
not
raise
the
Quick-silver
to
the
top
of
the
pipe
,
yet
sometimes
by
other
Effects
it
manifested
it self
to
be
very
strong
,
as
once
or
twice
by
the
blowing
out
or
breaking
the
Cork
or
Cement
,
and
other
matter
that
was
imploy'd
to
stop
the
Glass
it
was
shut
in
;
and
once
by
an
Accident
too
memorable
to
be
here
past
over
in
silence
.
I
had
one
day
invited
Dr
Wallis
to
see
such
an
Experiment
as
I
have
been
relating
,
made
with
(
not
a
viol
,
but
)
a
bottle
of
Green
Glass
,
(
such
as
we
use
now
for
Wine
,
)
and
4
or
5
pounds
of
Mercury
.
After
this
Learned
Person
and
I
had
continued
Spectators
as
long
as
we
thought
fit
,
we
withdrew
into
another
Room
,
where
we
had
not
sat
long
by
the
fire
,
before
we
were
surpriz'd
by
a
suddain
noise
,
which
the
person
,
that
occasion'd
it
,
presently
came
running
in
to
give
us
an
account
of
,
by
which
it
appear'd
,
that
this
Ingenious
young
Man
,
(
whom
I
often
imploy
about
Pneumatical
Experiments
,
and
whom
I
mention'd
to
Your
Lordship
,
because
I.
M.
has
the
honour
to
be
somewhat
known
to
You
,
)
being
desirous
in
our
absence
to
satisfie
the
Curiosity
he
had
to
know
,
whether
the
Quick-silver
could
not
be
rais'd
higher
in
the
pipe
than
I
had
foretold
,
plyed
the
Pump
so
obstinately
,
that
at
length
,
the
Bottle
being
not
,
it
seems
,
every
where
equally
strong
,
the
imprison'd
air
found
it
more
difficult
to
make
the
Quick-silver
run
over
at
the
top
of
the
pipe
,
than
to
break
the
Bottle
in
the
weakest
place
,
and
accordingly
did
not
onely
throw
off
a
piece
of
the
Bottle
,
but
threw
it
with
such
violence
against
the
large
and
strong
Receiver
,
as
broke
that
also
,
and
render'd
it
unserviceable
for
the
future
.
But
the
Doctor
and
I
laying
together
the
Pipe
,
which
happen'd
to
be
broken
into
but
few
pieces
,
concluded
by
the
place
,
to
which
we
were
told
it
reacht
when
this
Accident
happened
,
that
it
had
not
exceeded
,
nor
indeed
fully
equall'd
the
height
,
to
which
the
weight
of
the
Atmosphere
might
have
rais'd
it
.
EXPERIMENT
III.
Shewing
that
the
Spring
of
the
included
Air
will
raise
Mercury
to
almost
equal-heights
in
very
unequal
Tubes
.
HAving
shown
in
the
two
former
Experiments
,
that
the
Active
strength
of
the
Airs
Spring
is
very
considerable
,
I
thought
good
also
to
examine
,
whether
or
no
to
the
other
resemblances
in
operation
between
the
weight
of
the
free
Air
,
and
the
pressure
of
the
included
Air
,
this
also
may
be
added
,
that
as
the
gravitation
of
the
Atmosphere
is
able
(
as
we
shall
hereafter
prove
)
to
sustain
the
Mercury
at
the
same
height
in
lesser
and
greater
Tubes
,
seal'd
at
the
top
;
so
the
Pressure
of
the
included
Air
may
be
able
to
sustain
the
Mercury
at
the
same
height
in
slenderer
and
in
larger
Tubes
,
though
in
the
latter
it
must
sustain
a
far
greater
weight
of
Mercury
than
in
the
former
;
provided
allowance
be
made
for
the
weakning
,
which
the
Spring
of
the
included
Air
must
be
subject
to
,
by
reason
that
,
to
succeed
in
the
place
of
a
large
Cylinder
of
Mercury
impell'd
up
into
the
greater
Tube
,
it
must
expand
it self
more
,
and
consequently
have
its
Spring
more
weakned
,
than
if
the
Tube
were
slender
.
To
prosecute
this
Experiment
,
I
thought
on
a
peculiar
shape
of
vessels
,
which
,
if
I
had
been
where
there
is
a
Glass-house
,
I
would
have
caus'd
to
be
blown
for
the
more
convenient
trying
of
two
Pipes
of
different
bores
at
the
same
time
.
But
though
I
wanted
this
Accommodation
,
I
thought
I
might
well
enough
show
what
I
intended
by
imploying
successively
two
Tubes
of
very
differing
sizes
,
provided
the
vessel
for
the
including
of
the
Air
were
the
same
.
Wherefore
taking
the
Glass
bottle
,
made
use
of
to
try
the
former
Experiment
,
and
erecting
in
it
after
the
manner
above
described
a
Cylindrical
pipe
of
Glass
,
a
good
deal
larger
than
the
former
,
(
if
not
as
large
agen
,
)
we
prosecuted
the
Experiment
as
we
had
made
it
,
with
the
slender
Tube
above
mentioned
,
and
found
that
we
were
able
,
by
the
Spring
of
the
Air
in
the
bottle
,
to
raise
the
Quick-silver
to
a
considerable
height
,
which
,
measuring
as
well
as
the
vessel
would
allow
us
,
was
,
by
the
least
estimate
that
was
made
of
it
,
(
which
was
mine
)
28.
inches
,
and
⅛
,
by
which
it
appear'd
to
want
somewhat
above
an
Inch
of
the
height
of
the
Mercurial
Cylinder
,
which
the
weight
of
the
Atmosphere
could
have
sustain'd
,
as
appear'd
by
the
Barometer
,
wherein
the
Quick-silver
at
that
time
was
about
29.
inches
,
and
¼
high
;
which
difference
was
no
more
then
I
expected
,
considering
that
,
whereas
the
weight
of
the
Atmosphere
is
still
the
same
when
the
Mercury
is
at
its
full
height
(
and
that
whether
the
Pipe
be
great
or
small
)
in
a
seal'd
Tube
;
the
Spring
of
our
included
Air
must
needs
be
weakned
the
larger
the
Tube
is
,
and
the
higher
the
liquid
Metal
is
impell'd
in
it
,
so
that
it
seem'd
a
considerable
Phaenomenon
,
that
the
Spring
of
so
little
Air
should
be
able
to
raise
the
Mercury
as
high
within
an
Inch
or
thereabouts
in
a
wider
as
in
a
slenderer
Tube
,
since
the
Diameter
of
the
Cavity
of
the
former
being
by
our
estimate
double
to
that
of
the
latter
,
(
into
which
the
slender
Pipe
could
easily
be
put
as
into
a
Case
too
big
for
it
:
)
The
greater
Mercurial
Cylinder
may
be
suppos'd
to
have
weighed
near
four
times
as
much
as
the
lesser
;
I
say
,
near
,
because
there
was
an
Inch
difference
in
their
heights
:
but
in
case
these
had
been
equal
,
then
the
Solidities
of
the
Cylinders
would
have
been
to
one
another
as
their
Bases
;
and
since
these
,
being
Circular
,
are
in
duplicate
proportion
to
their
Diameters
,
that
is
,
as
the
Squares
of
their
Diameters
;
its
plain
,
that
if
the
Diameters
be
as
one
to
two
,
the
Squares
of
them
must
be
as
one
to
four
;
and
these
Cylinders
consisting
of
the
same
Mercury
,
their
Weights
will
have
the
same
Proportions
with
their
Solidities
,
and
consequently
would
be
as
one
to
four
,
making
the
abatement
formerly
intimated
for
the
Inch
and
a
little
more
of
Mercury
,
by
which
the
larger
Cylinder
came
short
of
the
height
of
the
former
.
NB.
1.
This
and
the
two
former
Experiments
tryed
by
us
with
Quick-silver
,
may
be
also
tryed
with
Water
;
but
besides
that
we
could
hardly
procure
Tubes
long
enough
for
such
Tryals
,
we
were
not
very
sollicitous
about
it
:
for
if
we
attentively
enough
consider
,
what
has
been
already
deliver'd
,
and
the
Proportion
in
specifick
gravity
betwixt
Water
and
Quick-silver
,
(
whereof
the
latter
is
near
14.
times
as
heavy
,
bulk
for
bulk
,
as
the
former
,
)
't
will
not
be
difficult
to
foresee
the
Event
of
such
Experiments
,
which
he
,
that
has
a
mind
to
make
,
should
be
furnish'd
not
onely
with
long
Tubes
,
but
with
capacious
Vessels
to
shut
up
the
Air
in
.
Else
the
Air
will
be
so
far
expanded
before
the
Water
has
attain'd
near
the
height
,
to
which
the
weight
of
the
Atmosphere
may
raise
it
,
that
the
Experiments
will
not
seem
to
succeed
near
so
well
with
Water
,
as
ours
did
with
Quick-silver
.
2.
We
thought
it
worth
trying
,
whether
,
when
the
included
Air
had
rais'd
the
great
Cylinder
of
Mercury
to
the
utmost
height
,
it
could
elevate
it
to
,
by
the
Spring
it
then
had
;
it
would
not
be
brought
to
raise
the
Quick-silver
yet
higher
,
if
,
notwithstanding
the
Expansion
it
had
already
,
there
were
an
agitation
made
by
the
heated
Corpuscles
of
the
same
Air.
And
in
pursuance
of
this
Curiosity
having
caus'd
an
hot
Iron
and
a
Shovel
of
kindled
Coals
to
be
held
near
the
opposite
parts
of
the
Receiver
,
we
perceiv'd
after
a
while
,
that
the
Mercury
ascended
⅛
of
an
inch
or
better
above
the
greatest
height
it
had
reach'd
before
.
But
conjecturing
that
it
would
have
risen
higher
,
were
it
not
that
whilst
the
application
of
the
hot
bodies
was
making
,
some
Particles
of
Air
had
unperceivably
stolen
into
the
Receiver
,
I
caus'd
the
Pump
to
be
ply'd
again
to
withdraw
the
Air
,
I
suspected
to
have
got
in
,
by
which
means
the
Mercury
was
quickly
rais'd
⅝
of
an
inch
,
(
or
better
,
)
by
virtue
of
this
Adventitious
Spring
,
(
if
I
may
so
call
it
,
)
which
the
included
Air
acquir'd
by
heat
,
and
I
made
no
doubt
,
that
it
might
have
been
rais'd
much
higher
,
but
I
was
unwilling
by
applying
a
less
moderate
heat
to
hazard
the
breaking
of
my
Glasses
,
in
the
place
I
then
was
in
,
where
such
a
mischance
could
scarce
have
been
repair'd
.
EXPERIMENT
IV.
About
a
new
Hydraulo-pneumatical
Fountain
,
made
by
the
Spring
of
uncompress'd
Air.
I
Shall
now
add
such
an
application
of
the
Principle
whereon
the
former
Experiment
was
grounded
,
as
I
should
scarce
think
worth
mentioning
in
this
place
,
were
it
not
that
besides
that
divers
Virtuosi
seem
not
a
little
delighted
with
it
,
it
may
for
ought
I
know
prove
to
be
of
some
Philosophical
use
(
to
be
pointed
at
hereafter
.
)
We
took
a
Glass-bottle
with
a
convenient
quantity
of
Water
in
it
,
and
fitted
this
Bottle
with
a
slender
glass-pipe
open
at
both
ends
,
and
about
three
foot
long
,
which
was
so
plac'd
,
that
the
lower
Orifice
was
a
good
way
beneath
the
Surface
of
the
Water
,
and
the
Pipe
it self
passed
perpendicularly
upwards
through
the
Neck
of
the
Bottle
,
which
Neck
was
,
by
the
Pipe
and
by
good
hard
Cement
imploy'd
to
fill
the
space
betwixt
the
Pipe
and
the
inside
,
so
well
and
firmly
clos'd
,
that
no
Water
or
Air
could
get
out
of
the
bottle
,
This
double
Receiver
being
cemented
on
to
the
Engine
,
a
little
of
the
Air
was
by
one
Suck
of
the
Pump
drawn
out
from
it
,
by
which
the
Pressure
of
the
remaining
Air
being
weakned
,
it
was
necessary
,
that
since
the
Air
included
in
the
Bottle
had
not
its
Spring
likewise
weakned
,
it
should
expand
it self
,
and
consequently
impell
up
the
water
in
the
same
Bottle
through
the
Pipe
,
which
it
did
so
vigorously
,
as
to
make
it
strike
briskly
at
first
against
that
part
of
the
top
of
the
smaller
Receiver
,
which
was
just
over
the
Orifice
of
the
Pipe
.
But
after
it
had
a
while
made
the
Water
thus
shoot
up
in
a
perpendicular
line
,
as
the
Spring
of
the
Air
in
the
Bottle
grew
by
that
Airs
dilatation
to
be
weaken'd
,
the
Water
would
be
impell'd
up
less
strongly
and
less
directly
,
till
the
Air
in
the
Bottle
being
as
much
expanded
as
that
in
the
Receiver
,
the
Ascent
of
the
Water
would
quite
cease
,
unless
by
Pumping
a
little
more
Aire
out
of
the
Receiver
we
renew'd
it
again
.
About
the
making
of
this
Experiment
these
Particulars
may
be
noted
.
1.
T
is
convenient
,
that
the
upper
part
of
the
Pipe
be
made
(
as
it
easily
may
be
at
the
flame
of
a
Lamp
)
very
slender
,
that
the
Water
having
but
a
very
small
Orifice
to
issue
out
at
,
may
be
spent
but
slowly
,
and
thereby
make
the
Experiment
last
so
much
the
longer
.
2.
You
may
,
if
you
please
,
in
stead
of
making
the
upper
part
of
the
Pipe
slender
,
as
was
just
now
directed
,
Cement
on
to
it
a
Top
either
of
Glass
or
Brass
,
consisting
of
three
or
more
very
slender
Pipes
,
with
a
Pin-hole
at
the
end
of
each
,
that
one
of
these
pointing
directly
upwards
,
and
the
others
to
the
right
hand
and
to
the
left
,
the
Water
may
spin
out
several
ways
at
once
,
by
which
kind
of
branched
Pipes
we
have
sometimes
imitated
the
Jets
d'
eau
(
as
the
French
call
them
)
and
Artificial
fountains
of
Gardens
and
Groto's
.
3.
In
regard
that
so
short
a
Cylinder
of
Water
,
as
exceeded
not
the
length
of
our
Glass
pipe
,
could
not
make
any
considerable
resistance
to
the
expansion
of
the
included
Air
,
it
was
thought
and
found
safe
enough
to
imploy
in
stead
of
a
strong
Glass-bottle
a
much
larger
Viol
,
without
being
sollicitous
about
its
shape
,
or
that
it
should
be
very
strong
,
and
by
this
means
we
could
make
this
pleasant
Spectacle
last
a
great
while
,
especially
if
we
also
made
use
of
the
expedient
to
be
mentioned
in
the
following
Note
.
4.
If
you
find
that
the
included
Air
have
by
expanding
it self
too
much
weaken'd
its
Spring
,
whilst
there
yet
remains
with
it
a
good
quantity
of
Water
in
the
Bottle
or
Viol
,
you
may
reinforce
the
pressure
of
the
Air
by
onely
turning
the
Stop-cock
,
and
letting
in
what
air
you
think
fit
to
the
exhausted
Receiver
:
for
upon
the
admission
of
this
new
Air
,
the
Air
in
the
Receiver
will
press
sisted
on
?
If
as
a
Law-maker
,
then
even
the
Sanction
will
continue
,
by
which
such
Laws
as
these
obliged
formerly
:
So
they
will
still
oblige
as
Laws
,
whilst
the
same
reason
continues
for
which
God
was
at
first
pleas'd
to
impose
them
.
If
as
an
infallible
Judge
of
Reason
;
still
it
will
follow
,
that
whilst
the
Reason
holds
,
they
will
be
so
far
from
being
made
unlawful
in
such
Particulars
wherein
the
Reason
does
indeed
hold
,
that
their
performance
will
still
be
acceptable
to
God
,
tho'
not
commanded
by
him
.
Either
way
of
Explication
is
sufficient
to
overthrow
his
whole
way
of
reasoning
,
as
manag'd
by
our
Adversaries
.
But
what
if
we
should
turn
this
way
of
reasoning
us'd
by
the
Apostles
,
Instrumental
Musick
fit
for
Sacrifices
in
the
Apostles
days
make
it
fit
still
.
against
our
Adversaries
?
What
if
we
should
conclude
,
That
because
Instrumental
Musick
was
us'd
then
in
their
Temple
Sacrifices
,
therefore
it
should
still
be
at
least
fit
and
acceptable
in
our
present
Eucharistical
Sacrifices
?
I
cannot
foresee
what
they
could
say
,
why
we
should
not
have
reason'd
as
the
Apostles
did
;
or
how
the
Apostles
could
blame
us
for
doing
so
;
or
why
our
Adversaries
should
blame
us
;
who
profess
themselves
such
Enemies
of
Impositions
,
if
they
did
not
impose
upon
us
more
than
the
Apostles
,
in
so
easily
condemning
matters
of
this
nature
as
unlawful
.
They
can
pretend
no
more
condemnation
in
other
places
of
the
Writings
of
the
Apostles
in
this
Case
,
than
in
those
others
wherein
the
Apostles
themselves
allow
this
way
of
Arguing
.
And
I
know
no
reason
from
the
natures
of
the
things
themselves
,
that
even
our
Adversaries
can
pretend
to
be
temporary
,
or
that
will
not
make
Instrumental-Musick
as
suitable
to
our
present
Worship
,
as
it
was
to
that
of
the
Apostles
.
No
sort
of
Sacrifices
were
more
proper
for
Hymns
than
those
that
are
Eucharistical
,
and
such
all
ours
are
now
,
but
were
not
so
in
the
Days
of
the
Apostles
.
And
the
use
of
Hymns
neither
is
,
nor
can
be
denied
by
our
Adversaries
,
as
well
in
the
private
Synaxes
of
the
Apostolical
Christians
,
as
in
the
Worship
of
the
Temple
.
The
Hymn
to
Christ
as
a
God
in
Pliny
,
Pli.
l.
x.
Ep.
appeal'd
to
in
the
latter
end
of
the
second
Century
as
a
very
early
evidence
of
the
belief
of
his
Deity
,
seems
to
have
been
joined
with
the
Eucharist
.
For
Pliny
tells
us
,
on
the
same
occasion
,
of
the
Covenant
the
Christians
entred
into
against
all
the
liberties
us'd
by
wicked
Persons
.
And
the
publick
Singers
are
mention'd
in
the
earliest
distinct
Accounts
we
have
of
their
Offices
,
not
as
newly
introduc'd
,
but
as
actually
obtaining
without
any
memory
of
a
late
Original
.
Had
the
reasons
of
the
things
been
all
that
had
been
requisite
for
raising
of
the
Affections
,
I
cannot
conceive
any
need
our
Adversaries
can
pretend
for
Singing
:
That
does
no
otherways
contribute
to
the
raising
of
the
Affections
,
than
as
the
assistance
and
improvement
of
the
Imagination
may
be
supposed
to
contribute
to
it
.
The
Singing
does
not
add
a
new
Reason
,
nor
impose
the
old
ones
,
why
the
Affections
should
be
raised
.
But
however
,
they
do
dispose
the
Affections
to
follow
Reason
,
more
readily
and
more
vigorously
than
they
would
if
they
had
not
the
assistance
of
a
favourable
Imagination
:
And
that
by
the
Nature
of
the
Things
themselves
;
and
in
that
regard
,
Musick
Instrumental
,
also
was
acknowledg'd
to
have
the
same
influence
that
Singing
had
by
the
Imagination
over
the
Affections
;
and
to
add
to
the
advantages
of
Singing
Vocally
:
So
it
was
,
that
David's
playing
on
the
Harp
cured
Saul
of
the
evil
Spirit
,
by
curing
that
Melancholy
which
disposed
him
to
receive
the
Influences
of
the
Evil
Spirit
:
So
it
was
,
that
the
like
use
of
Instrumental
Musick
dispos'd
Elisha
for
the
influences
of
the
good
Spirit
,
by
composing
that
Passion
which
his
Zeal
against
the
Idolatry
of
the
King
of
Israel
had
put
the
Prophet
into
;
it
made
him
capable
of
being
acted
by
the
Spirit
of
Prophesy
:
For
chearfulness
of
Temper
is
one
of
the
Dispositions
requir'd
by
the
Rabinnical
Jews
themselves
,
for
fitting
Men
for
Prophecy
.
That
may
possibly
be
the
Reason
why
the
Scriptures
mention
Instrumental
Musick
as
receiv'd
in
the
Schools
of
the
Prophets
,
Divine
Spirit
.
The
Singing
Hymns
to
such
Instruments
is
call'd
Prophesying
,
in
the
places
now
mention'd
.
So
far
the
nature
of
the
Spiritual
Worship
of
the
Gospel
,
is
from
superseding
this
assistance
of
Instrumental
Musick
,
as
our
Adversaries
would
have
us
believe
,
that
on
the
contrary
I
had
done
)
not
satisfied
about
them
.
Onely
He
sometimes
(
as
I
also
did
)
observ'd
the
Salient
water
to
describe
part
of
a
line
perfectly
enough
Parabolical
,
with
which
sort
of
Curves
he
has
been
particularly
conversant
.
This
made
me
resolve
for
further
satisfaction
to
attempt
by
another
contrivance
,
(
of
whose
success
,
if
I
can
procure
the
Implements
I
need
,
Your
Lordship
may
expect
an
account
,
)
what
the
Figures
will
be
not
onely
of
Salient
water
,
but
Mercury
,
and
other
Liquors
;
and
that
when
the
Receiver
is
much
better
exhausted
,
then
it
was
necessary
it
should
be
in
the
foregoing
Experiment
.
EXPERIMENT
V.
About
a
way
of
speedily
breaking
Flat
Glasses
,
by
the
weight
of
the
Atmosphere
.
FOr
the
more
easie
understanding
of
some
of
the
subsequent
Tryals
,
it
will
be
requisite
in
this
place
to
mention
among
Experiments
about
the
Spring
of
the
Air
the
following
Phaenomenon
belonging
to
its
Weight
.
This
is
one
of
those
that
is
the
most
usually
shown
to
Strangers
,
as
a
plain
and
easie
proof
both
that
the
Weight
of
the
incumbent
Air
is
considerable
,
and
that
the
round
figure
of
a
Receiver
doth
much
more
conduce
to
make
an
exhausted
Glass
support
that
weight
,
than
if
the
upper
part
of
the
Receiver
were
flat
.
To
make
this
Experiment
we
provided
a
Hoop
or
Ring
of
Brass
of
a
considerable
thickness
,
whose
height
was
2
½
,
or
3
Inches
,
and
the
Diameter
of
whose
Cavity
as
well
at
the
upper
as
lower
Orifice
(
should
have
been
just
3.
Inches
,
but
through
the
errour
of
the
workman
)
was
3.
inches
and
2/10.
To
this
Hoop
we
successively
fasten'd
with
Cement
divers
round
pieces
of
Glass
,
such
as
is
used
by
Glasiers
(
to
whose
Shops
we
sent
for
it
)
to
make
Panes
for
Windows
,
and
thereby
made
the
Brass-ring
with
its
Glass-cover
a
kind
of
Receiver
,
whose
open
Orifice
we
carefully
cemented
on
to
the
Engine
;
and
then
we
found
,
as
we
had
conjectured
,
that
usually
at
the
first
Exuction
(
though
sometimes
not
till
the
second
)
the
Glass-plate
would
be
broken
inwards
with
such
violence
,
as
to
be
shatter'd
into
a
great
multitude
of
small
fragments
,
and
(
which
was
remarkable
)
the
irruption
of
the
external
Air
driving
the
Glass
inwards
did
constantly
make
a
loud
Clap
,
almost
like
the
Report
of
a
Pistol
.
Which
Phaenomenon
,
whether
it
may
help
us
to
discover
the
cause
of
that
great
noise
,
that
is
made
upon
the
discharging
of
Guns
,
(
for
the
Recoyl
seems
to
depend
upon
the
Dilatation
and
Impulse
of
the
Powder
,
)
I
must
not
stay
to
consider
.
EXPERIMENT
VI.
Shewing
,
that
the
breaking
of
Glass-plates
in
the
foregoing
Experiment
,
need
not
to
be
ascrib'd
to
the
Fuga
Vacui
.
THough
I
long
since
inform'd
you
,
that
in
the
Experiments
I
then
presented
Your
Lordship
,
it
was
not
my
purpose
to
deliver
my
own
Opinion
whether
there
be
a
Vacuum
,
or
no
,
and
though
I
do
not
in
this
Tract
intend
to
declare
my self
either
way
;
yet
,
that
I
may
on
this
occasion
also
show
,
that
the
Pressure
of
the
Air
may
suffice
to
account
for
divers
Phaenomena
,
which
according
to
the
vulgar
Philosophers
must
be
referr'd
to
Natures
abhorrency
of
a
Vacuum
,
I
will
illustrate
the
foregoing
Experiment
by
another
,
the
substance
whereof
is
this
.
That
if
,
instead
of
the
above
mentioned
brass
Hoop
,
both
whose
Orifices
are
of
equal
breadth
,
you
imploy
a
hollow
(
but
taller
)
piece
of
Brass
,
or
(
which
is
more
easily
made
)
of
Latton
,
shap'd
like
a
Conus
iruncatus
,
or
a
Sugar-loaf
,
whose
upper
part
is
taken
off
parallel
to
the
bottom
;
and
if
you
make
the
two
Orifices
of
a
breadth
sufficiently
unequal
,
as
if
the
larger
being
made
as
wide
as
that
of
our
Brass-hoop
,
the
straiter
were
less
than
an
Inch
in
Diameter
;
You
will
find
,
that
if
this
piece
of
Metal
be
made
use
of
,
as
the
other
was
in
the
foregoing
Experiment
,
the
flat
Glass
cemented
on
to
the
Orifice
,
will
be
easily
broken
,
as
formerly
when
t
is
fastned
to
the
wider
Orifice
;
but
if
the
straiter
Orifice
be
turn'd
upward
,
the
Glass
that
covers
it
,
if
it
be
of
a
due
thickness
,
(
though
no
thicker
than
the
former
,
)
will
remain
entire
,
notwithstanding
the
withdrawing
of
the
Air
from
beneath
it
:
Which
seems
sufficiently
to
argue
,
that
t
is
not
precisely
Natures
abhorrency
of
a
vacuum
,
that
is
the
cause
why
Glasses
are
usually
broken
in
such
Experiments
,
since
whether
the
wider
or
the
narrower
Orifice
be
uppermost
,
and
cover'd
,
(
the
Metalline
part
of
the
vessel
being
the
same
,
and
onely
varying
its
posture
,
)
the
capacity
of
the
exhausted
vessel
will
be
equal
;
and
therefore
Nature
ought
to
break
the
Glass
as
well
in
one
case
as
the
other
,
which
yet
the
Experiment
shows
she
does
not
.
Wherefore
this
Diversity
seems
much
better
explicable
by
saying
,
that
when
the
wider
Orifice
is
uppermost
,
the
Glass
that
covers
it
must
serve
for
the
Basis
of
a
large
Atmospherical
Pillar
,
which
by
its
great
weight
may
easily
force
the
resistance
of
the
Glass
:
whereas
when
the
smaller
Orifice
is
uppermost
,
there
leans
upon
its
Cover
but
so
slender
a
Pillar
of
the
Atmosphere
,
that
the
natural
tenacity
or
mutual
cohaesion
of
parts
in
the
Glass
is
not
to
be
surmounted
by
a
weight
that
is
no
greater
.
EXPERIMENT
VII
.
About
a
convenient
way
of
breaking
blown
Bladders
by
the
Spring
of
the
Air
included
in
them
:
THe
foregoing
Experiments
having
sufficiently
manifested
the
strength
of
the
Airs
Spring
upon
fluid
Bodies
,
I
next
thought
fit
to
try
,
whether
the
force
of
a
little
included
Air
would
also
upon
consistent
and
even
Solid
bodies
emulate
the
Operations
of
the
weight
of
the
Atmosphere
.
In
the
prosecution
of
which
Enquiry
we
thought
fit
to
make
two
sorts
of
Tryals
:
the
one
,
where
the
Air
is
included
in
the
Bodies
,
on
which
its
Spring
does
work
;
and
the
other
,
where
t
is
External
to
them
.
Of
the
first
sort
are
this
7th
,
and
the
two
following
Experiments
;
and
of
the
second
sort
are
some
other
Tryals
,
to
be
comprehended
under
the
10th
Experiment
.
Having
formerly
mention'd
to
Your
Lordship
,
that
we
were
several
times
able
(
though
sometimes
not
without
much
difficulty
)
to
make
a
blown
Bladder
break
with
the
Spring
of
its
own
Air
;
I
should
not
think
it
worth
while
to
say
any
thing
here
about
the
same
Phaenomenon
,
but
that
(
besides
that
it
seems
odd
enough
,
and
is
not
unpleasant
to
many
Spectators
,
)
it
may
deserve
not
to
be
wholly
neglected
,
because
a
Good
way
to
break
Bladders
in
the
much
Exhausted
Receiver
,
may
sometimes
prove
an
useful
Expedient
,
especially
in
such
cases
where
the
Experimenter
(
who
sometimes
either
is
not
skilful
enough
,
or
well
enough
furnish'd
with
accommodations
to
regulate
the
ingress
of
the
Air
)
would
very
suddainly
supply
the
Receiver
with
fresh
Air
,
when
it
has
been
much
emptied
,
without
danger
of
letting
in
too
much
Air
from
without
.
Not
to
mention
,
that
the
Air
,
included
in
the
Bladder
to
be
broken
,
may
be
so
mingled
with
streams
,
or
imbu'd
with
divers
qualities
,
as
to
be
much
fitter
than
common
Air
for
some
particular
Purposes
.
We
shall
then
for
the
affinities
sake
between
this
Tryal
and
the
former
,
subjoyn
now
the
way
,
by
which
we
seldom
fail'd
of
breaking
Bladders
in
our
emptied
Receivers
.
For
this
purpose
,
the
blown
Bladder
that
was
to
be
burst
,
having
the
neck
very
closely
and
strongly
tyed
,
was
kept
a
pretty
while
in
the
Receiver
,
whilst
the
Air
was
pumping
out
,
and
then
taken
out
again
,
that
,
now
the
fibres
were
stretcht
and
relax'd
,
the
Capacity
being
lessen'd
by
a
new
ligature
that
I
order'd
to
be
strongly
made
near
the
Neck
,
the
Bladder
might
be
lessen'd
though
the
Air
were
but
the
same
,
and
the
Membrance
being
not
so
capable
of
yielding
as
before
,
upon
the
second
exhaustion
of
the
Receiver
the
Bladder
in
it
would
break
,
far
more
easily
then
otherwise
,
and
perhaps
be
oddly
enough
lacerated
.
We
sometimes
also
varied
this
way
of
disposing
Bladders
to
be
burst
,
by
omitting
the
preparatory
putting
in
of
the
Bladder
into
the
Receiver
,
and
onely
taking
it
in
a
little
near
the
Neck
,
that
,
the
Bladder
having
not
been
blown
very
full
at
first
,
the
tension
of
the
included
Air
might
be
greater
.
But
this
last
way
is
to
be
made
use
of
,
when
the
thing
we
desire
is
,
that
the
Bladder
by
breaking
at
a
certain
time
may
part
with
its
Air
,
and
not
when
t
is
onely
to
give
an
instance
of
the
force
of
the
Spring
of
uncompress'd
Air
against
the
sides
of
the
Vessel
that
contain
it
.
EXPERIMENT
VIII
.
About
the
lifting
up
a
considerable
Weight
by
the
bare
Spring
of
a
little
Air
included
in
a
Bladder
.
YOu
will
easily
believe
,
that
the
Force
imploy'd
(
in
the
foregoing
Experiment
)
by
the
Air
,
to
break
the
well
blown
Bladders
t
is
included
in
,
is
considerable
,
if
I
here
adde
,
that
a
small
quantity
of
Air
,
which
will
not
fill
¼
of
a
Bladder
,
will
not
onely
serve
to
blow
it
quite
up
,
but
will
manifestly
swell
it
,
though
that
Effect
be
oppos'd
not
onely
by
the
resistance
of
the
Bladder
it self
,
but
by
a
considerable
weight
tied
to
the
bottom
of
it
,
as
in
the
following
Experiment
.
We
took
a
middle
siz'd
Bladder
(
of
a
Hog
or
Sheep
,
)
and
having
press'd
out
the
Air
,
till
there
remain'd
but
about
a
fourth
or
fifth
part
(
by
guess
,
)
we
caus'd
the
Neck
to
be
very
strongly
tyed
up
again
:
also
round
about
the
opposite
part
of
the
Bladder
,
within
about
an
inch
of
the
bottom
,
we
so
strongly
tyed
another
String
,
that
it
would
not
be
made
to
slip
off
by
a
not
inconsiderable
weight
we
hung
at
it
.
Then
fastning
the
Neck
of
the
Bladder
to
the
turning
Key
,
we
convey'd
the
Bladder
and
the
Weight
hanging
at
it
into
a
large
Receiver
,
in
which
when
it
began
to
be
pretty
well
exhausted
,
the
Air
within
the
Bladder
being
freed
from
the
wonted
Pressure
of
the
Air
without
it
,
did
by
its
own
Spring
manifestly
swell
,
and
thereby
notably
shorten
the
Bladder
that
contain'd
it
,
and
by
consequence
visibly
lifted
up
the
Weight
,
(
that
resisted
that
change
of
figure
,
)
which
exceeded
15
pound
of
16.
ounces
to
the
Pound
.
After
that
we
took
a
larger
Bladder
,
and
having
let
out
so
much
Air
,
that
it
was
left
lank
enough
,
we
fasten'd
the
two
ends
of
it
to
the
upper
part
of
the
Receiver
,
(
for
which
else
it
would
have
been
too
long
,
)
and
tyed
a
Weight
(
but
not
the
same
)
so
as
that
it
hung
down
from
the
middle
of
the
Bladder
;
then
exhausting
the
Receiver
as
before
,
though
the
Bladder
,
and
this
new
Weight
which
stretcht
it
,
reach'd
so
low
,
as
that
for
a
while
we
could
scarce
see
whether
it
hung
in
the
Air
or
no
,
yet
at
length
we
perceiv'd
the
Bladder
to
swell
,
and
concluded
that
it
had
lifted
up
its
Clog
about
an
Inch
;
which
was
confirm'd
by
the
return
we
permitted
of
the
Air
into
the
Receiver
,
upon
which
the
Bladder
became
more
wrinkled
than
before
,
and
the
Weight
descended
,
which
being
taken
off
,
and
weighed
in
a
Statera
,
amounted
to
abovt
28
Pounds
.
We
would
have
reiterated
the
Experiment
,
but
so
heavy
a
Weight
having
broken
the
Bladder
,
we
were
discouraged
from
proceeding
any
farther
,
especially
in
regard
of
the
difficulty
of
bringing
by
this
contrivance
the
strength
of
the
Airs
Spring
to
any
exact
computation
,
though
it
sufficiently
shews
what
I
design'd
it
should
,
namely
that
the
Spring
of
a
little
included
Air
may
be
able
even
in
so
slight
a
contrivance
to
raise
a
great
Weight
.
Whether
this
Experiment
may
any
way
illustrate
the
motion
of
Muscles
,
made
by
Inflation
,
Contraction
,
&c.
it
belongs
not
to
this
place
to
consider
.
EXPERIMENT
IX
.
About
the
breaking
of
Hermetically
seal'd
Bubbles
of
Glass
by
the
bare
Spring
of
their
own
Air.
I
Shall
premise
to
the
following
Tryals
an
Experiment
,
wherein
Uncompress'd
Air
is
made
by
its
own
bare
Spring
to
break
the
solid
body
it self
t
is
shut
up
in
.
And
this
I
the
rather
set
down
before
the
subsequent
Tryals
,
Physico-Mechanical
Experiments
mention
has
been
made
of
this
Tryal
,
as
of
one
that
we
could
not
then
make
to
succeed
;
we
have
since
,
imploying
smaller
Receivers
,
made
it
often
enough
prosperously
,
somewhat
to
the
wonder
of
eminent
Virtuosi
,
who
confess'd
to
me
they
had
made
frequent
and
divers
attempts
to
perform
the
same
thing
,
without
ever
succeeding
in
any
of
them
.
But
it
will
not
be
requisite
to
multiply
relations
about
this
Particular
,
and
therefore
I
shall
set
down
but
this
one
,
which
I
meet
with
among
my
loose
Notes
.
A
large
Glass
Bubble
Hermetically
seal'd
being
put
into
the
Receiver
,
and
the
Air
drawn
out
as
much
as
in
usual
Operations
,
and
somewhat
more
,
though
I
told
the
Company
before
hand
that
I
had
several
times
observ'd
,
that
such
Bubbles
would
not
break
immediately
,
but
somewhile
after
the
withdrawing
the
Air
from
about
them
,
yet
this
continued
so
long
entire
after
we
had
left
off
Pumping
,
that
presuming
it
had
been
blown
too
strong
,
I
began
to
dispair
of
the
Experiments
succeeding
;
when
,
whilst
we
were
providing
something
else
to
put
into
the
Receiver
,
and
as
I
guess'd
4.
minuts
after
the
Pump
had
been
let
alone
,
the
Bubble
surpriz'd
us
with
its
being
broken
with
such
violence
by
the
Spring
of
the
included
Air
,
that
the
fragments
of
it
were
dash'd
every
way
against
the
sides
of
the
Receiver
,
and
broken
so
very
small
,
that
when
we
came
to
take
it
up
,
the
Powder
was
by
the
By-standers
compar'd
to
the
small
Sand
wont
to
be
imploy'd
to
dry
Papers
,
that
have
been
newly
writ
upon
with
Inck.
The
Reason
why
the
Bubble
broke
so
slowly
I
cannot
now
stay
to
propose
,
no
more
then
to
examine
whether
the
difficulty
of
breaking
vessels
of
Glass
,
no
thicker
then
these
Bubbles
,
proceed
from
some
weakning
of
the
Spring
of
imprisoned
Air
,
by
its
stretching
a
little
the
including
Glass
,
(
for
in
another
case
we
have
observ'd
this
Glass
to
be
stretchable
by
the
pressure
of
Air
;
)
or
from
hence
,
that
't
was
very
hard
,
as
I
have
elsewhere
mention'd
,
to
avoid
rarifying
the
Air
a
little
,
and
consequently
weakning
its
Spring
,
by
the
heat
that
was
necessary
to
be
imploy'd
about
the
sealing
up
the
Bubble
.
EXPERIMENT
X.
Containing
two
or
three
Tryals
of
the
force
of
the
Spring
of
our
Air
uncompress'd
upon
stable
and
even
solid
Bodies
,
(
whereto
t
is
external
.
)
IN
prosecution
of
the
Enquiry
propos'd
in
the
Title
,
we
made
(
among
others
)
the
following
Tryals
.
The
I.
TRYAL
.
1.
WE
took
the
Brass-hoop
,
mention'd
in
the
5th
Experiment
,
(
whose
Diameter
is
somewhat
above
3.
Inches
,
)
and
having
caus'd
a
Glazier
to
cut
some
Plates
of
Glass
,
such
as
are
used
for
making
the
Quarrels
of
Windows
,
till
he
had
brought
them
to
a
Size
,
&
a
roundness
fit
to
serve
for
Covers
to
that
brass-hoop
,
we
carefully
fasten'd
one
of
them
with
Cement
to
the
upper
Orifice
of
the
Hoop
or
Ring
,
and
then
cementing
the
lower
Orifice
to
the
Engine
,
so
that
the
Vessel
,
compos'd
of
the
Metal
and
Glass
,
serv'd
for
a
small
Receiver
;
we
whelm'd
over
it
a
large
and
strong
Receiver
,
which
we
also
fasten'd
on
to
the
Engine
with
Cement
after
the
usual
manner
.
By
which
Contrivance
it
was
necessary
,
that
when
the
Pump
was
set
on
work
,
the
included
Receiver
(
of
Brass
and
Glass
)
should
have
its
Air
withdrawn
,
and
yet
the
Air
in
the
larger
Receiver
should
not
be
pump'd
out
but
by
breaking
through
the
Glass
,
so
that
the
internal
Air
of
the
Metalline
Receiver
(
as
we
may
call
it
for
distinctions
sake
)
being
pump'd
out
,
the
Glass
Plate
,
that
made
part
of
that
Receiver
,
must
lye
expos'd
to
the
pressure
of
the
Ambient
Air
shut
up
in
the
other
Receiver
,
without
having
the
former
assistance
of
the
now
withdrawn
Air
to
resist
the
Pressure
;
wherefore
,
as
we
expected
,
at
the
first
or
second
Exuction
of
the
Air
,
included
in
the
small
metalline
Receiver
,
the
Glass-plate
was
,
by
the
Pressure
of
the
incumbent
Air
,
contain'd
in
the
great
Receiver
,
broken
into
an
100
pieces
,
which
were
beaten
inwards
into
the
Cavity
of
the
Hoop
.
The
II.
Tryal
.
2.
This
done
,
to
shew
that
there
needed
not
the
Spring
of
so
great
a
quantity
of
included
Air
to
break
such
Glasses
,
we
took
another
Roundish
one
,
which
,
though
wide
enough
at
the
Orifice
to
cover
the
Brass
Ring
&
the
new
Glass-plate
that
we
had
cemented
on
it
,
was
yet
so
low
,
that
we
estimated
it
to
hold
but
a
6th
part
of
what
the
large
Receiver
,
formerly
imploy'd
,
is
able
to
contain
;
and
having
whelm'd
this
smaller
vessel
,
which
was
shap'd
like
those
Cups
they
call
Tumblers
,
over
the
Metalline
Receiver
,
and
well
fasten'd
it
to
the
Engine
with
Cement
,
we
found
that
though
this
External
Receiver
had
a
great
part
of
its
Cavity
fill'd
by
the
included
one
,
yet
when
this
Internal
one
was
exhausted
by
an
Exuction
or
two
,
the
Spring
of
the
little
Air
that
remain'd
,
was
able
to
break
the
Plate
into
a
multitude
of
fragments
.
The
III.
Tryal
.
3.
Because
the
Glass-Plates
hitherto
mention'd
seem'd
not
so
thick
,
but
that
the
Pressure
of
the
included
Air
might
be
able
to
give
considerabler
Instances
of
its
Force
;
in
stead
of
the
Metalline
Receivers
hitherto
employed
,
we
took
a
square
Bottle
of
Glass
,
which
we
judg'd
to
be
able
to
contain
about
a
Pint
(
or
Pound
)
of
Water
,
and
which
had
been
provided
to
keep
subtle
Chymical
Liquors
in
,
for
which
use
we
are
not
wont
to
choose
weak
ones
.
This
we
inverted
,
and
apply'd
to
the
Engine
as
a
Receiver
,
over
which
we
whelm'd
the
large
Receiver
formerly
mention'd
;
and
having
cemented
it
on
,
as
in
the
foregoing
Experiments
,
we
set
the
Pump
on
work
to
empty
the
internal
Receiver
,
(
or
square
Bottle
,
)
by
which
means
the
withdrawing
of
the
Air
,
and
the
figure
of
the
vessel
(
which
was
inconvenient
for
resisting
)
suffer'd
the
Pressure
of
the
Air
included
in
the
external
Receiver
to
crush
the
viol
into
a
great
number
of
pieces
.
And
to
vary
this
Experiment
,
as
we
did
that
of
breaking
the
metalline
Receivers
,
we
took
another
Glass
of
the
shape
and
about
the
bigness
of
the
former
,
and
having
apply'd
it
to
the
Engine
as
before
,
and
cover'd
it
with
a
Receiver
that
was
little
higher
than
it self
,
we
found
,
that
upon
the
exhaustion
of
the
Air
the
second
square
Glass
was
likewise
broken
into
many
fragments
,
some
of
which
were
of
so
great
a
thickness
,
as
mov'd
some
wonder
,
that
the
bare
Pressure
of
the
Air
was
able
to
break
such
a
vessel
,
though
probably
the
Cracks
,
that
reacht
to
them
,
were
begun
in
much
weaker
parts
of
the
Glass
.
NB.
1.
The
bottoms
and
the
necks
of
both
these
square
Bottles
were
entire
enough
;
by
which
it
seem'd
probable
,
that
the
vessels
had
been
broken
by
the
Pressure
of
the
Air
against
the
Sides
,
which
were
not
onely
thinner
than
the
parts
above
named
,
but
expos'd
a
larger
Superficies
to
the
lateral
Pressure
of
the
Air
,
than
to
the
perpendicular
.
2.
We
observ'd
in
one
of
the
two
last
Experiments
,
that
the
Vessel
did
not
break
presently
upon
the
last
Exuction
that
was
made
of
the
included
Air
,
but
a
considerable
time
after
,
which
it
seems
was
requisite
to
allow
the
comprest
parts
of
the
Glass
time
to
change
their
places
;
and
this
Phaenomenon
I
therefore
mention
,
because
the
same
thing
that
here
happen'd
in
the
breaking
a
Glass
inwards
by
the
Spring
of
the
Air
,
I
elsewhere
observ'd
to
have
happen'd
in
breaking
a
Glass
outwards
by
the
same
Spring
.
3.
To
confirm
,
that
it
is
the
Spring
of
the
External
Receivers
Air
that
is
the
Agent
in
those
Fractures
of
Glasses
,
and
to
prevent
or
remove
some
scruples
,
we
thought
fit
to
make
this
variation
in
the
Experiment
.
We
applyed
a
Plate
of
Glass
,
just
like
those
formerly
mentioned
,
to
the
Brass-hoop
;
but
in
the
cementing
of
it
on
,
we
plac'd
in
the
thickness
of
the
Cement
a
small
Pipe
of
Glass
of
about
an
Inch
long
,
whose
Cavity
was
not
so
big
as
that
of
a
Straw
,
and
which
being
left
open
at
both
the
ends
might
serve
for
a
little
Channel
,
through
which
the
Air
might
pass
from
the
External
Receiver
to
the
Internal
;
over
This
we
whelm'd
one
of
the
small
Receivers
above
mentioned
,
&
then
,
though
we
set
the
Pump
on
work
much
longer
then
would
have
needed
if
this
litle
Pipe
had
not
been
made
use
of
,
we
found
,
as
we
expected
,
that
the
Internal
Receiver
continued
entire
,
because
the
Air
,
whose
Spring
should
have
broken
it
,
having
liberty
to
pass
through
the
Pipe
,
and
consequently
to
expand
it self
into
the
place
deserted
by
the
Air
pump'd
out
,
did
by
that
Expansion
weaken
its
Spring
too
much
,
to
retain
strength
enough
to
break
the
Metalline
(
or
Internal
)
Receiver
.
But
here
t
is
to
be
noted
,
that
either
the
Pipe
must
be
made
bigger
than
that
lately
mentioned
,
or
the
Exuction
of
the
Air
must
not
be
made
by
the
Pump
as
nimbly
as
we
can
,
or
otherwise
the
Plate
of
Glass
may
be
broken
notwithstanding
the
Pipe
;
because
the
Air
contain'd
in
the
External
Receiver
,
having
a
force
much
greater
than
is
necessary
to
break
such
a
Plate
,
it
may
well
happen
(
as
I
have
sometimes
found
it
do
)
that
if
the
Air
be
hastily
drawn
out
of
the
Internal
Receiver
,
that
Air
,
which
should
succeed
in
its
room
,
cannot
get
fast
enough
out
of
that
external
Receiver
through
so
small
a
Pipe
,
and
the
Air
remaining
in
that
external
Receiver
will
yet
retain
a
Spring
strong
enough
to
break
the
Glass
.
To
illustrate
which
,
I
shall
propose
this
Experiment
,
That
sometimes
,
when
I
have
at
the
flame
of
a
Lamp
caus'd
Glass
Bubbles
to
be
blown
with
exceeding
slender
Stems
,
if
they
were
nimbly
remov'd
out
of
the
flame
whilst
they
were
ignited
,
they
would
according
to
my
conjecture
be
either
broken
,
if
they
cool'd
too
fast
;
or
compress'd
inward
,
if
they
long
enough
retain'd
the
Softness
they
had
given
them
by
Fusion
.
For
the
Air
in
the
Bubble
being
exceedingly
rarified
and
expanded
,
whilst
the
Glass
is
kept
in
the
flame
,
and
coming
to
cool
hastily
when
remov'd
from
thence
,
looses
upon
refrigeration
the
Spring
the
heat
had
given
it
,
and
so
,
if
the
External
Air
cannot
press
in
fast
enough
through
the
too
slender
Pipe
,
there
will
not
get
in
Air
enough
to
resist
the
Pressure
of
the
Atmosphere
,
and
therefore
if
this
Pressure
find
the
Bubble
yet
soft
,
it
will
press
it
a
little
inwards
,
and
either
flatten
it
,
or
make
a
dimple
in
it
,
though
the
Orifice
of
the
Pipe
be
left
open
.
EXPERIMENT
XI
.
Shewing
,
that
Mercury
will
in
Tubes
be
raised
by
Suction
no
higher
then
the
weight
of
the
Atmosphere
is
able
to
impell
it
up
.
T
Is
sufficiently
known
,
that
the
common
opinion
of
Philosophers
,
and
especially
of
those
which
follovv
Aristotle
,
has
long
been
,
and
still
is
,
that
the
cause
of
the
Ascension
of
Water
upon
Suction
,
and
particularly
in
those
Pumps
,
where
the
Water
seems
of
its
own
accord
to
follow
the
rising
Sucker
,
is
Natures
abhorrency
of
a
Vacuum
.
Against
this
receiv'd
Opinion
divers
of
the
Modern
Philosophers
have
oppos'd
themselves
.
But
as
some
of
them
were
Vacuists
,
and
others
Plenists
,
they
have
explicated
the
Ascension
of
Water
in
Sucking-pumps
upon
very
different
grounds
;
so
that
many
Ingenious
men
continue
yet
irresolv'd
in
this
noble
Controversie
.
Wherefore
though
I
have
formerly
made
,
and
now
renew
a
solemn
Profession
,
that
I
do
not
in
this
Treatise
intend
to
declare
either
for
or
against
the
being
of
a
Vacuum
;
and
though
I
have
[
*
](A28949-e4500-b)
*
The
place
here
meant
is
a
passage
in
the
Author's
Examen
of
Mr.
Hobbs
his
Dialogue
about
the
Air.
elsewhere
occasionally
acknowledg'd
my Self
not
to
acquiesce
fully
in
what
either
the
ancient
or
the
modern
Philosophers
have
taught
about
the
adequate
cause
of
Suction
;
(
in
the
assigning
of
which
,
I
think
,
I
have
shown
them
to
have
been
somewhat
deficient
,
)
yet
since
I
think
some
Experiments
,
of
importance
to
this
Controversie
,
may
be
better
made
by
the
help
of
our
Engine
,
than
they
have
been
by
any
Instrument
I
have
yet
heard
of
,
I
shall
now
adde
the
Tryals
I
made
,
to
shew
both
that
whether
there
be
or
may
be
a
Vacuum
or
not
,
there
is
no
need
to
have
recourse
to
a
fuga
vacui
to
explicate
Suction
;
and
also
that
whatever
other
Causes
have
by
Gassendus
and
Cartesius
been
ingeniously
propos'd
to
explicate
Suction
,
it
seems
to
depend
clearly
upon
the
Weight
of
the
Atmosphere
,
or
in
some
cases
upon
the
Spring
of
the
Air
;
though
I
deny
not
,
that
other
Causes
may
contribute
to
that
Pressure
of
the
Air
,
which
I
take
to
be
the
grand
and
immediate
Agent
in
these
Phaenomena
.
We
took
a
Brass-Pipe
bended
like
a
Siphon
,
and
fitted
at
the
bigger
end
with
a
Stop-cock
&c
,
By
which
it
seems
manifest
enough
,
that
whatever
many
Learned
men
have
taught
,
or
others
do
yet
believe
about
the
unlimited
power
that
Nature
would
exercise
,
to
prevent
what
they
call
a
Vacuum
;
yet
this
power
has
its
bounds
,
and
those
depend
not
so
much
upon
the
Exigency
of
that
Principle
,
which
the
School-men
call
a
fuga
vacui
,
as
upon
the
specifick
Gravity
of
the
Liquor
to
be
rais'd
by
Suction
.
For
confirmation
of
which
,
we
substituted
in
stead
of
the
stagnant
Mercury
a
bason
of
Water
,
and
though
instead
of
the
many
Sucks
we
had
fruitlesly
imploy'd
to
raise
the
Quick-silver
above
the
lately
mentioned
height
,
we
now
imploy'd
but
one
Exsuction
,
(
or
less
then
a
full
one
,
)
which
did
but
in
part
empty
the
Exhausting
Siphon
:
yet
the
Water
upon
the
opening
of
the
Stop-cock
was
not
onely
impell'd
to
the
very
top
of
the
Glass-Cane
,
but
likewise
continued
running
for
a
good
while
through
the
Exhausting
Siphon
,
and
thence
fell
upon
the
plate
of
the
Engine
;
so
that
it
seem'd
an
odd
spectacle
to
those
that
knew
not
the
reason
of
it
,
to
see
the
Water
running
very
briskly
of
its
own
accord
as
they
imagined
out
of
the
shorter
leg
of
a
Siphon
;
especially
that
leg
being
perhaps
not
above
a
a
quarter
so
long
as
the
other
.
And
here
I
must
not
omit
this
considerable
circumstance
,
that
though
sometimes
in
the
Torricellian
Experiment
I
have
observ'd
the
Mercury
to
stand
at
thirty
inches
,
and
now
and
then
above
it
,
yet
the
height
of
the
Mercury
elevated
in
our
Glass-Cane
appear'd
not
,
when
measured
,
to
reach
fully
29.
inches
and
a
quarter
,
which
I
thought
it
was
not
difficult
to
render
a
reason
of
,
from
the
varying
weight
of
the
Atmosphere
;
and
accordingly
consulting
the
Baroscope
,
(
that
stood
in
another
room
,
)
I
found
the
Atmosphere
to
be
at
that
time
somewhat
light
,
the
Quick-silver
in
it
being
in
height
but
29.
inches
and
an
eighth
,
which
probably
would
have
been
the
very
height
of
the
Quick-silver
rais'd
by
the
Engine
,
if
it
had
had
time
by
standing
to
free
it self
from
Bubbles
.
From
whence
we
may
conclude
,
that
Suction
will
elevate
liquors
in
Pumps
no
higher
then
the
weight
of
the
Atmosphere
is
able
to
raise
them
,
since
the
closeness
requisite
in
the
Pump
of
our
Engine
to
be
stanch
makes
it
very
unlikely
,
that
by
any
ordinary
Pump
a
more
accurate
Suction
can
be
effected
.
I
have
nothing
to
adde
about
the
related
Experiment
but
this
one
;
that
it
may
afford
us
a
notable
confirmation
of
the
argument
we
formerly
propos'd
against
them
,
that
ascrib'd
the
elevation
and
sustentation
of
the
Quick-silver
in
the
Torricellian
Experiment
to
a
certain
rarified
Air
,
which
the
more
highly
it
is
rarified
,
the
greater
power
it
acquires
to
attract
Quick-silver
,
and
other
contiguous
Bodies
;
for
in
our
Experiment
though
by
continuing
to
pump
we
can
rarifie
or
distend
more
and
more
the
Air
in
the
Exhausting
Siphon
,
yet
we
were
not
able
to
raise
the
Mercury
above
30
inches
,
(
which
exceeds
not
the
height
to
which
the
Atmosphere
is
able
to
elevate
it
,
)
and
this
,
though
,
the
stagnant
Mercury
being
exposed
to
the
free
Air
,
it
cannot
be
pretended
(
as
in
some
other
cases
it
may
,
though
not
satisfactorily
,
be
done
)
that
the
Mercury
cannot
be
raised
higher
,
without
offering
violence
to
the
body
incumbent
on
the
stagnant
Mercury
:
for
in
the
Experiment
we
are
considering
if
Nature
should
raise
the
Quick-silver
higher
and
higher
in
the
Pipe
,
to
succeed
in
the
room
of
the
Air
that
is
withdrawn
;
the
formerly
Stagnant
Mercury
,
that
would
on
this
occasion
be
rais'd
,
might
be
immediately
succeeded
by
the
free
and
undilated
Air
,
so
that
Nature
would
be
put
to
offer
violence
to
the
Quick-silver
onely
,
which
if
she
were
scrupulous
to
do
,
what
ayl'd
her
to
raise
it
(
as
she
did
in
our
Tryal
)
against
the
inclinations
of
so
ponderous
a
body
,
to
above
29.
Inches
high
?
Annotation
.
Though
the
Exhausting
Siphon
,
mentioned
at
the
beginning
of
this
Experiment
,
may
be
easily
enough
conceiv'd
by
an
attentive
inspection
of
the
Figure
,
yet
because
I
frequently
make
use
of
it
in
Pneumatical
Experiments
,
t
will
not
be
amiss
to
intimate
here
once
for
all
these
three
particulars
about
it
.
1.
That
though
the
bending
Pipe
its
self
may
be
for
some
uses
more
conveniently
made
of
Glass
than
of
Metal
,
because
the
Transparency
of
the
former
may
inable
us
to
discover
what
passes
in
it
;
yet
for
the
most
part
we
choose
to
imploy
Pipes
of
the
latter
sort
,
because
the
others
are
so
very
subject
to
break
.
2.
That
t
is
convenient
to
make
the
longer
leg
of
the
Siphon
a
little
larger
at
the
bottom
than
the
rest
of
the
Pipe
usually
needs
to
be
,
that
it
may
the
more
commodiously
admit
the
shank
of
a
Stop-cock
,
which
is
to
be
very
carefully
inserted
with
Cement
;
by
seasonably
turning
and
returning
of
which
Stop-cock
,
the
passage
(
for
the
Air
)
between
the
Engine
and
the
Vessel
to
be
exhausted
is
to
be
opened
and
shut
.
3.
That
though
we
sometimes
content
our selves
to
apply
immediately
the
brass
Siphon
its
self
to
the
Engine
,
by
fastning
with
Cement
the
external
shank
of
the
Stop-cock
to
the
Orifice
of
the
little
Pipe
,
through
which
the
Excuction
of
the
Air
is
made
;
yet
the
bended
Pipe
alone
,
if
it
be
not
almost
constantly
held
,
is
so
apt
to
be
loosen'd
by
the
motion
of
the
Engine
,
and
the
turning
of
the
Stopcock
,
(
which
frequently
occasions
Leaks
,
and
disturbs
the
Operation
,
)
that
for
the
most
part
we
make
use
of
a
Siphon
consisting
of
a
brass
Pipe
,
EXPERIMENT
XII
.
About
the
differing
Heights
whereto
Liquors
will
be
elevated
by
Suction
,
according
to
their
several
Specifick
Gravities
.
IF
,
when
I
was
making
the
foregoing
Experiment
,
I
had
been
able
to
procure
a
Pipe
long
enough
,
I
had
tried
to
what
height
I
could
raise
Water
by
Suction
,
though
I
would
have
done
it
rather
to
satisfie
Others
then
my self
,
who
scarce
doubted
,
but
that
as
Water
is
(
bulk
for
bulk
)
about
14
times
lighter
than
Quick-silver
:
so
it
would
have
been
rais'd
by
Suction
to
about
four
or
five
and
thirty
foot
,
(
which
is
14
times
as
high
as
we
were
able
to
elevate
the
Quick-silver
,
)
and
no
higher
.
But
being
not
furnished
for
the
Tryal
I
would
have
made
,
I
thought
fit
to
substitute
another
,
which
would
carry
the
former
Experiment
somewhat
further
.
For
whereas
,
in
That
,
we
shew'd
how
high
the
Atmosphere
was
able
by
its
whole
Gravitation
to
raise
Quick-silver
;
and
whereas
likewise
that
,
which
appears
in
Monsieur
Paschals
Experiment
,
is
,
at
what
height
the
whole
weight
of
the
Atmosphere
can
sustain
a
Cylinder
of
Water
:
by
the
way
that
I
thought
on
,
it
would
appear
,
(
which
hath
not
yet
(
that
I
know
of
)
been
shewn
,
)
how
a
part
of
the
Pressure
of
the
Air
would
in
perpendicular
Pipes
raise
not
onely
the
two
mentioned
Liquors
,
but
others
also
to
Heights
answerable
to
the
degree
of
Pressure
,
and
proportionable
to
the
specifick
Gravities
of
the
respective
Liquors
.
To
make
this
Tryal
the
more
clear
and
free
from
exceptions
,
I
caus'd
to
be
made
and
inserted
to
the
shorter
Leg
of
the
above
mentioned
Exhausting
Siphon
a
short
Pipe
;
which
brancht
it self
equally
to
the
right
hand
and
the
left
,
We
tried
also
the
proportion
of
these
two
Liquors
at
other
heights
,
but
could
not
easily
measure
thē
so
well
as
we
did
at
those
newly
mentioned
;
and
therefore
though
there
seem'd
to
be
some
slight
variation
,
yet
we
lookt
upon
it
but
as
what
might
be
well
imputed
to
the
difficulty
of
making
such
Experiments
exactly
;
and
this
displeas'd
me
not
in
these
Tryals
,
that
whereas
it
was
observ'd
,
and
somewhat
wondred
at
,
that
the
Quick-silver
for
the
most
part
seem'd
to
be
somewhat
(
though
but
a
very
little
)
higher
then
the
proportion
of
1
to
14
required
,
I
had
long
before
by
particular
Tryals
found
,
that
though
14
and
1
be
the
nearest
of
small
integer
numbers
that
express
the
proportion
between
the
Specifick
Gravities
of
Quicksilver
and
Water
,
yet
the
former
of
those
Fluids
(
or
at
least
that
which
I
made
my
Tryals
with
)
is
not
quite
so
heavy
as
this
proportion
supposes
,
though
I
shall
not
here
stay
to
determine
precisely
the
difference
,
having
done
it
in
another
Tract
,
where
the
method
I
imployed
in
the
investigation
of
it
is
also
set
down
.
The
above
mentioned
Experiment
,
made
by
the
help
of
our
Engine
,
as
to
Quick-silver
and
Water
being
confirmable
by
Tryals
(
to
be
by
and-by
mentioned
)
made
in
other
Liquors
,
affords
our
Hypothesis
two
considerable
advantages
above
the
vulgar
doctrine
of
the
Schools
,
(
for
I
do
not
apply
what
follows
to
all
the
Plenists
,
)
who
ascribe
the
ascension
of
Liquors
by
Suction
to
a
Traction
made
ob
fugam
vacui
,
as
they
are
wont
to
speak
.
For
first
it
is
manifestly
agreeable
to
our
Doctrine
,
that
,
since
the
Air
,
according
to
It
,
is
a
Fluid
that
is
not
void
of
Weight
,
it
should
raise
those
Liquors
that
are
lighter
,
as
Water
,
higher
then
those
that
are
ponderous
,
as
Quick-silver
;
and
that
answerably
to
the
disparity
of
their
Weights
▪
And
secondly
,
there
is
no
reason
why
,
if
the
Air
be
withdrawn
by
Suction
from
Quick
silver
and
Water
,
there
should
be
less
left
a
vacuum
above
the
one
then
above
the
other
,
in
case
either
of
them
succeed
not
in
the
place
deserted
by
the
Air
,
and
consequently
when
the
Air
is
withdrawn
out
of
both
the
forementioned
Glass-pipes
,
if
there
would
be
no
vacuum
in
case
no
liquor
should
succeed
it
,
why
does
Nature
needlesly
to
prevent
a
vacuum
make
the
Water
that
is
an
heavy
body
ascend
contrary
to
its
own
nature
,
according
to
which
it
tends
towards
the
Center
of
the
Earth
?
And
if
the
succeeding
of
a
liquor
be
necessary
to
prevent
a
vacuum
,
how
chance
that
Nature
does
not
elevate
the
Quick-silver
as
well
as
the
Water
,
especially
since
t
is
manifest
by
the
foregoing
Experiment
that
she
is
able
to
raise
that
ponderous
Liquor
above
26
inches
higher
than
she
did
in
the
Experiment
we
are
now
discoursing
of
.
Perhaps
it
would
not
be
amiss
to
take
notice
,
on
this
occasion
,
that
among
other
applications
of
this
Experiment
it
may
be
made
somewhat
useful
to
estimate
the
differing
Gravities
of
liquors
,
to
which
purpose
I
caus'd
to
be
put
under
the
bottom
of
the
forementioned
Glass
pipes
two
vessels
,
the
one
with
fresh
water
,
&
the
other
with
the
like
water
impregnated
with
a
good
proportion
of
Sea-salt
that
I
had
caus'd
to
be
dissolv'd
in
it
,
for
want
of
Sea-water
,
which
I
would
rather
have
imploy'd
.
And
I
found
,
that
when
the
fresh
water
was
rais'd
to
about
42
inches
,
the
Saline
solution
had
not
fully
reacht
to
40.
But
though
this
difference
were
double
to
that
which
the
proportion
and
Gravity
betwixt
our
Sea-water
and
fresh
water
would
have
required
,
yet
to
make
the
disparity
more
evident
,
and
also
because
I
would
be
able
the
better
to
guess
at
the
proportion
of
the
dissolv'd
Salt
by
making
it
as
great
as
I
could
,
I
caus'd
an
unusual
Brine
to
be
made
,
by
suffering
Sea-salt
to
deliquate
in
the
moist
Air.
And
having
applyed
this
Liquor
and
fresh
water
to
the
two
already
mentioned
Pipes
,
and
proceeded
after
the
former
manner
,
we
found
that
when
the
pure
water
was
elevated
to
near
42
Inches
,
the
liquor
of
Sea-salt
wanted
about
7.
Inches
and
a
quarter
of
that
height
;
and
when
the
water
was
made
to
subside
to
the
middle
of
its
Pipe
,
or
thereabouts
,
the
Saline
liquor
in
the
other
Pipe
was
between
3
and
4
inches
lower
then
it
.
I
would
have
tryed
the
difference
between
these
Liquors
and
Oyl
,
but
the
Coldness
of
the
Weather
was
unfavourable
to
such
a
Tryal
:
but
to
shew
a
far
greater
Disparity
then
That
would
have
done
betwixt
the
height
of
Liquors
of
unequal
Gravities
,
I
took
fair
Water
,
and
a
liquor
made
of
the
Salt
of
Pot-ashes
suffered
to
run
in
a
Sellar
per
deliquium
,
(
this
being
one
of
the
ponderousest
Liquors
I
have
prepar'd
,
)
and
having
proceeded
as
in
the
former
Tryals
,
I
found
that
when
the
common
Water
was
about
42
inches
high
,
the
newly
mention'd
Solution
wanted
somewhat
of
30
inches
;
and
when
the
Water
was
made
to
subside
to
the
middle
of
its
Pipe
,
or
thereabouts
,
the
deliquated
Liquor
was
between
6
and
7
inches
lower
then
it
.
I
had
some
thoughts
,
when
I
applied
my self
to
make
these
Tryals
,
to
examine
how
well
we
could
by
this
new
way
compare
the
Saltness
of
the
waters
of
several
Seas
,
and
those
also
of
Salt-springs
;
and
likewise
whether
,
and
(
if
any
thing
near
)
how
far
we
might
by
this
Method
determine
the
proportion
of
the
more
simple
Liquors
that
may
be
mingled
in
compounded
ones
,
as
in
the
mixture
of
Water
and
Wine
,
Vinegar
and
Water
,
&c.
but
being
not
provided
with
Instruments
fit
for
such
nice
Tryals
,
and
a
mischance
having
impair'd
the
Glasses
lately
mentioned
before
the
last
Tryals
were
quite
ended
,
and
having
soon
after
broken
one
of
them
,
I
laid
aside
those
Thoughts
.
EXPERIMENT
XIII
.
About
the
Heights
to
which
Water
and
Mercury
may
be
rais'd
,
proportionably
to
their
specifick
Gravities
,
by
the
Spring
of
the
Air.
IN
prosecution
of
the
Parallel
formerly
begun
,
betwixt
the
Effects
of
the
Weight
of
the
Atmosphere
,
and
the
Spring
of
included
Air
,
we
thought
fit
after
the
foregoing
to
make
the
following
Experiment
.
We
took
a
strong
Glass-bottle
,
capable
to
hold
above
a
Pint
of
Water
,
and
having
in
the
bottom
of
it
lodg'd
a
convenient
quantity
of
Mercury
,
we
pour'd
on
it
a
greater
quantity
of
Water
,
(
because
this
Liquor
was
to
be
impell'd
up
many
times
higher
than
the
other
,
)
and
having
provided
two
slender
Glass-pipes
,
each
open
at
both
ends
,
we
so
plac'd
and
fastned
them
,
by
means
of
the
Cement
wherewith
we
choak'd
the
upper
part
of
the
neck
of
the
Bottle
,
that
the
shorter
of
the
Pipes
had
its
lower
Orifice
immerst
beneath
the
surface
of
the
Quick-silver
,
and
the
longer
Pipe
reacht
not
quite
so
low
as
that
Surface
,
and
so
was
immerst
but
in
the
Water
,
by
which
contrivance
we
avoided
the
necessity
of
having
two
distinct
vessels
for
our
two
stagnant
Liquors
,
which
would
have
been
inconvenient
in
regard
of
the
slenderness
of
the
upper
part
of
our
Receiver
.
This
done
,
we
conveyed
the
Bottle
into
a
fitly
shap'd
Receiver
,
(
formerly
describ'd
at
the
first
Experiment
,
)
and
having
begun
to
pump
out
the
Air
,
we
took
notice
to
what
heights
the
Quick-silver
and
Water
were
impell'd
up
in
their
respective
Tubes
,
on
which
we
had
before
made
marks
from
inch
to
inch
with
hard
Wax
,
(
that
they
might
not
be
remov'd
by
wet
or
rubbing
,
)
and
we
observ'd
,
that
when
the
Quicksilver
was
impell'd
up
to
two
inches
,
the
Water
was
rais'd
to
about
eight
and
twenty
;
and
when
the
Quick-silver
was
about
one
inch
high
,
the
Water
was
about
fourteen
.
I
say
,
about
,
partly
because
some
allowances
must
be
made
for
the
sinking
of
the
Superficies
of
the
Stagnant
Quicksilver
,
and
the
greater
subsidence
of
that
of
the
stagnant
Water
,
by
reason
of
the
Liquors
impell'd
into
the
two
Pipes
;
partly
because
that
the
breadth
of
the
Mark
of
wax
was
considerable
,
when
the
Quick-silver
was
but
about
an
inch
high
,
and
so
made
it
difficult
to
discern
the
exact
height
of
the
Metal
,
when
the
water
was
fallen
down
to
fourteen
inches
:
especially
in
regard
that
the
Quick-silver
never
ascending
so
high
as
the
neck
of
the
Bottle
,
(
which
the
water
left
far
beneath
it
,
)
the
thickness
of
the
Receiver
,
and
that
of
so
strong
a
Bottle
made
it
difficult
to
discern
so
clearly
the
station
of
the
Quick-silver
as
I
could
have
wished
.
EXPERIMENT
XIV
.
About
the
Heights
answerable
to
their
respective
Gravities
,
to
which
Mercury
and
Water
will
subside
,
upon
the
withdrawing
of
the
Spring
of
the
Air.
FOr
the
further
illustration
of
the
Doctrine
propos'd
in
the
last
and
some
of
the
foregoing
Experiments
,
about
the
raising
and
sustentation
of
Liquors
in
Pipes
by
the
Pressure
of
the
Air
;
I
thought
it
not
unfit
to
make
the
following
Tryal
,
though
it
were
easie
to
foresee
in
this
peculiar
Experiment
a
peculiar
difficulty
.
We
caus'd
then
to
be
convey'd
into
a
fitly
shap'd
Receiver
two
Pipes
of
Glass
very
uneven
in
length
,
but
each
of
them
seal'd
at
one
end
,
the
shorter
Tube
was
fill'd
with
Mercury
,
and
inverted
into
a
small
Glass
Jarr
,
wherein
a
sufficient
quantity
of
that
Liquor
had
been
before
lodg'd
:
the
longer
Pipe
was
fill'd
with
common
Water
,
and
inverted
into
a
larger
Glass
,
wherein
likewise
a
fit
proportion
of
the
same
Liquor
had
been
put
.
Then
the
Receiver
being
closely
cemented
on
to
the
Engine
,
the
Air
was
pump'd
out
for
a
pretty
while
before
the
Mercury
began
to
subside
;
but
when
it
was
so
far
withdrawn
,
that
its
Pressure
was
no
longer
able
to
keep
up
a
Mercurial
Cylinder
of
that
height
,
that
liquid
Metal
began
to
sink
;
the
Water
in
the
other
Tube
,
though
this
were
three
times
as
long
,
still
retaining
its
full
height
.
But
when
the
Quick-silver
was
fallen
so
low
,
as
to
be
but
between
three
&
four
inches
above
the
surface
of
the
Stagnant
Quick-silver
,
the
Water
also
began
to
subside
,
but
sooner
then
according
to
the
laws
of
meer
Staticks
it
ought
to
have
done
,
because
many
Aerial
Particles
emerging
from
the
body
of
the
Water
to
the
upper
part
of
the
Glass
,
did
by
their
Spring
concurr
with
the
Gravity
of
the
water
to
depress
this
Liquor
.
And
so
when
the
Quick-silver
was
three
inches
above
the
stagnant
Mercury
,
the
water
in
the
other
Pipe
was
fallen
divers
inches
beneath
42
,
and
several
inches
beneath
28
when
the
Mercury
had
subsided
an
inch
lower
.
But
this
being
no
more
then
was
to
be
expected
,
after
we
had
caus'd
the
Pumping
to
be
a
while
continued
,
to
free
the
water
the
better
from
the
latitant
Air
,
we
let
in
the
external
Air
,
and
having
thereby
impell'd
up
again
both
the
Liquors
into
their
Pipes
,
and
remov'd
the
Receiver
we
took
out
those
Pipes
,
and
inverting
each
of
them
again
to
let
out
the
Air
,
(
for
even
that
wich
held
the
Quick-silver
had
got
a
small
Bubble
,
though
inconsiderable
in
comparison
of
the
Air
that
had
got
up
out
of
the
Water
,
)
we
fill'd
each
of
them
with
a
little
of
the
restagnant
Liquor
belonging
to
it
,
and
inverting
each
Tube
once
more
into
its
proper
liquor
,
we
repeated
the
Experiment
,
and
found
it
,
as
it
seem'd
,
to
require
more
pumping
then
before
to
make
the
Liquors
begin
to
subside
;
so
that
when
the
Mercury
was
fallen
to
three
inches
,
or
two
,
or
one
,
the
water
subsided
so
near
to
the
heights
of
42
,
28
,
or
14
inches
,
that
we
saw
no
sufficient
cause
to
hinder
us
from
supposing
,
that
the
litle
differences
that
appear'd
between
the
several
heights
of
the
Quick-silver
,
and
fourteen
times
as
great
heights
of
the
Water
(
which
fell
somewhat
lower
than
its
proportion
in
Gravity
required
)
proceeded
from
some
Aerial
Corpuscles
yet
remaining
,
in
spite
of
all
we
had
done
,
in
the
water
,
and
by
their
Spring
,
though
but
faint
,
when
once
they
had
emerg'd
to
the
upper
part
of
the
Glass
,
furthering
a
little
the
depression
of
it
:
not
now
to
mention
lesser
Circumstances
,
particularly
,
that
the
surface
of
the
stagnant
Water
did
not
inconsiderably
rise
by
the
accession
of
the
Water
lately
in
the
Pipe
;
whereby
the
Cylinder
of
water
,
rais'd
above
that
surface
,
became
by
so
much
the
shorter
.
However
Your
Lordship
may
,
if
You
think
fit
,
cause
the
Experiment
to
be
reiterated
,
which
I
could
not
so
well
do
,
by
reason
of
a
mischance
that
befell
the
Receiver
.
EXPERIMENT
XV.
About
the
greatest
height
to
which
Water
can
be
rais'd
by
Attraction
or
Sucking
Pumps
.
SInce
the
making
and
the
writing
of
the
foregoing
Experiments
,
having
met
with
an
opportunity
to
borrow
a
place
somewhat
convenient
to
make
a
Tryal
to
what
height
Water
may
be
rais'd
by
Pumping
;
I
thought
not
fit
to
neglect
it
.
For
though
both
by
the
consideration
of
our
Hypothesis
,
to
whose
truth
so
many
Phaenomena
bear
witness
;
and
though
particularly
by
the
Consequences
deduceable
from
the
three
last
recited
Experiments
I
were
kept
from
doubting
what
the
event
would
be
,
yet
I
thought
it
worth
while
to
make
the
Tryal
.
I
know
what
is
said
to
have
been
the
Complaint
of
some
Pump-makers
.
But
I
confess
the
Phaenomenon
,
't
was
grounded
on
,
seem'd
not
to
me
to
be
certainly
enough
deliver'd
by
a
Writer
or
two
,
that
mention
what
they
complain'd
of
;
and
their
observation
seems
not
to
have
been
made
determinately
or
carefully
enough
for
a
matter
of
this
moment
.
Since
that
which
they
complain
of
seems
to
have
been
in
general
,
that
they
could
not
by
pumping
raise
Water
to
what
height
they
please
,
as
the
common
Opinion
of
Philosophers
about
Natures
fuga
vacui
made
them
expect
they
might
.
And
it
may
well
have
happen'd
,
that
as
they
endeavoured
onely
to
raise
it
to
the
height
their
occasions
required
,
so
all
that
their
Disappointment
manifested
,
was
,
that
they
could
not
raise
it
to
that
particular
height
:
which
did
not
determine
,
whether
if
the
Pump
had
been
a
Foot
or
a
Yard
shorter
,
the
Water
would
then
have
been
elevated
to
the
upper
part
of
it
or
no
:
but
that
which
I
chiefly
consider
is
,
that
these
being
but
Tradesmen
,
that
did
not
work
according
to
the
Dictates
of
,
or
with
design
to
satisfie
,
a
Philosophical
Curiosity
,
we
may
justly
suspect
,
that
their
Pumps
were
not
sufficiently
stanch
,
nor
the
Operation
Critically
enough
perform'd
and
taken
notice
of
.
Wherefore
,
partly
because
a
Tryal
of
such
moment
seem'd
not
to
have
yet
been
duely
made
by
any
;
and
partly
because
the
varying
weight
of
the
Atmosphere
was
not
(
that
appears
)
known
,
nor
(
consequently
)
taken
into
consideration
by
the
ingenious
Monsieur
Paschal
in
his
famous
Experiment
,
which
yet
is
but
analogous
to
this
;
and
partly
because
some
very
Late
as
well
as
Learned
Writers
have
not
acquiesc'd
in
his
Experiment
,
but
do
adhere
to
the
old
Doctrine
of
the
Schools
,
which
would
have
Water
raiseable
in
Pumps
to
any
height
,
ob
fugam
vacut
,
(
as
they
speak
,
)
I
thought
fit
to
make
the
best
shift
I
could
to
make
the
Tryal
,
of
which
I
now
proceed
to
give
Your
Lordship
an
Account
.
The
place
I
borrowed
for
this
purpose
was
a
flat
Roof
about
30
foot
high
from
the
ground
,
and
with
Railes
along
the
edges
of
it
.
The
Tube
we
made
use
of
should
have
been
of
Glass
,
if
we
could
have
procured
one
long
and
strong
enough
.
But
that
being
exceeding
difficult
,
especially
for
me
,
who
was
not
near
a
Glass-house
,
we
were
fain
to
cause
a
Tin-man
to
make
several
Pipes
of
above
an
inch
bore
,
(
for
of
a
great
length
't
was
alleadg'd
they
could
not
be
made
slenderer
,
)
and
as
long
as
he
could
,
of
Tin
or
Laton
,
as
they
call
thin
Plates
of
Iron
Tinn'd
over
;
and
these
being
very
carefully
soder'd
together
made
up
one
Pipe
,
of
about
one
or
two
and
thirty
foot
long
,
which
being
tied
to
a
Pole
we
tried
with
Water
whether
it
were
stanch
,
and
by
the
effluxions
of
that
Liquor
finding
where
the
Leaks
were
,
we
caus'd
them
to
be
stopt
with
Soder
,
and
then
for
greater
security
the
whole
Pipe
,
especially
at
the
Commissures
,
was
diligently
cas'd
over
with
our
close
black
Cement
,
upon
which
Plaister
of
Paris
was
strewed
to
keep
it
from
sticking
to
their
hands
or
cloaths
that
should
manage
the
Pipe
.
At
the
upper
part
of
which
was
very
carefully
fastned
with
the
like
Cement
a
strong
Pipe
of
Glass
,
of
between
2
and
3
foot
in
length
,
that
we
might
see
what
should
happen
at
the
top
of
the
water
.
And
to
the
upper
part
of
this
Pipe
was
(
with
Cement
,
and
by
the
means
of
a
short
elbow
of
Tin
)
very
closely
fastned
another
Pipe
of
the
same
Metal
,
consisting
of
two
pieces
,
making
a
right
Angle
with
one
another
,
whereof
the
upper
part
was
parallel
to
the
Horizon
,
and
the
other
,
which
was
parallel
to
the
Glass-pipe
,
reacht
down
to
the
Engine
,
which
was
plac'd
on
the
flat
Roof
,
and
was
to
be
with
good
Cement
sollicitously
fastned
to
the
lower
end
of
this
descending
part
of
the
Pipe
,
whose
Horizontal
leg
was
supported
by
a
piece
of
Wood
,
nail'd
to
the
above
mentioned
Rails
;
as
the
Tube
also
was
kept
from
overmuch
shaking
by
a
board
,
(
fasten'd
to
the
same
Rails
,
)
and
having
a
deep
Notch
cut
in
it
,
for
the
Tube
to
be
inserted
into
.
This
Apparatus
being
made
,
After
all
this
the
Pump
was
set
on
work
,
but
when
the
water
had
been
raised
to
a
great
height
,
and
consequently
had
a
great
Pressure
against
the
sides
of
the
Tube
,
a
small
Leak
or
two
was
either
discovered
or
made
,
which
without
moving
the
Tube
we
caus'd
to
be
well
stopt
,
by
one
that
was
sent
up
a
Ladder
to
apply
store
of
Cement
where
it
was
requisite
.
Wherefore
at
length
we
were
able
after
a
pretty
number
of
Exuctions
,
to
raise
the
Water
to
the
middle
of
the
Glass-pipe
above
mentioned
,
but
not
without
great
store
of
bubbles
,
(
made
by
the
Air
formerly
conceal'd
in
the
pores
of
the
water
,
and
now
emerging
,
)
which
for
a
pretty
while
kept
a
kind
of
Foam
upon
the
surface
of
it
,
(
fresh
ones
continually
succeeding
those
that
broke
.
)
And
finding
the
Engine
and
Tube
as
stanch
as
could
be
well
expected
,
I
thought
it
a
fit
season
to
trie
what
was
the
utmost
height
to
which
Water
could
by
Suction
be
elevated
;
and
therefore
though
the
Pump
seem'd
to
have
been
plyed
enough
already
,
yet
for
further
satisfaction
,
when
the
Water
was
within
few
inches
of
the
top
of
the
Glass
,
I
caus'd
20
Exuctions
more
to
be
nimbly
made
,
to
be
sure
that
the
water
should
be
raised
as
high
as
by
our
Pump
it
could
be
possibly
.
And
having
taken
notice
where
the
Surface
rested
,
and
caus'd
a
piece
of
Cement
to
be
stuck
near
it
,
(
for
we
could
not
then
come
to
reach
it
exactly
,
)
and
descending
to
the
Ground
where
the
stagnant
water
stood
,
we
caus'd
a
string
to
be
let
down
,
with
a
weight
hanging
at
the
end
of
it
,
which
we
applied
to
a
mark
,
that
had
been
purposely
made
at
that
part
of
the
(
Metalline
)
Tube
,
which
the
superficies
of
the
stagnant
water
had
rested
at
,
when
the
water
was
elevated
to
its
full
height
:
and
the
other
end
of
the
string
being
,
by
him
that
let
it
down
,
applied
to
that
part
of
the
Glass
,
as
near
as
he
could
guess
,
where
the
upper
part
of
the
Water
reacht
,
the
Weight
was
pull'd
up
;
and
the
length
of
the
string
,
and
(
consequently
)
the
height
of
the
Cylinder
of
Water
was
measur'd
,
which
amounted
to
33
foot
,
and
about
6
inches
.
Which
done
,
I
return'd
to
my
lodging
,
which
was
not
far
off
,
to
look
upon
the
Baroscope
,
to
be
informed
of
the
present
weight
of
the
Atmosphere
,
which
I
found
to
be
but
moderate
,
the
Quick-silver
standing
at
29
inches
,
and
between
2
and
3
eights
of
an
inch
.
This
being
taken
notice
of
,
it
was
not
difficult
to
compare
the
success
of
the
Experiment
with
our
Hypothesis
.
For
if
we
suppose
the
most
received
proportion
in
bulk
between
Cylinders
of
Quick-silver
and
of
Water
of
the
same
weight
,
namely
that
of
1
to
14
,
the
height
of
the
water
ought
to
have
been
34
foot
and
about
two
inches
,
which
is
about
8
inches
greater
than
we
found
it
.
But
then
Your
Lordship
may
be
pleased
to
remember
,
that
I
formerly
noted
(
before
ever
I
made
this
Experiment
)
that
I
did
not
allow
the
proportion
betwixt
Mercury
and
Water
(
at
least
such
water
as
I
made
my
Tryals
with
)
to
be
altogether
so
great
,
and
though
in
ordinary
Experiments
we
may
with
very
litle
inconvenience
make
use
of
that
proportion
to
avoid
fractions
,
yet
in
so
tall
a
Cylinder
of
Water
as
ours
was
,
the
difference
is
too
considerable
to
be
neglected
.
If
therefore
in
stead
of
making
an
Inch
of
Quick-silver
equivalent
to
14
inches
of
Water
,
we
abate
but
a
quarter
of
an
inch
,
which
is
but
a
56
part
of
the
height
of
the
Water
,
this
abatement
being
repeated
29
times
and
a
quarter
,
will
amount
to
7
inches
,
and
above
a
quarter
,
which
added
to
the
former
height
of
the
Water
,
namely
33
Foot
and
6
inches
,
will
make
up
34
foot
and
above
an
inch
;
so
that
the
difference
between
the
height
of
the
Mercury
sustain'd
by
the
weight
of
the
Atmosphere
in
the
Baroscope
,
and
that
of
the
Water
rais'd
and
sustain'd
by
the
Pressure
of
the
same
Atmosphere
in
the
long
Tube
did
not
appear
to
differ
more
than
an
Inch
or
two
from
the
proportion
they
ought
to
have
had
,
according
to
the
difference
of
their
specifick
Gravities
.
And
though
in
our
Experiment
the
difference
had
been
greater
,
provided
it
exceeded
not
8
or
10
Inches
,
it
would
not
have
been
strange
:
partly
,
because
of
the
difficulty
of
measuring
all
things
so
exactly
in
such
an
Experiment
,
partly
because
as
Waters
are
not
all
of
the
same
weight
,
so
a
little
disparity
of
it
in
so
long
a
Cylinder
may
be
considerable
,
and
partly
(
and
perhaps
chiefly
)
because
the
Air
flying
out
of
the
bubbles
,
that
rose
out
of
so
great
a
quantity
of
water
,
and
breaking
at
the
top
of
it
,
and
so
near
that
of
the
Tube
,
might
by
its
Spring
(
though
but
very
weak
)
assisting
the
weight
of
so
much
water
,
somewhat
(
though
not
much
)
hinder
the
utmost
elevation
of
that
Liquor
.
But
our
Experiment
did
not
make
it
needful
for
me
to
insist
on
these
considerations
,
and
the
inconsiderable
difference
that
was
betwixt
the
height
of
the
water
we
found
,
and
that
which
might
have
been
wish'd
,
did
rather
countenance
then
at
all
difavour
the
thing
to
be
made
out
by
our
Experiment
,
since
by
no
Pumping
we
could
raise
the
Water
quite
so
high
(
though
I
confess
it
wanted
but
very
little
)
as
the
weight
of
the
Atmosphere
was
able
to
keep
up
a
Cylinder
of
Mercury
proportionable
to
it
in
height
,
and
equivalent
in
weight
:
and
yet
I
presume
,
Your
Lordship
will
easily
grant
,
that
there
was
at
least
as
much
care
used
in
this
Experiment
,
to
keep
the
things
imploy'd
about
it
tight
,
as
has
been
wont
to
be
used
by
Tradesmen
in
their
Pumps
,
where
t
is
not
so
easie
either
to
prevent
a
little
insinuation
of
the
Air
,
or
to
discern
it
.
T
is
not
that
I
am
sure
,
that
even
all
our
care
would
have
kept
the
water
for
any
long
time
at
its
full
height
;
but
,
that
the
Air
was
sufficiently
exhausted
for
our
purpose
,
when
we
determin'd
the
height
of
the
water
,
I
was
induc'd
to
conclude
by
these
Circumstances
.
1.
As
well
the
construction
of
the
Engine
,
as
the
many
(
formerly
related
)
Experiments
,
that
have
been
successfully
tryed
with
it
,
shew
that
t
is
not
like
it
should
be
inferiour
in
closeness
to
the
great
Water-Pumps
,
made
by
ordinary
Tradesmen
:
and
particularly
the
XI
.
Experiment
foregoing
,
manifests
,
that
by
this
Pump
Quick-silver
was
rais'd
to
as
great
a
height
,
as
the
Atmosphere
is
able
to
support
in
the
Torricellian
Experiment
.
2.
The
stanchness
of
the
Pipe
appear'd
by
the
Diminution
(
as
to
number
)
of
Bubbles
,
that
appear'd
at
the
top
of
the
Water
,
and
by
their
size
too
,
for
when
there
was
a
leak
,
(
though
but
so
very
small
,
that
the
water
could
not
get
out
at
it
in
the
Tube
,
)
it
might
usually
be
taken
notice
of
by
the
attentive
ear
of
him
that
stood
to
watch
upon
the
Ladder
,
erected
by
the
side
of
the
Tube
;
and
the
Air
that
got
in
,
did
easily
discover
it self
to
the
Eye
by
large
Bubbles
,
manifestly
differing
from
those
that
came
from
the
Aerial
particles
belonging
to
the
water
;
and
if
the
leak
were
not
so
very
small
,
the
Air
that
got
in
would
suddenly
lift
up
the
water
above
it
,
and
perhaps
fill
with
it
the
descending
Pipe
.
3.
Though
there
had
been
some
imperceptible
Leak
,
yet
that
would
not
have
hindred
the
success
of
the
Experiment
for
the
main
.
For
in
leaks
that
have
been
but
small
,
though
manifest
enough
,
we
have
often
,
by
causing
the
Pump
to
be
ply'd
less
nimbly
then
it
now
was
,
been
able
to
prosecute
our
Tryals
;
because
the
Pump
carried
of
still
more
Air
than
could
get
in
at
a
leak
that
was
no
greater
.
4.
And
that
litle
or
no
(
intruding
)
Air
was
left
in
the
upper
part
of
our
Tube
,
was
evident
by
those
marks
,
whereby
it
was
easie
for
them
that
are
well
acquainted
with
the
Pump
,
to
estimate
what
Air
is
left
in
the
vessel
it
should
exhaust
,
and
particularly
towards
the
end
of
our
operation
I
observ'd
,
that
when
the
Sucker
was
deprest
,
there
came
out
of
the
Water
that
cover'd
the
Pump
,
so
very
few
bubbles
,
that
they
might
be
imputed
to
the
Air
afforded
by
the
Bubbles
,
springing
from
the
water
in
the
Tube
;
whereas
if
any
adventious
Air
had
got
into
that
Cylinder
of
water
,
it
would
have
appear'd
in
the
water
that
cover'd
the
Pump
.
5.
Lastly
,
it
were
very
strange
,
that
if
the
water
was
but
casually
hindred
by
some
Leak
from
ascending
any
higher
,
it
should
be
so
easy
to
raise
it
to
the
very
number
of
feet
that
our
Hypothesis
requires
,
and
yet
we
should
be
unable
by
obstinate
Pumping
to
raise
it
one
foot
higher
.
Note
,
1.
as
soon
as
we
had
made
our
Experiment
,
and
thereby
found
,
that
what
was
requisite
to
it
was
in
order
;
I
sent
to
give
notice
of
it
to
Dr
Wallis
,
and
Dr
Wren
,
as
Persons
whose
curiosity
makes
them
as
well
delighted
with
such
Tryals
,
as
their
deep
knowledg
makes
Them
most
competent
Judges
of
them
.
But
before
They
could
be
found
,
and
come
,
it
being
grown
somewhat
late
and
windy
,
I
that
was
not
very
well
,
and
had
tired
my self
with
going
up
and
down
,
could
not
stay
with
them
so
long
as
I
intended
,
but
leaving
the
rest
of
the
Repeated
Experiment
to
be
shewn
them
by
I.
M.
(
who
had
been
very
industrious
in
fitting
and
erecting
the
Tube
)
they
and
their
Learned
friend
(
whom
they
brought
with
them
)
Doctor
Millington
,
told
me
a
while
after
,
that
they
also
had
found
the
greatest
height
,
to
which
they
could
raise
the
water
,
to
be
33
foot
and
an
half
.
2.
When
the
Water
began
first
to
appear
in
the
Glass
,
the
Bubbles
would
be
,
as
I
had
foretold
,
exceeding
numerous
;
so
as
to
make
a
froath
of
near
a
foot
high
,
if
the
water
were
newly
brought
,
and
had
never
been
rais'd
in
the
Tube
before
.
But
if
the
Pumping
were
long
continued
,
the
number
and
height
(
or
at
least
one
of
the
two
)
of
the
Aggregate
of
Bubbles
,
would
(
as
there
remain'd
fewer
and
fewer
Aerial
particles
in
the
water
)
be
lesser
and
lesser
;
but
their
emerging
did
never
that
I
remember
wholly
cease
.
3.
At
the
beginning
also
there
would
appear
great
vibrations
of
the
water
in
the
upper
part
of
the
Tube
;
the
rising
and
the
falling
amounting
sometimes
to
a
foot
,
or
near
half
a
yard
:
but
these
grew
lesser
and
lesser
,
as
those
of
the
Quicksilver
in
the
Torricellian
Experiment
use
to
do
.
4.
One
may
use
an
ordinary
Pail
to
hold
the
stagnant
water
;
but
we
rather
imploy'd
a
vessel
of
Earth
made
(
for
another
purpose
)
somewhat
slender
,
and
of
a
Cylindrical
shape
,
because
in
a
narrow
vessel
t
is
more
easie
to
guess
by
the
rising
and
falling
of
the
Liquor
,
how
the
Pump
is
ply'd
,
and
to
perceive
even
smaller
Leaks
.
5.
I
must
not
forget
to
take
notice
,
that
though
the
newly
nam'd
Gentlemen
came
to
me
(
when
they
had
seen
the
Experiment
tryed
)
within
less
than
an
hour
after
the
time
I
had
look'd
upon
the
Baroscope
,
and
observ'd
the
Quick-silver
to
stand
somewhat
beneath
29
inches
,
and
3
eights
;
yet
when
presently
upon
their
return
I
consulted
the
same
instrument
again
,
the
Mercury
appear'd
to
be
sensibly
risen
,
being
somewhat
(
though
but
very
litle
)
above
9
and
20
inches
,
and
3
eights
,
and
5
or
6
hours
after
(
at
bed-time
)
I
found
it
to
be
yet
more
considerably
risen
.
Which
may
keep
Your
Lordship
from
wondring
at
what
I
intimated
a
little
above
,
touching
Monsieur
Paschal's
Experiment
,
as
well
as
touching
the
disappointment
of
the
Pump-makers
endeavours
.
For
t
is
not
onely
possible
,
that
(
as
I
have
elsewhere
noted
)
Water
may
be
raised
in
the
same
Pump
(
though
we
suppose
it
still
equally
stanch
)
higher
at
one
time
than
at
another
:
but
't
was
contingent
,
that
,
in
Monsieur
Paschal's
noble
attempt
to
imitate
the
Torricellian
Experiment
with
Water
in
stead
of
Quick-silver
,
the
proportion
betwixt
the
heights
of
those
two
Liquors
in
their
respective
Tubes
answer'd
so
well
to
their
specifick
Gravities
.
For
,
the
varying
weight
of
the
Atmosphere
being
not
then
(
that
appears
)
known
,
or
consequently
taken
into
consideration
;
if
Monsieur
Paschal
,
having
tryed
the
Torricellian
Experiment
,
when
the
Air
was
for
instance
very
heavy
,
had
tryed
his
own
Experiment
,
when
the
Atmosphere
had
been
as
light
as
I
have
often
enough
observ'd
it
to
be
,
he
might
have
found
his
Cylinder
of
Water
to
have
been
half
a
Yard
or
two
foot
shorter
than
the
formerly
measur'd
height
of
the
Quick-silver
would
have
required
.
I
have
now
no
more
to
adde
about
this
15th
Experiment
,
but
that
it
may
serve
for
a
sufficient
confirmation
of
what
I
note
in
another
Treatise
,
against
those
Hydraulical
&
Pneumatical
Writers
,
who
pretend
to
teach
wayes
of
making
Water
pass
by
inflected
Pipes
,
and
by
the
help
of
Suction
,
from
one
side
of
a
Mountain
to
the
other
,
be
the
Mountain
never
so
high
.
For
,
if
the
Water
be
to
ascend
as
't
were
spontaneously
above
35
or
36
foot
,
a
Sucking
Pump
will
not
ordinarily
,
at
least
here
in
England
,
be
able
to
raise
it
.
And
now
I
speak
of
Mountains
,
it
will
not
be
altogether
impertinent
to
add
,
that
if
it
had
not
been
for
unseasonable
weather
,
I
had
thought
fit
to
make
the
foregoing
11th
Experiment
(
of
elevating
Mercury
by
Suction
)
to
be
tryed
at
the
top
of
an
Hill
,
not
far
from
the
place
I
then
was
at
.
For
by
what
has
been
already
delivered
,
it
appears
,
that
we
might
have
estimated
the
height
,
to
which
the
Water
may
be
there
elevated
by
Suction
,
without
repeating
the
Experiment
with
a
thirty
five
foot
Tube
,
(
which
we
could
not
hope
for
conveniency
to
do
,
)
by
the
utmost
height
to
which
our
Engine
could
have
rais'd
Mercury
:
and
it
may
be
of
some
use
to
be
able
from
Experiments
to
make
some
estimate
(
for
it
can
scarce
be
an
accurate
one
)
how
much
it
may
be
expected
,
that
Pumps
shall
(
caeteris
paribus
)
loose
of
their
power
of
elevating
Water
by
Suction
,
by
being
imploy'd
at
the
top
of
an
Hill
,
in
stead
of
being
so
at
the
bottom
,
or
on
a
Plain
.
Remembring
always
what
I
lately
intimated
,
that
even
in
the
same
place
Liquors
will
be
brought
to
ascend
by
Suction
to
a
greater
or
less
height
at
one
time
than
another
,
according
to
the
varying
Gravity
of
the
Atmosphere
.
EXPERIMENT
XVI
.
About
the
bending
of
a
Springy
Body
in
the
Exhausted
Receiver
.
THe
cause
of
the
Motion
of
Restitution
in
Bodies
,
and
consequently
of
that
which
makes
some
of
them
Springy
,
which
far
the
greater
part
of
them
are
not
,
has
been
ingeniously
attempted
by
some
Modern
Corpuscularians
,
and
especially
Cartesians
;
but
since
divers
Learned
and
Judicious
men
do
still
look
upon
the
cause
of
Elasticity
,
as
a
thing
that
needs
to
be
yet
farther
enquired
into
;
and
because
I
am
not
my self
so
well
satisfied
as
to
blame
their
Curiosity
,
I
held
it
not
unfit
to
examine
by
the
help
of
our
Engine
their
Conjecture
,
who
imagine
that
the
Air
may
have
a
great
stroak
in
the
making
of
bodies
Springy
;
and
this
I
the
rather
did
,
because
I
had
[
*
](A28949-e5780-b)
*
In
Notes
about
the
history
of
Elasticity
.
elswhere
shewn
,
that
there
is
no
need
to
assert
,
that
in
all
Bodies
,
that
have
it
,
the
Elastical
power
flows
immediately
from
the
Form
,
but
that
in
divers
of
them
it
depends
upon
the
Mechanicanical
structure
of
the
Body
.
To
make
some
Tryal
therefore
,
whether
the
Air
have
any
great
Interest
in
the
Motion
of
Restitution
,
we
took
a
piece
of
Whalebone
of
a
convenient
bigness
and
length
,
and
having
fasten'd
one
end
of
it
in
a
hole
made
in
a
thick
and
heavy
Trencher
,
to
be
placed
on
the
Plate
of
the
Engine
,
we
tyed
to
the
other
end
a
Weight
,
whereby
the
Whalebone
was
moderately
bent
,
the
weight
reaching
down
so
near
to
a
Body
plac'd
in
a
level
position
under
it
,
that
if
the
Spring
were
but
a
little
weaken'd
,
the
weight
must
either
lean
upon
,
or
at
least
touch
the
Horizontal
plain
:
or
if
on
the
other
side
the
Spring
should
grow
sensibly
stronger
,
it
might
be
easily
perceiv'd
by
the
distance
of
the
weight
,
which
was
so
near
the
plain
,
that
a
litle
increase
of
it
must
be
visible
.
This
done
,
we
convey'd
these
things
into
the
Receiver
,
and
order'd
those
that
pump'd
to
shake
it
as
litle
as
they
could
,
that
the
weight
might
not
knock
against
the
Body
that
lay
under
it
,
or
so
shake
it
,
as
to
hinder
us
from
discerning
whether
or
no
it
were
depress'd
by
the
bare
withdrawing
of
the
Air.
And
when
the
Air
had
been
well
pump'd
out
,
I
watcht
attentively
whether
any
notable
Change
in
the
distance
of
the
weight
from
the
almost
contiguous
plain
would
be
produc'd
upon
its
being
let
in
again
:
for
the
weight
was
then
at
rest
,
and
the
returning
Air
flowing
in
much
more
speedily
than
it
could
before
be
drawn
out
,
I
thought
this
the
likeliest
time
to
discover
whether
the
absence
of
the
Air
had
sensibly
altered
the
Spring
of
the
Whalebone
.
But
though
the
Experiment
were
made
more
than
once
,
I
could
satisfie
my self
onely
in
this
,
that
the
depression
or
elevation
of
the
Weight
,
that
was
due
to
the
true
and
meer
change
of
the
Spring
,
was
not
very
considerable
,
since
I
did
not
think
my self
sure
,
that
I
perceiv'd
any
at
all
:
for
though
it
be
true
,
that
sometimes
,
when
the
Receiver
was
well
exhausted
,
the
Weight
seem'd
to
be
a
little
deprest
,
yet
That
I
thought
was
very
litle
,
if
any
thing
more
than
what
might
be
ascrib'd
to
the
absence
of
the
Air
,
not
consider'd
as
a
Body
that
had
any
thing
to
do
directly
with
the
Spring
,
but
as
a
Body
that
had
some
(
though
but
a
litle
)
Weight
;
upon
which
account
it
made
the
medium
,
wherein
the
Experiment
was
tried
,
contribute
to
support
the
Weight
that
bent
the
Spring
;
which
Weight
,
when
the
Air
was
absent
,
must
(
being
now
in
a
lighter
medium
)
have
its
Gravitation
increas'd
by
as
much
weight
,
as
a
quantity
of
the
exhausted
Air
,
equal
to
it
in
bulk
,
could
amount
to
.
But
this
Experiment
being
tried
only
with
VVhalebone
,
and
in
a
Receiver
not
very
Great
,
may
deserve
to
be
further
tryed
in
taller
Glasses
,
with
Springs
of
other
kinds
,
and
by
the
motions
of
a
VVatch
,
and
other
more
artificial
Contrivances
.
EXPERIMENT
XVII
.
About
the
making
of
Mercurial
,
and
other
Gages
,
whereby
to
estimate
how
the
Receiver
is
exhausted
.
BEcause
the
Air
being
invisible
,
it
is
not
always
easie
to
know
whether
it
be
sufficiently
pump'd
out
of
the
Receiver
that
was
to
be
exhausted
;
we
thought
it
would
be
very
convenient
to
have
some
Instrument
within
the
Receiver
,
that
might
serve
for
a
Gage
,
or
Standard
;
whereby
to
judge
whether
or
not
it
were
sufficiently
exhausted
.
To
this
purpose
divers
Expedients
were
thought
on
,
and
some
of
them
put
in
practise
;
which
,
though
not
equally
commodious
,
may
yet
all
of
them
be
usefully
imploy'd
,
one
on
this
occasion
,
and
another
on
that
.
The
First
(
if
I
misremember
not
)
that
I
propos'd
,
was
a
Bladder
,
(
which
may
be
greater
or
less
,
according
to
the
Size
of
the
Vessel
it
is
to
serve
for
)
to
be
very
strongly
tied
at
the
neck
,
after
having
had
onely
so
much
Air
left
in
the
folds
of
it
,
as
may
serve
to
blow
up
the
Bladder
to
its
full
dimensions
,
when
the
Receiver
is
very
well
exhausted
,
and
not
before
.
But
though
Your
Lord-ship
will
hereafter
find
that
I
yet
make
use
of
small
Bladders
on
certain
occasions
,
in
which
they
are
peculiarly
convenient
,
yet
in
many
cases
they
do
,
when
the
Glasses
are
well
exhausted
,
take
up
too
much
room
in
them
,
and
hinder
the
Objects
,
included
in
the
Receiver
,
from
being
observ'd
from
all
the
sides
of
it
.
Another
sort
of
Gage
was
made
with
Quick-silver
,
pour'd
into
a
very
short
Pipe
,
which
was
afterwards
inverted
into
a
litle
Glass
of
stagnant
Quick-silver
,
according
to
the
manner
of
the
Torricellian
Experiment
.
For
this
Pipe
being
but
a
very
few
inches
long
,
the
Mercury
in
it
would
not
begin
to
descend
,
till
a
very
Great
proportion
of
Air
was
pump'd
out
of
the
Receiver
;
because
till
then
,
the
Spring
of
the
remaining
Air
would
be
strong
enough
to
be
able
to
keep
up
so
short
a
Cylinder
of
Mercury
.
And
this
kind
of
Gage
is
no
bad
one
.
But
because
,
to
omit
some
other
litle
inconveniences
,
it
cannot
easily
be
suspended
,
(
which
in
divers
Experiments
't
is
fit
the
Gage
should
be
,
)
and
the
Mercury
in
it
is
apt
to
be
too
much
shaken
by
the
motion
of
the
Engine
,
there
was
another
kind
of
Gage
by
some
Ingenious
man
(
who
ever
he
were
)
substituted
in
its
place
,
consisting
of
a
kind
of
Siphon
,
whose
shorter
leg
hath
belonging
to
it
a
large
Bubble
of
Glass
,
most
commonly
made
use
of
at
an
Illustrious
meeting
of
Virtuosi
;
where
Your
Lordship
having
seen
it
,
I
shall
not
need
to
describe
it
more
particularly
.
But
none
of
the
Gages
I
had
formerly
us'd
,
nor
even
this
last
,
having
the
conveniences
that
some
of
my
Experiments
require
;
I
was
fain
to
devise
another
,
which
is
That
I
most
make
use
of
,
as
having
advantages
,
some
or
other
of
which
each
of
the
Gages
already
mentioned
wants
;
for
even
that
with
Spirit
of
Wine
,
not
to
mention
lesser
disadvantages
,
hath
a
Bubble
too
Great
to
let
it
be
useful
in
vessels
so
slender
,
as
for
some
purposes
I
divers
times
imploy
;
and
this
short
Cylinder
of
so
light
a
Liquor
as
spirit
of
Wine
,
makes
the
subsidence
of
the
Liquor
be
indeed
a
good
sign
that
the
Receiver
is
well
exhausted
,
but
gives
us
not
an
account
what
Quantity
of
Air
may
be
in
the
Receiver
,
'till
it
be
arriv'd
at
that
great
measure
of
Rarefaction
;
and
the
same
Liquor
,
being
upon
a
very
small
leak
(
such
as
would
not
be
prejudicial
to
many
Experiments
)
impell'd
up
to
the
top
of
the
Gage
,
we
cannot
afterwards
by
this
Instrument
take
any
measure
of
the
Air
that
gets
in
at
the
Leak
.
But
now
there
are
divers
Experiments
where
I
desire
to
see
the
Phaenomena
that
will
happen
,
not
onely
(
or
perhaps
not
at
all
)
upon
the
uttermost
Exhaustion
of
the
Air
,
but
when
the
Pressure
of
it
is
withdrawn
to
such
or
such
a
measure
,
and
also
when
the
Air
is
gradually
readmitted
.
To
make
the
Gage
we
are
speaking
of
,
take
a
very
slender
and
Cylindrical
Pipe
of
Glass
,
of
6
,
8
,
10
,
or
more
Inches
in
length
,
and
not
so
big
as
a
Goose-quill
,
This
Instrument
being
convey'd
into
a
Receiver
,
(
which
for
expedition
sake
we
choose
as
small
as
will
serve
the
turn
,
)
the
Air
is
to
be
very
diligently
pump'd
out
,
and
then
notice
is
to
be
taken
to
what
part
of
the
Gage
the
Mercury
is
deprest
,
that
we
may
know
,
when
we
shall
afterwards
see
the
Mercury
driven
so
far
,
that
the
Receiver
,
the
Gage
is
plac'd
in
,
is
well
exhausted
.
And
if
it
be
much
desired
to
know
more
accurately
(
for
one
may
arrive
pretty
near
the
truth
by
Guess
)
what
stations
of
the
Mercury
in
the
Gage
are
answerable
to
the
degrees
of
the
Rarefaction
of
the
Air
in
the
Receiver
;
that
may
be
compassed
either
by
Calculation
,
(
which
is
not
so
easie
,
and
supposes
some
Hypotheses
,
)
or
(
though
not
without
some
trouble
)
by
letting
in
the
water
as
often
as
is
necessary
,
into
a
Receiver
,
whose
intire
capacity
is
first
measured
,
and
in
which
there
may
be
Marks
made
to
shew
when
the
water
to
be
let
in
shall
fill
a
fourth
part
,
or
half
,
or
three
quarters
&c.
of
the
Cavity
.
For
if
(
for
instance
)
when
the
Quick-silver
in
the
Gage
is
deprest
to
such
a
Mark
,
you
let
in
the
water
,
and
that
Liquor
appears
to
fill
a
fourth
part
of
the
Receiver
,
you
may
conclude
,
that
about
a
4th
part
of
the
Air
was
pump'd
out
,
or
that
a
4th
part
of
the
Spring
,
that
the
whole
included
Air
had
,
was
lost
by
the
Exhaustion
,
when
the
Quick
silver
in
the
Gage
was
at
the
Mark
above
mentioned
;
&
if
the
admitted
water
do
considerably
either
fall
short
of
,
or
exceed
the
quantity
you
expected
,
you
may
the
next
time
let
in
the
water
either
after
the
Mercury
has
a
litle
past
the
former
Mark
,
or
a
litle
before
it
is
arriv'd
at
it
.
And
when
once
you
have
this
way
obtain'd
one
pretty
long
and
accurate
Gage
,
you
will
not
need
to
take
so
much
pains
to
make
others
,
since
you
may
divide
them
by
the
help
of
that
one
;
for
this
being
plac'd
with
any
other
in
a
small
Receiver
,
when
the
Mercury
in
the
Standard-Gage
(
if
I
may
so
call
it
)
is
deprest
to
any
of
the
determinate
divisions
obtain'd
by
observation
,
you
may
thence
conclude
how
much
the
Air
in
the
Receiver
is
rarefied
,
and
consequently
by
taking
notice
of
the
place
where
the
Mercury
rests
in
the
other
Gage
,
you
may
determine
what
degree
of
Exhaustion
in
a
Receiver
is
denoted
by
that
station
of
the
Mercury
in
this
Gage
.
Perhaps
I
need
not
tell
your
Lordship
that
the
Ground
of
this
contrivance
was
,
that
whereas
in
divers
other
Gages
,
when
the
Pump
came
to
be
obstinately
ply'd
,
the
Expansion
of
the
included
Air
would
be
so
great
,
that
it
would
either
drive
out
the
Liquor
,
especially
if
it
were
light
,
or
in
part
make
an
escape
through
it
:
I
judg'd
that
in
such
an
Instrument
,
as
that
newly
describ'd
,
those
inconveniences
would
be
avoided
,
because
that
the
more
the
Air
should
come
to
be
dilated
,
the
greater
weight
of
Quick-silver
it
would
in
the
shorter
Leg
have
to
raise
,
which
would
sufficiently
hinder
it
from
making
that
heavy
liquor
run
over
;
and
the
same
ponderousness
of
the
Liquor
,
together
with
the
slenderness
of
the
Pipe
,
would
likewise
hinder
the
included
Air
from
getting
through
in
Bubbles
.
NB.
1.
For
most
Experiments
,
where
exact
measures
are
not
required
,
it
will
not
be
so
necessary
to
mark
the
Gage
at
any
other
station
of
the
Quick-silver
then
that
which
t
is
brought
to
by
the
Exhaustion
of
the
Receiver
,
for
by
that
alone
we
may
know
when
the
Air
is
well
pump'd
out
of
the
Receiver
,
wherein
the
Gage
is
included
:
and
when
one
is
a
litle
us'd
to
some
particular
Gage
,
one
may
by
the
subsidence
of
the
Mercury
guess
at
the
degree
of
the
Airs
rarefaction
,
so
near
as
may
serve
the
turn
in
such
Experiments
.
But
when
this
Instrument
is
to
be
us'd
about
nice
Tryals
,
where
it
may
be
thought
requisite
to
have
it
divided
according
to
one
of
the
ways
formerly
proposed
,
it
will
on
divers
occasions
be
more
secure
(
in
case
the
maker
of
the
Gage
has
skill
to
do
it
,
)
to
put
to
the
Divisions
rather
by
litle
Knubs
of
Glass
,
than
by
Paper
;
because
this
will
on
such
occasions
be
in
danger
either
to
be
rubb'd
off
,
or
wetted
.
And
if
Glass-marks
be
us'd
,
it
will
be
convenient
that
every
fifth
,
or
tenth
,
or
such
Ordinal
number
as
shall
be
judg'd
fit
,
be
made
of
Glass
of
a
differing
colour
,
for
distinction
sake
,
&
the
more
easie
reckoning
.
We
sometimes
for
a
need
apply
,
in
stead
of
these
Glass-knubs
,
little
marks
of
hard
sealing
Wax
,
which
will
not
be
injur'd
by
moisture
,
as
those
Papers
will
that
are
pasted
on
;
but
these
of
Wax
,
though
in
many
cases
useful
,
are
not
comparable
to
the
other
in
all
,
since
if
they
be
very
small
,
they
are
easily
rubb'd
off
,
and
if
large
,
they
make
not
the
Division
exact
enough
,
and
often
hide
the
true
place
of
the
Quick-silver
.
I
shall
here
about
the
Mercurial
Gages
add
onely
this
Hint
,
that
what
I
propos'd
to
my self
in
that
Contrivance
,
was
not
onely
to
estimate
the
Air
pump'd
out
of
the
Receiver
,
or
that
remaining
in
it
;
but
also
,
by
the
help
of
this
Instrument
(
as
elsewhere
by
another
Experiment
)
to
measure
(
somewhat
near
)
the
strength
of
the
Spring
of
rarefied
Air
,
according
to
its
several
degrees
of
Rarefaction
;
and
by
this
Observation
,
in
concurrence
with
other
things
,
I
hoped
we
might
(
according
to
what
I
have
elsewhere
insinuated
)
be
assisted
to
estimate
,
by
the
Cylinder
of
Mercury
rais'd
in
the
open
leg
,
the
Expansion
of
the
Air
included
in
the
sealed
leg
:
but
of
these
things
I
design'd
in
this
place
to
give
but
an
Intimation
.
3.
That
leg
of
the
Gage
that
includes
the
Air
,
may
be
seal'd
up
either
at
the
beginning
,
before
the
Pipe
be
bent
into
a
Syphon
,
or
(
which
is
much
better
)
after
the
following
manner
.
Before
you
bend
the
Pipe
,
draw
out
the
end
of
it
,
which
you
mean
to
seal
,
to
a
short
and
very
slender
Thread
;
then
having
made
the
Pipe
a
Siphon
,
pour
into
the
leg
,
which
is
to
remain
open
,
as
much
Quick-silver
as
you
shall
judg
convenient
,
which
will
rise
to
an
equal
height
in
the
other
leg
;
out
of
which
by
gently
inclining
the
Siphon
,
you
may
pour
out
the
superfluous
Mercury
,
(
if
there
be
any
,
)
and
when
you
see
that
there
is
an
inch
,
or
half
an
inch
(
or
what
part
you
design'd
to
leave
for
Air
)
unfill'd
with
Mercury
,
next
to
the
end
that
is
to
be
clos'd
;
and
that
the
rest
of
that
leg
,
and
as
much
(
as
you
think
fit
)
of
the
other
is
full
of
Quick-silver
,
you
may
,
by
keeping
the
Siphon
in
the
same
posture
,
and
warily
applying
the
slender
Apex
above
mentioned
to
the
upper
part
of
the
flame
of
a
Lamp
,
blown
Horizontal
,
easily
seal
up
that
Apex
without
cracking
,
or
prejudicing
the
open
leg
,
or
considerably
injuring
the
Air
hole
,
that
was
to
be
seal'd
up
in
the
other
.
And
this
sealing
of
one
leg
must
(
as
t
is
evident
)
keep
the
Mercury
suspended
in
it
,
though
it
be
higher
by
divers
inches
than
that
in
the
open
leg
,
till
the
withdrawing
of
the
external
Air
enable
the
included
,
by
expanding
it self
to
depress
the
Mercury
in
the
seal'd
leg
,
and
raise
it
in
the
open
.
4.
How
the
length
of
these
Mercurial
Gages
is
to
be
varied
,
according
to
the
Bigness
and
Shape
of
the
slender
Receivers
they
are
to
be
imploy'd
in
,
and
how
they
may
easily
be
made
either
to
stand
upright
at
the
bottom
of
the
Receiver
,
or
be
kept
hanging
in
the
middle
,
or
near
the
top
of
it
(
as
occasion
may
require
,
)
and
how
the
open
end
may
be
made
to
secure
the
Mercury
,
in
cases
where
that
is
needful
,
belongs
not
so
properly
to
this
Treatise
,
as
to
the
Second
part
of
the
Continuation
;
where
,
if
ever
I
trouble
Your
Lordship
with
it
,
the
Usefulness
of
this
sort
of
Gages
,
and
the
Circumstances
that
may
advantage
them
,
will
best
appear
.
5.
There
being
some
Experiments
,
wherein
it
is
not
desir'd
that
the
Receiver
should
be
neer
exhausted
,
but
rather
that
the
degrees
of
the
Airs
rarefaction
,
which
ought
not
to
be
very
great
,
should
be
well
measur'd
;
we
may
in
such
cases
make
use
of
Gages
shap'd
like
those
hitherto
describ'd
,
but
made
as
long
as
the
Receiver
will
well
admit
,
and
furnish'd
in
stead
of
Quick-silver
either
with
spirit
of
Wine
coloured
with
Cocheneel
,
or
else
with
the
tincture
of
red
Rose-leaves
,
drawn
onely
with
common
Water
,
made
shap
by
a
litle
either
of
the
Oyl
,
or
the
spirit
of
Vitriol
,
or
of
common
Salt
.
For
the
lightness
of
these
Liquors
in
comparison
of
Quick-silver
will
allow
the
Expansins
of
the
Air
included
in
the
Gage
to
be
very
manifest
,
and
notable
enough
,
though
not
half
,
or
perhaps
a
quarter
of
the
Air
be
pump'd
out
of
the
Receiver
.
6.
You
may
also
in
such
cases
as
these
,
where
the
Receiver
is
large
enough
,
and
is
not
to
be
quite
exhausted
,
make
use
of
a
Mercurial
Gage
,
differing
from
those
above
describ'd
onely
in
this
,
that
the
shorter
leg
need
not
be
above
an
inch
,
or
half
an
inch
long
,
before
it
expand
it self
into
a
Bubble
of
about
half
an
inch
,
or
an
inch
in
Diameter
;
and
having
at
the
upper
part
a
very
short
and
slender
unseal'd
Pipe
,
at
which
the
Air
may
get
in
and
out
:
by
which
Contrivance
you
may
have
this
Convenience
,
that
You
need
not
include
so
much
Air
,
as
otherwise
would
be
requisite
,
at
the
top
of
the
longer
Leg
,
because
the
Mercury
in
the
shorter
cannot
,
by
reason
of
the
breadth
of
the
Bubble
,
whereinto
the
Expansion
of
the
Air
drives
it
,
be
considerably
rais'd
:
Upon
which
account
it
becomes
more
easie
to
estimate
by
the
Eye
the
degrees
of
the
included
Airs
Rarefaction
,
which
may
be
done
almost
as
easily
,
as
if
there
were
water
in
stead
of
Mercury
:
provided
it
be
remembred
,
that
Quick-silver
by
reason
of
its
ponderousness
,
does
far
more
assist
the
dilatation
of
the
Air
,
then
so
much
Water
would
do
.
EXPERIMENT
XVIII
.
About
an
easie
way
to
make
the
Pressure
of
the
Air
sensible
to
the
Touch
of
those
that
doubt
of
it
.
THough
several
of
our
Experiments
sufficiently
manifest
to
the
Skilful
,
that
the
Pressure
of
the
Air
is
very
considerable
;
yet
because
some
of
them
require
peculiar
Glasses
,
and
other
Instruments
,
which
are
not
always
at
hand
,
and
because
there
are
many
that
think
it
surer
to
estimate
the
force
of
Pressure
by
what
they
immediately
feel
,
than
by
any
other
way
;
I
was
invited
for
the
sake
of
such
to
imploy
an
easie
Experiment
,
which
usually
proved
convincing
,
because
it
operated
on
that
Sense
,
whereon
they
chiefly
rely'd
.
I
caus'd
then
to
be
made
a
hollow
(
but
strong
)
piece
of
Brass
,
not
above
two
or
three
inches
high
,
(
that
it
might
be
in
a
trice
exhausted
,
)
and
open
at
both
ends
,
whose
Orifices
were
Circular
and
parallel
,
but
not
equal
,
(
the
Instrument
being
made
tapering
,
so
that
it
might
be
represented
by
an
excavated
Conus
truncatus
,
or
a
Gigg
,
with
the
lower
part
cut
transversly
off
.
)
This
piece
of
Brass
being
cemented
on
,
as
if
it
were
a
small
Receiver
to
the
Engine
,
the
Person
,
that
would
not
believe
the
Pressure
of
the
Air
to
be
near
so
considerable
as
was
represented
,
was
bidden
to
lay
the
Palm
of
his
Hand
upon
the
upper
Orifice
;
and
being
ordered
to
lean
a
little
upon
it
,
that
so
the
lower
part
of
his
hand
might
prove
a
close
Cover
to
the
Orifice
,
one
Exuction
of
the
Air
was
made
by
the
help
of
the
Pump
:
and
then
upon
the
withdrawing
of
the
greatest
part
of
the
Pressure
of
the
internal
Air
,
that
before
counterballanc'd
that
of
the
External
,
the
Hand
being
left
alone
to
support
the
weight
of
the
Ambient
Air
,
would
be
pressed
inwards
so
forceably
,
that
though
the
stronger
sort
of
men
were
able
(
though
not
without
much
adoe
)
to
take
off
their
Hands
,
yet
the
weaker
sort
of
Tryers
could
not
do
it
,
(
especially
if
by
a
second
Suck
the
litle
Receiver
were
better
exhausted
,
)
but
were
fain
to
stay
for
the
Return
of
the
Air
into
the
Receiver
to
assist
them
.
This
Experiment
being
design'd
rather
to
convince
than
to
punish
those
that
were
to
make
it
,
we
took
care
not
onely
that
the
Brass
should
be
so
thick
,
and
the
Orifices
so
smooth
,
that
no
Sharpness
nor
Roughness
of
the
Metal
should
offend
the
Hand
;
but
also
that
the
narrower
Orifice
(
which
was
the
oftenest
made
use
of
)
should
be
but
about
an
inch
and
a
quarter
in
Diameter
.
But
if
any
were
desirous
of
a
more
sensible
conviction
,
't
was
very
easie
to
give
it
him
by
making
the
larger
Orifice
the
uppermost
,
which
was
the
reason
why
the
Instrument
was
,
as
we
formerly
noted
,
made
tapering
.
But
yet
this
larger
Orifice
ought
not
to
exceed
2
Inches
,
or
2
Inches
and
1/2
in
wideness
,
least
the
great
Weight
of
the
Air
endanger
the
breaking
or
considerably
hurting
the
Hand
of
the
Experimenter
.
Which
Caution
I
am
put
in
mind
of
giving
,
by
remembring
that
I
once
much
endangered
my
own
Hand
,
through
the
mistake
of
him
that
manag'd
the
Pump
,
who
unawares
to
me
set
it
on
work
,
when
,
for
another
purpose
,
I
had
laid
my
Hand
upon
the
Orifice
of
an
Instrument
of
too
great
a
Diameter
.
THe
famous
Experiment
of
Torricellius
,
mentioned
in
the
17th
of
our
already
published
Tryals
,
is
of
that
Noblenesse
and
Importance
,
that
though
divers
Learned
men
have
(
but
upon
very
differing
principles
)
discours'd
of
it
in
Print
,
which
gives
me
the
lesse
mind
to
insist
long
upon
it
here
,
yet
I
shall
not
scruple
to
subjoin
some
Notes
concerning
Tryals
that
I
made
,
(
though
for
want
of
opportunity
I
could
not
repeat
them
according
to
my
custom
,
)
which
I
had
not
met
with
in
Others
,
and
which
may
serve
to
confirm
the
Hypothesis
made
use
of
in
this
Continuation
,
and
the
Treatise
it
belongs
to
.
EXPERIMENT
XIX
.
About
the
Subsidence
of
Mercury
in
the
Tube
of
the
Torricellian
Experiment
to
the
level
of
the
stagnant
Mercury
.
A
Baroscope
being
included
in
a
Receiver
,
made
of
a
long
Bolt
head
with
the
lower
part
of
the
Ball
cut
Circularly
off
,
upon
the
first
Exuction
of
the
Air
,
the
Quick-silver
that
before
stood
at
29
inches
,
(
the
Atmosphere
appearing
then
by
a
constant
Baroscope
very
light
,
)
would
fall
so
low
as
to
rest
at
9
or
10
inches
,
(
for
once
I
measur'd
the
Subsidence
beneath
its
former
Elevation
,
)
and
in
about
three
Sucks
more
it
would
be
brought
quite
down
to
the
Level
of
the
Stagnant
Quick-silver
,
and
somewhat
below
,
(
as
t
is
the
property
of
Quick-silver
,
quite
contrary
to
Water
,
to
rise
less
in
a
slender
Pipe
than
in
a
wide
.
)
The
Air
being
let
into
the
Receiver
,
the
Quick-silver
would
be
impell'd
up
slowlier
or
faster
,
as
we
pleas'd
,
to
the
former
height
of
29
inches
,
or
thereabouts
.
NB.
1.
That
if
the
Air
were
suffer'd
to
go
hastily
out
of
the
Receiver
,
the
Mercury
would
,
by
virtue
of
the
accelerated
motion
acquir'd
in
its
descent
,
at
the
very
first
Suck
descend
till
it
reacht
within
an
inch
or
two
of
the
stagnant
Mercury
,
though
it
would
presently
after
a
few
risings
and
fallings
settle
at
the
height
of
9
or
10
inches
,
till
the
next
Suck
brought
it
down
lower
.
2.
If
when
the
Mercury
was
reimpell'd
up
to
its
due
height
,
those
that
manag'd
the
Pump
did
,
in
stead
of
rarifying
the
Air
,
a
little
compress
it
,
the
Quick-silver
would
by
the
compress'd
Air
be
easily
made
to
rise
an
inch
or
more
above
the
former
standard
of
29
inches
.
Which
Circumstance
I
mention
,
not
as
a
new
thing
,
but
to
confirm
(
what
some
think
strange
)
a
Passage
printed
,
page
the
59th
,
where
I
mention
,
that
if
the
Air
in
the
Receiver
,
in
stead
of
being
rarify'd
in
the
Engine
,
were
a
litle
comprest
by
it
;
the
Pressure
of
the
included
Air
,
being
somewhat
increas'd
by
having
its
Spring
thus
bent
,
would
sustain
the
Mercury
in
the
Torricellian
Tube
at
a
greater
than
the
wonted
Height
.
And
to
confirm
another
passage
in
the
same
Page
,
where
I
observ'd
,
that
if
the
Pressure
of
the
Air
upon
the
stagnant
Mercury
be
not
so
great
as
t
is
wont
to
be
,
the
Mercury
will
begin
to
subside
in
a
(
fill'd
and
inverted
)
Tube
,
which
wants
of
the
usual
height
;
we
took
a
Glass
Cane
,
(
seal'd
at
one
end
,
)
much
shorter
than
the
due
length
,
and
having
fill'd
it
with
Mercury
,
and
inverted
it
into
a
Glass
full
of
stagnant
Mercury
,
we
placed
all
in
the
former
Receiver
;
where
the
Mercurial
Cylinder
for
want
of
the
requisite
height
remain'd
totally
suspended
,
but
upon
the
first
or
second
Suck
it
would
subside
,
and
in
two
or
three
Sucks
more
it
would
fall
to
the
levell
of
the
stagnant
Mercury
,
or
a
little
below
it
.
Upon
the
letting
in
of
the
Air
it
would
be
impell'd
to
the
very
Top
of
the
Tube
,
bating
an
Aerial
bubble
,
which
seem'd
to
come
from
the
Mercury
it self
,
and
was
so
little
,
as
not
to
be
at
all
discernable
,
save
to
a
very
attentive
Eye
.
This
Experiment
I
should
not
think
fit
here
to
relate
,
EXPERIMENT
XX.
Shewing
that
in
Tubes
open
at
both
ends
,
when
no
fuga
Vacui
can
be
pretended
,
the
weight
of
Water
will
raise
Quick-silver
no
higher
in
slender
than
in
larger
Pipes
.
BEcause
I
find
it
,
even
by
Learned
and
very
Late
Writers
,
urg'd
as
a
clear
and
cogent
Argument
against
those
that
ascribe
the
Phaenomena
of
the
Torricellian
Experiment
to
the
weight
of
the
External
Air
;
That
t
is
impossible
,
that
the
Air
,
though
't
were
granted
to
be
a
heavy
Body
,
could
sustain
the
Quick-silver
at
the
same
height
in
Tubes
of
very
differing
bigness
,
since
the
same
Air
cannot
equally
counterpoise
Mercurial
Cylinders
of
such
unequal
weights
;
and
because
this
Objection
is
wont
very
much
to
puzzle
those
that
are
not
well
acquainted
with
the
Hydrostaticks
,
I
presume
Your
Lordship
will
allow
me
,
till
I
can
shew
you
some
Hydrostatical
Papers
,
by
which
the
Objection
may
appear
to
be
but
ill
grounded
upon
the
true
Theoremes
of
that
Art
,
to
annex
the
Transcripts
of
a
couple
of
Expeperiments
,
(
that
I
once
made
to
remove
this
,
supposedly
insuperable
,
Difficulty
,
)
just
as
I
find
them
registred
in
my
Note-books
.
The
I.
Tryal
.
Sept.
the
2.
1662.
We
took
a
very
large
Glass-Tube
,
Hermetically
seal'd
at
one
end
,
and
about
two
Foot
and
a
half
in
Length
.
Into
this
we
poured
Quick-silver
to
the
height
of
3
or
4
fingers
.
Then
we
took
a
couple
of
Cylindrical
Pipes
of
very
unequal
sizes
,
(
the
wider
being
as
big
agen
as
the
slenderer
)
and
open
at
both
Ends.
The
lower
Ends
of
these
two
Pipes
we
thrust
into
the
Quick-silver
,
and
fasten'd
them
near
their
upper
Ends
to
the
Tube
with
strings
,
that
they
might
not
be
lifted
up
,
nor
mov'd
out
of
their
posture
,
in
which
the
convex
Surface
of
the
Mercury
in
both
the
Pipes
seem'd
to
lie
almost
in
a
Level
,
the
Tube
also
it self
being
plac'd
upright
in
a
Frame
.
This
done
,
by
the
help
of
a
Funnel
we
poured
in
Water
by
degrees
at
the
top
of
the
Tube
,
and
observ'd
,
that
as
the
Water
gravitated
more
and
more
upon
the
stagnant
Mercury
,
so
the
included
Mercury
rose
equally
in
both
the
Pipes
,
till
the
Tube
being
almost
fill'd
with
Water
,
the
Mercury
appeared
to
be
impell'd
up
to
and
sustain'd
at
as
great
a
height
in
the
Big
Tube
,
as
in
the
Lesser
,
being
in
either
raised
about
two
Inches
above
the
Surface
of
the
Stagnant
Quick-silver
.
NB.
1.
Having
caus'd
about
half
the
Water
(
having
no
conveniency
to
withdraw
any
more
)
in
the
Tube
to
be
suck'd
out
at
the
Top
,
we
observ'd
the
Quick-silver
in
both
the
Tubes
to
subside
uniformly
,
and
to
reascend
alike
upon
the
reaffusion
of
the
Water
.
2.
We
endeavoured
to
try
the
Experiment
(
for
their
sake
who
have
not
the
Conveniency
to
have
such
Tubes
purposely
made
)
in
a
wooden
vessel
,
into
which
,
when
it
was
fill'd
with
water
,
we
let
down
a
flat
Glass
furnisht
with
stagnant
Mercury
,
whereinto
the
Ends
of
the
two
Pipes
were
immers'd
.
But
the
Opaeousness
of
the
Cylinder
(
which
reduced
us
to
see
onely
from
the
Top
the
Reflection
of
the
stagnant
Mercury
,
)
and
other
Impediments
,
disabled
us
to
perceive
the
Motions
and
Stations
of
the
Mercury
in
the
Pipes
,
though
we
once
made
use
of
a
Candle
the
better
to
discern
them
.
The
II.
Tryal
.
We
took
a
very
wide
Tube
of
Glass
,
of
about
a
Foot
long
,
and
into
it
poured
a
convenient
Quantity
of
Quick-silver
.
We
took
also
two
Pipes
of
about
equal
length
,
and
of
that
disparity
in
Bigness
that
we
newly
mentioned
,
(
those
Pipes
lately
described
being
indeed
cut
off
from
these
we
are
now
to
speak
of
,
)
and
these
being
fill'd
with
Quick-silver
(
after
the
manner
of
the
Torricellian
Experiment
)
were
by
a
certain
Contrivance
let
down
into
the
Tube
,
and
unstopt
under
the
Surface
of
the
stagnant
Mercury
,
and
then
the
Quick-silver
in
the
Pipes
falling
down
to
its
wonted
Station
,
and
resting
there
,
we
poured
into
the
Tube
about
a
foot
height
(
by
Guess
)
of
Water
,
whereupon
the
Quick-silver
as
it
before
stood
,
as
it
were
,
in
a
Level
in
both
the
Pipes
,
so
it
was
,
for
ought
appear'd
to
us
,
equally
impell'd
up
beyond
its
wonted
Station
,
and
sustain'd
there
both
in
the
slender
and
in
the
bigger
Pipe
,
and
upon
the
withdrawing
of
some
of
the
Water
it
began
to
subside
alike
,
as
to
sense
,
in
them
both
,
falling
no
lower
in
the
bigger
than
in
the
slenderer
.
And
Water
being
a
second
time
poured
down
into
the
Tube
,
the
Mercury
did
in
both
Pipes
rise
uniformly
as
before
.
By
which
and
the
former
Experiment
it
sufficiently
appeared
,
that
a
Gravitating
Liquor
as
Air
or
Water
,
may
impell
or
keep
up
Mercury
to
the
same
height
in
Tubes
that
are
of
very
differing
Capacities
:
And
that
Liquors
ballance
each
other
according
to
their
Altitude
,
and
not
barely
according
to
their
Weight
.
For
in
this
last
Experiment
,
the
Additional
Cylinder
of
one
Inch
of
Mercury
was
manifestly
rais'd
and
kept
up
by
the
Water
incumbent
on
the
stagnant
Mercury
,
(
the
other
Cause
,
whatever
it
were
,
of
the
Mercury's
Suspension
,
being
able
to
sustain
but
a
Cylinder
shorter
by
an
Inch.
)
And
the
same
parcel
of
Water
did
counterpoise
in
the
differing
Pipes
two
Mercurial
Cylinders
,
which
though
but
of
the
same
Altitude
,
(
namely
about
an
Inch
)
were
of
very
unequal
Weight
.
EXPERIMENT
XXI
.
Of
the
Heights
at
which
pure
Mercury
,
and
Mercury
Amalgam'd
with
Tin
,
will
stand
in
Barometers
.
COnsidering
with
my self
,
that
if
the
Sustentation
of
the
Quick-silver
in
the
Torricellian
Experiment
at
a
certain
height
,
depends
upon
the
Aequilibrium
,
which
a
Liquor
of
that
Specifick
Gravity
does
at
such
a
height
attain
to
with
the
External
Air
,
if
that
peculiar
and
determinate
Gravity
of
the
Quick-silver
be
altered
,
the
height
of
it
,
requisite
to
an
Aequilibrium
with
the
Atmosphere
,
must
be
altered
too
:
(
Considering
this
I
say
)
I
thought
it
might
somewhat
confirm
the
Hypothesis
hitherto
made
use
of
,
if
a
Phaenomenon
so
agreeable
to
it
were
actually
exhibited
.
This
I
supposed
performable
two
differing
wayes
,
namely
by
mixing
or
(
as
Chymists
speak
)
Amalgamating
Mercury
either
with
Gold
,
to
make
it
a
mixture
more
heavy
,
or
with
some
other
Metal
that
might
make
it
more
light
than
Mercury
alone
is
.
But
the
former
of
those
two
ways
I
forbore
to
prosecute
being
where
I
then
was
unfurnished
with
a
sufficient
quantity
of
refined
Gold
,
(
for
that
which
is
Coyn'd
is
generally
allayed
with
Silver
,
or
Copper
,
or
both
,
)
and
therefore
Amalgamating
Mercury
with
a
convenient
proportion
of
pure
Tin
,
(
or
,
as
the
Tradesmen
call
it
,
Block-Tin
,
)
that
the
mixture
might
not
be
too
thick
to
be
readily
poured
out
into
a
Glass-Tube
,
and
to
subside
in
it
,
we
fill'd
with
this
Amalgam
a
Cylindrical
Pipe
,
sealed
at
one
end
,
and
of
a
fit
length
,
and
then
inverted
it
into
a
litle
Glass
furnished
with
the
like
mixture
.
Of
which
Tryal
the
Event
was
,
that
the
Amalgam
did
not
fall
down
to
29
,
nor
even
to
30
inches
,
but
stopt
at
31
above
the
surface
of
the
stagnant
Mixture
.
Note
1.
That
though
one
may
expect
,
that
the
Event
of
the
Experiment
would
be
the
more
considerable
,
the
Greater
the
Quantity
is
that
is
mingled
of
the
light
Metal
,
yet
care
must
be
taken
that
the
Amalgam
be
not
made
too
thick
,
least
part
of
it
stick
here
and
there
(
as
we
did
to
our
trouble
find
it
apt
to
do
)
to
the
inside
of
the
Pipe
,
by
which
means
some
Aerial
Corpuscles
will
meet
with
such
convenient
Receptacles
,
as
to
make
it
very
difficult
,
if
not
almost
impossible
,
to
free
the
Tube
quite
from
Air.
2.
It
may
perhaps
be
worth
while
to
try
,
whether
by
comparing
the
height
of
the
Amalgam
,
to
what
it
ought
to
be
upon
the
score
of
the
specifick
Gravities
of
the
Mercury
,
and
the
Tin
,
mingled
in
a
known
Proportion
in
the
Amalgam
,
any
discovery
may
be
made
whether
those
two
Metals
do
penetrate
one
another
after
such
a
manner
(
for
there
is
no
strict
Penetration
of
Dimensions
among
Bodies
)
as
Copper
and
Tin
have
,
as
I
elsewhere
note
,
been
(
by
some
Chymists
)
observ'd
to
do
,
when
being
melted
down
together
they
make
up
a
more
close
and
specifically
ponderous
Body
,
than
their
respective
Weights
seem'd
to
require
.
3.
That
by
comparing
this
21.
Experiment
with
the
18th
of
those
formerly
published
,
it
may
appear
,
that
the
height
of
the
Liquor
,
suspended
in
the
Torricellian
Experiment
,
depends
so
much
upon
its
aequilibrium
with
the
outward
Air
,
that
it
may
be
varied
by
a
change
of
Gravity
in
either
of
the
two
Bodies
that
counterballance
each
other
,
whether
the
change
be
of
weight
in
the
Atmosphere
,
or
of
Specifick
Gravity
in
the
suspended
Liquor
.
Advertisement
.
I
Should
here
acquaint
Your
Lordship
with
what
I
have
since
tried
in
reference
to
the
18th
of
the
Printed
Experiments
,
where
I
mention
,
that
I
observed
,
by
long
keeping
the
same
Instrument
with
which
I
once
made
the
Torricellian
Experiment
in
the
same
place
,
that
the
height
of
the
suspended
Mercury
would
vary
according
as
the
weight
of
the
Atmosphere
hapned
to
change
.
But
though
about
the
Barometer
(
as
others
have
by
their
imitation
allowed
me
to
call
the
Instrument
hitherto
mentioned
,
put
into
a
Frame
)
I
made
in
the
year
1660
several
Observations
,
that
would
not
perhaps
be
impertinent
in
this
place
,
yet
having
long
since
left
them
with
a
Friend
,
who
lives
far
off
,
and
not
having
them
now
in
my
power
,
I
must
beg
Your
Lordships
permission
to
reserve
them
for
a
part
of
the
Appendix
,
which
I
doubt
I
shall
be
engaged
to
adde
to
this
Epistle
.
And
in
the
mean
time
I
shall
not
forbear
to
present
Your
Lordship
those
other
Papers
that
I
have
by
me
,
relating
to
the
Barometer
;
some
of
which
will
,
I
presume
,
sufficiently
confirm
my
lately
mentioned
conjecture
about
the
cause
of
the
Variation
observed
in
the
Height
of
the
suspended
Mercury
.
EXPERIMENT
XXII
.
Wherein
is
propos'd
a
way
of
making
Barometers
,
that
may
be
transported
even
to
distant
Countries
.
THinking
it
a
desireable
thing
(
as
I
have
elsewhere
intimated
)
to
be
able
to
compare
together
,
by
the
help
of
Barometers
,
the
weight
of
the
Atmosphere
at
the
same
time
,
not
onely
in
differing
parts
of
the
same
Country
,
as
of
England
,
but
in
differing
Regions
of
the
World
;
I
could
not
but
foresee
that
't
would
be
very
difficult
to
accomplish
my
desire
without
altering
the
form
of
the
Barometers
I
had
hitherto
made
use
of
.
For
as
these
be
unfit
to
be
transported
far
,
because
that
stagnant
Mercury
would
be
so
apt
to
spill
.
So
the
procuring
them
to
be
made
in
the
places
where
they
are
to
be
used
,
though
it
be
no
bad
expedient
,
and
such
as
I
have
divers
times
made
use
of
,
is
liable
to
this
inconvenience
;
that
,
besides
that
few
will
take
the
pains
,
and
have
the
skill
,
requisite
to
make
Baroscopes
well
,
though
they
be
sufficiently
furnished
with
Glasses
and
Mercury
for
that
purpose
,
besides
this
,
I
say
,
except
men
be
more
than
ordinarily
diligent
and
skilful
,
(
and
perhaps
though
they
be
,
)
't
will
be
very
difficult
to
be
sure
that
the
Baroscope
newly
made
in
a
remote
Country
,
is
as
Good
(
and
but
as
good
)
as
that
which
a
man
makes
use
of
in
this
;
in
regard
that
at
the
making
of
the
former
,
they
are
supposed
to
have
no
other
Baroscope
to
compare
it
with
;
and
to
be
sure
,
they
have
not
the
same
with
which
it
is
to
be
compared
Here.
Being
by
these
considerations
invited
to
attempt
the
making
of
Portable
or
Travailing
Baroscopes
,
(
if
I
may
so
call
them
,
)
I
thought
it
requisite
to
endeavour
these
three
things
:
The
first
,
to
make
the
vessel
that
should
contain
both
the
sustained
and
the
stagnant
Mercury
all
of
one
piece
of
Glass
,
of
a
like
bigness
:
The
next
,
to
place
this
vessel
,
when
fill'd
,
in
such
a
Frame
,
as
may
be
easie
to
be
transported
,
and
yet
in
a
reasonable
measure
defend
the
Glass
from
external
violence
,
no
part
of
it
standing
quite
out
of
the
Frame
,
as
in
all
other
Baroscopes
:
And
the
third
,
so
to
order
the
vessel
,
that
it
may
not
be
subject
to
be
easily
broken
by
the
violent
motion
of
the
Mercury
contain'd
in
it
.
The
first
of
these
will
not
seem
practicable
to
those
that
imagine
(
without
any
warrant
from
the
Hydrostaticks
)
that
t
is
as
well
necessary
as
usual
,
that
the
stagnant
Mercury
should
have
a
vessel
much
wider
than
the
Tube
,
wherein
the
Mercurial
Cylinder
is
sustain'd
;
but
to
us
the
difficulty
seem'd
much
less
to
make
the
Glass
part
of
our
Tube
of
one
piece
,
and
of
a
convenient
shape
,
than
afterwards
to
fill
it
.
But
to
do
both
,
we
took
a
Glass
Cylinder
seal'd
at
one
end
,
and
of
a
convenient
length
,
(
as
about
4
or
5
foot
,
)
and
caus'd
it
by
the
flame
of
a
Lamp
to
be
so
bent
,
that
,
to
those
that
did
not
take
notice
't
was
sealed
at
one
end
,
it
seem'd
to
be
a
Syphon
of
very
unequal
Legs
,
the
one
being
3
or
4
times
longer
than
the
other
;
by
virtue
of
which
Figure
the
shorter
Leg
may
serve
in
stead
of
the
distinct
vessel
usually
imployed
to
contain
the
stagnant
Mercury
.
To
fill
this
,
which
is
not
easie
,
one
may
proceed
after
this
manner
.
Take
a
small
Funnel
of
Glass
,
with
a
long
and
slender
Shank
,
so
that
it
may
reach
3
or
4
Inches
,
or
further
,
into
the
shorter
Leg
of
our
Barometrical
Syphon
(
if
I
may
so
call
it
;
)
and
by
this
Funnel
pour
into
this
shorter
Leg
as
much
Mercury
as
may
reach
about
2
or
3
Inches
in
both
Legs
;
then
stopping
the
Orifice
with
your
finger
,
and
slowly
inclining
the
Tube
,
the
Mercury
in
the
longer
Leg
will
gently
fall
to
the
sealed
end
;
and
the
Air
that
was
there
before
,
will
pass
by
it
,
and
so
make
it
room
.
The
Mercury
in
the
shorter
Leg
(
which
Leg
ought
to
be
held
uppermost
)
will
by
the
same
inclination
of
the
Tube
fall
towards
the
Orifice
,
but
,
being
by
the
finger
that
stops
that
,
kept
from
falling
out
,
if
you
do
slowly
reerect
the
Glass
,
and
then
make
it
stoop
again
as
much
as
before
,
the
Mercury
will
pass
out
of
the
shorter
Leg
into
the
longer
,
and
joyn
with
that
which
was
there
before
;
and
if
all
the
Mercury
do
not
so
pass
,
the
Orifice
is
to
be
stopt
again
with
your
Finger
,
and
the
Tube
inclin'd
as
formerly
.
This
done
,
the
Tube
is
to
be
erected
,
and
by
the
help
of
the
Funnel
more
Mercury
is
to
be
poured
in
,
and
the
foregoing
process
of
stopping
the
Orifice
,
inclining
the
Tube
&c.
is
to
be
repeated
,
till
all
the
Mercury
pour'd
into
the
shorter
Leg
,
be
brought
to
joyn
with
that
in
the
longer
;
and
then
the
open
Leg
is
to
be
furnisht
with
fresh
Mercury
,
observing
this
,
that
the
nearer
the
longer
Leg
comes
to
the
being
fill'd
,
the
less
you
must
raise
it
from
time
to
time
,
when
you
pour
Mercury
into
the
shorter
;
as
also
,
that
when
you
see
the
longer
Leg
quite
full
of
Mercury
,
(
though
there
be
but
litle
in
the
shorter
,
)
you
need
not
pour
in
any
more
,
if
the
longer
do
much
exceed
a
Yard
;
because
upon
the
restoring
of
the
Tube
to
an
erected
posture
there
will
subside
from
the
taller
leg
into
the
other
a
pretty
quantity
of
Mercury
,
by
reason
of
the
space
at
the
seal'd
end
,
which
will
be
deserted
by
the
Mercury
that
was
there
.
But
because
t
is
difficult
by
this
way
,
as
well
as
by
that
practised
already
,
to
fill
a
Tube
with
Mercury
without
leaving
any
visible
bubbles
;
to
free
it
from
such
(
if
any
happen
to
be
)
you
must
once
more
stop
the
Orifice
with
your
finger
,
and
incline
,
and
reerect
the
Tube
divers
times
,
till
you
have
thereby
brought
most
of
the
smaller
bubbles
into
one
greater
;
(
which
you
may
if
you
please
increase
,
by
letting
in
a
little
Air
:
)
for
by
making
this
Great
bubblle
pass
leisurely
two
or
three
times
from
one
end
of
the
Tube
to
the
other
,
it
will
in
its
passage
as
it
were
lick
up
all
the
small
Bubbles
,
and
unite
them
to
its
self
;
which
may
afterwards
by
one
inclination
more
of
the
Tube
be
made
to
pass
into
the
shorter
Leg
,
and
thence
into
the
free
Air.
But
there
is
another
sort
of
Funnels
,
which
if
one
have
the
skill
and
conveniency
to
make
,
(
as
I.
M.
easily
doth
,
)
one
may
very
expeditiously
fill
the
bended
Tubes
of
our
portable
Barometers
.
For
if
you
make
the
slender
part
of
the
Funnel
not
streight
but
bended
,
in
the
form
of
an
Obtuse
Angle
,
and
of
such
a
length
,
that
the
part
which
is
to
go
into
the
shorter
Leg
of
our
Siphon
may
reach
to
the
Flexure
(
of
the
Siphon
;
)
then
you
may
,
by
so
holding
the
Tube
that
the
sealed
end
be
somewhat
lower
than
the
other
,
and
by
pouring
in
Mercury
at
the
Obtuse
end
of
the
Angular
Funnel
,
easily
make
it
run
over
the
Flexure
into
the
longer
Leg
of
the
Siphon
;
provided
you
do
now
and
then
,
as
occasion
requires
,
erect
a
litle
and
shake
the
Tube
,
to
help
the
Mercury
to
get
by
the
Air
,
and
expell
it
.
By
such
wayes
as
these
we
have
found
by
Experience
,
that
t
is
possible
(
though
not
easie
)
to
do
in
such
a
bended
Glass
,
as
our
purpose
requires
,
what
,
besides
a
very
late
Learned
Writer
,
the
Diligent
Mersennus
himself
,
admonishes
his
Reader
,
that
t
is
not
a
practicable
thing
to
do
in
the
Ordinary
Glasses
of
the
Torricellian
Experiment
,
viz.
to
free
the
Mercury
of
a
straight
Tube
from
Air
and
Bubbles
,
(
s
as
to
be
able
by
inclining
the
Glass
to
make
the
Liquor
ascend
to
the
very
top
.
)
The
First
of
our
3
above
mentioned
Scopes
being
thus
attained
,
it
was
not
difficult
to
compass
the
Second
,
by
the
help
of
a
solid
piece
of
Wood
,
which
is
to
be
somewhat
longer
than
the
Tube
,
and
a
good
deal
broader
in
the
lower
part
than
in
the
upper
,
that
it
may
receive
the
shorter
Leg
of
the
Siphon
.
In
such
a
piece
of
Wood
,
which
was
about
an
Inch
thick
,
we
caus'd
to
be
made
a
Gutter
or
Channel
,
of
such
a
depth
and
shape
,
that
our
Siphon
might
be
placed
in
it
so
deep
,
that
a
flat
piece
of
Wood
(
like
a
plain'd
Lath
)
might
be
layd
upon
it
,
without
at
all
pressing
upon
or
so
much
as
touching
the
Glass
;
so
that
this
piece
of
Wood
may
serve
for
a
Cover
to
defend
the
Glass
,
to
be
put
on
when
the
Instrument
is
to
be
transported
,
and
taken
off
again
when
t
is
to
be
hung
up
to
make
Observations
with
;
the
Channel-piece
of
wood
serving
both
for
a
part
of
a
Case
,
and
for
an
entire
Frame
;
which
may
for
some
uses
be
a
litle
more
commodious
,
if
the
Cover
be
joyned
(
as
it
may
easily
be
)
to
the
rest
of
the
Frame
,
by
2
or
3
litle
Hinges
and
a
Hasp
,
by
whose
help
the
Case
may
be
readily
opened
and
shut
at
pleasure
.
The
3d
d
thing
we
proposed
to
our selves
is
nothing
near
so
easie
as
the
2d
,
nor
have
we
yet
had
opportunity
to
try
,
whether
the
way
we
made
use
of
will
hold
,
if
the
Barometer
be
transported
into
very
remote
parts
,
though
by
smaller
Removes
we
found
cause
to
hope
that
't
will
succeed
in
Greater
.
The
Grand
difficulty
to
be
obviated
was
this
;
That
though
't
were
easie
to
hinder
the
spilling
of
the
Mercury
,
by
stopping
the
Orifice
of
the
shorter
Leg
of
our
Siphon
,
yet
that
would
not
serve
the
turn
;
for
the
upper
part
of
the
Tube
being
destitute
of
Air
,
if
the
Mercury
be
by
the
motion
of
the
Instrument
put
to
vibrate
,
it
will
be
apt
(
for
want
of
meeting
with
any
Air
in
the
upper
part
of
the
Tube
to
check
its
motions
)
to
hit
so
violently
against
the
Top
of
the
Glass
as
to
beat
it
out
,
or
to
crack
some
of
the
neighbouring
parts
.
To
obviate
this
great
inconvenience
our
way
is
,
to
incline
the
Tube
,
till
the
Mercury
be
impell'd
to
the
very
top
of
it
,
and
yet
there
will
remain
a
competent
quantity
in
the
shorter
leg
of
the
Glass
,
if
that
be
not
at
first
made
too
short
.
This
done
,
the
remaining
part
of
the
shorter
Leg
is
to
be
quite
fill'd
up
either
with
Water
or
Mercury
,
and
the
Orifice
of
it
is
to
be
very
carefully
and
firmly
stopt
,
(
for
which
purpose
we
use
our
strong
black
Cement
:
)
for
by
this
means
the
Mercury
in
the
longer
Leg
,
having
no
room
to
play
,
cannot
strike
with
violence
as
before
,
against
the
top
of
the
Glass
.
But
though
by
many
times
successively
shaking
the
Baroscope
we
did
not
perceive
that
't
was
very
like
to
be
prejudiced
by
the
shakes
it
must
necessarily
indure
in
Transportation
to
remote
places
,
if
due
care
be
had
of
it
by
the
way
,
yet
till
further
Tryal
have
been
made
I
shall
not
pretend
to
be
certain
of
the
Event
.
But
thus
much
of
conveniency
we
have
already
found
in
this
Contrivance
,
that
we
sent
it
some
miles
off
to
the
top
of
a
Hill
,
and
had
it
brought
home
safe
again
,
the
phaenomena
at
the
top
and
bottom
of
the
Hill
being
answerable
to
what
we
might
have
expected
if
we
had
imployed
another
Baroscope
.
When
the
Instrument
is
to
be
sent
away
,
the
height
of
the
Mercurial
Cylinder
(
to
be
measured
from
the
surface
of
the
stagnant
Mercury
in
the
shorter
Leg
)
being
taken
for
that
place
,
day
,
and
hour
,
and
compar'd
(
if
it
may
be
)
with
that
of
another
good
Baroscope
,
which
is
to
continue
in
that
place
;
as
much
of
the
Gutter
as
is
unfill'd
by
the
Glass
may
be
well
stuffed
with
Cotten
,
or
some
such
thing
,
to
keep
the
Glass
the
more
firm
in
its
posture
;
and
that
the
Tube
be
not
shaken
or
press'd
against
the
Wood
,
some
of
the
same
matter
may
be
put
between
the
rest
of
the
Frame
and
the
Cover
,
which
ought
to
be
well
bound
together
.
And
when
the
Instrument
is
arriv'd
at
the
remote
place
where
t
is
to
be
imployed
,
(
for
if
it
be
to
be
sent
but
a
litle
way
,
it
may
be
carried
safely
without
using
any
adventitious
Liquor
,
)
the
Water
that
is
added
,
may
be
taken
off
again
,
by
soaking
it
up
with
pieces
of
Sponge
,
Linnen
,
&c.
but
if
in
stead
of
Water
you
put
in
Mercury
,
as
it
ought
to
have
been
put
in
by
Weight
,
so
it
is
to
be
taken
out
,
till
you
have
just
the
Weight
that
was
put
in
:
and
t
is
not
difficult
to
take
out
the
Mercury
by
degrees
,
by
the
help
of
a
small
Glass-pipe
,
since
You
may
either
suck
up
litle
by
little
as
much
as
remains
of
the
additional
Mercury
,
when
by
erecting
the
Barometer
,
and
warily
unstopping
the
Orifice
of
the
lower
Leg
,
as
much
Mercury
as
will
of
its
self
flow
out
is
efflux'd
;
or
else
you
may
take
out
the
superfluous
Mercury
,
by
thrusting
the
lower
end
of
the
litle
Pipe
into
that
Liquor
,
and
when
it
has
taken
in
enough
,
stopping
the
upper
end
close
with
your
finger
,
to
keep
it
from
falling
back
again
when
you
remove
the
Pipe
.
NB.
If
it
should
happen
in
a
long
voyage
,
that
by
the
numerous
Shakings
of
the
Instrument
there
should
from
the
additional
Water
or
Mercury
in
the
shorter
Leg
get
up
into
the
longer
any
litle
Aerial
Bubble
,
which
seems
the
onely
(
but
I
hope
not
likely
)
danger
in
this
Contrivance
,
he
that
is
to
use
the
Instrument
,
at
the
end
of
the
Voyage
may
,
if
he
be
skilful
,
free
the
Mercury
from
it
by
the
same
way
,
that
we
lately
prescrib'd
to
free
it
from
Air
,
when
the
Instrument
was
first
fill'd
.
I
presume
I
need
not
tell
Your
Lordship
,
that
the
chief
use
of
this
Travailing
Baroscope
is
,
That
he
that
uses
it
in
a
remote
part
,
keeping
a
Diary
of
the
heights
of
the
Mercury
,
by
comparing
these
heights
with
those
at
which
the
Mercury
stood
at
the
same
times
in
the
Barometer
that
was
not
remov'd
,
the
Agreement
or
Difference
of
the
weight
of
the
Atmosphere
in
distant
places
may
be
observed
.
To
which
this
may
be
added
,
the
Conveniency
,
which
the
structure
of
these
Instruments
gives
them
to
be
securely
let
down
into
deep
Wels
or
Mines
,
and
to
be
drawn
up
to
the
top
of
Towers
and
Steeples
,
and
other
elevated
places
:
not
here
to
consider
,
whether
by
a
convenient
addition
,
these
,
as
well
as
some
other
Barometers
,
may
not
be
made
to
discover
even
very
minute
Alterations
of
the
Atmospheres
Pressure
.
Whether
this
Travailing
Baroscope
,
being
furnish'd
at
its
upper
end
with
a
very
good
Ball
and
Socket
,
and
at
the
lower
end
with
a
great
weight
,
(
which
way
of
keeping
things
steady
in
a
Ship
has
been
happily
used
by
the
Royal
Society
on
another
occasion
,
)
whether
,
I
say
,
our
Instrument
may
by
this
Contrivance
,
or
some
other
that
might
be
suggested
to
the
same
purpose
,
be
made
any
thing
serviceable
at
Sea
,
notwithstanding
the
differing
motions
of
the
Ship
,
I
have
had
no
opportunity
to
try
:
but
whether
it
may
or
may
not
be
useful
in
spite
of
the
rolling
of
the
Ship
,
it
may
at
least
be
made
use
of
in
flat
Calms
,
(
which
divers
times
happen
in
long
Voyages
,
especially
to
the
East-Indies
,
and
to
Africk
,
)
and
then
the
Instrument
,
which
at
other
times
may
lie
by
without
being
at
all
cumbersom
,
may
be
made
use
of
,
as
long
as
the
Calm
lasts
,
to
acquaint
the
Observer
with
the
weight
of
the
Atmosphere
in
the
Climate
where
he
is
,
and
that
upon
the
Sea
:
which
may
give
some
welcome
Information
to
the
Curiosity
of
Speculative
Naturalists
,
and
perhaps
prove
either
more
directly
or
in
its
consequences
of
some
use
to
Navigators
themselves
,
as
by
enabling
them
by
its
suddain
changes
to
foretell
the
end
of
the
Calme
.
Besides
that
,
having
one
of
these
Instruments
ready
at
hand
,
where
ever
they
set
foot
on
shore
,
though
it
be
but
upon
a
small
Island
,
or
a
Rock
,
they
can
presently
and
easily
take
notice
of
the
Gravity
of
the
Atmosphere
in
that
place
;
which
whether
or
no
,
if
compared
with
other
Observations
,
it
may
in
time
prove
not
altogether
useless
to
the
Guessing
whereabouts
they
are
,
and
the
foreseeing
some
aproaching
changes
of
Weather
,
I
leave
to
future
Experience
,
if
it
shall
be
thought
worth
the
making
,
to
determine
.
Besides
the
ordinary
Baroscope
,
and
this
Travailing
one
,
I
have
imployed
2
or
3
other
Instruments
of
quite
differing
kinds
,
to
discover
the
varying
Gravities
of
the
Atmosphere
;
but
though
they
have
hitherto
succeeded
well
(
for
the
main
,
)
yet
being
willing
to
make
further
Observations
about
them
,
I
reserve
one
of
them
for
another
opportunity
,
and
think
fit
to
leave
the
other
in
a
Tract
it
belongs
to
.
A
Post-script
Advertisment
.
SInce
the
writing
of
the
foregoing
and
the
following
Experiments
about
the
Travailing
Baroscope
,
having
had
occasion
to
make
one
at
a
place
about
50
miles
distant
from
that
where
I
was
when
I
writ
them
,
I
took
notice
,
that
the
Mercury
in
the
Travailing
Baroscope
was
not
by
1/4
of
an
Inch
so
high
as
that
in
another
Baroscope
made
the
ordinary
way
;
and
yet
't
was
not
easie
to
perceive
,
that
the
former
had
been
less
carefully
fill'd
than
the
latter
.
So
that
I
yet
know
not
well
to
what
cause
to
impute
the
Difference
,
unless
it
should
perhaps
depend
upon
this
Circumstance
;
That
the
Pipe
,
whereof
the
Travailing
Baroscope
was
made
,
was
very
slender
,
and
much
more
so
than
the
Tube
of
the
other
;
and
I
have
already
elsewhere
observed
,
that
Mercury
,
contrary
to
what
happens
in
Water
,
is
lesse
apt
to
rise
in
very
slender
Pipes
.
And
though
I
remember
that
,
at
the
Place
where
I
writ
the
Experiment
,
to
which
this
Postscript
belongs
,
in
the
Tube
I
then
imployed
to
make
the
Travailing
Baroscope
,
the
Mercury
ascended
as
high
as
in
a
noted
one
made
the
common
way
,
yet
not
being
in
the
other
place
furnished
with
a
Tube
long
and
big
enough
,
I
think
my self
oblig'd
,
till
I
can
clear
the
Doubt
by
further
Tryal
,
to
give
Your
Lordship
this
Advertisement
,
lest
either
the
Cause
already
suspected
,
or
some
other
unheeded
thing
may
in
some
cases
make
these
Travailing
Baroscopes
somewhat
differing
from
others
.
But
though
they
should
prove
to
be
so
,
yet
it
would
not
follow
that
they
cannot
be
made
serviceable
:
for
keeping
a
pretty
while
that
Instrument
,
which
suggested
the
Scruple
to
me
,
just
by
the
other
with
which
I
had
compar'd
it
,
and
carefully
taking
notice
of
the
respective
heights
at
which
the
Mercury
rested
in
both
,
I
observ'd
that
when
it
rose
or
fell
in
the
other
Barometer
,
it
did
also
rise
and
fall
in
the
Portable
one
;
and
when
it
rested
at
its
first
station
in
the
Fromer
,
it
did
so
in
the
Later
;
and
though
there
seem'd
to
be
an
inequality
in
the
quantity
of
the
Ascent
,
and
subsidence
of
the
Mercury
in
the
two
Instruments
,
yet
that
seem'd
to
be
accountable
for
by
some
Circumstances
,
especially
the
very
unequal
breadth
of
the
vessel
that
contain'd
the
stagnant
Mercury
in
the
other
Barometer
,
and
that
shorter
Leg
which
answer'd
to
that
vessel
in
the
Travailing
Barometer
.
But
till
the
formerly
proposed
Scruple
be
by
further
Observation
removed
,
the
safest
way
will
be
to
make
the
Barometer
to
be
sent
to
remote
places
,
as
like
as
may
be
(
in
highness
,
and
length
of
the
Tube
)
to
another
Portable
one
kept
at
home
;
that
so
when
they
are
once
adjusted
,
the
Collations
may
be
made
betwixt
two
Instruments
of
the
same
kind
,
whereof
that
which
is
kept
at
home
may
also
,
if
it
be
thought
fit
,
be
compared
,
when
the
Observations
are
made
,
with
a
Baroscope
made
the
ordinary
way
.
EXPERIMENT
XXIII
.
Confirming
,
that
Mercury
in
a
Barometer
will
be
kept
suspended
higher
at
the
top
,
than
at
the
bottom
of
a
Hill
.
On
which
occasion
something
is
noted
about
the
height
of
Mountains
,
especially
the
Pic
of
Tenariff
.
TO
give
Your
Lordship
some
Instance
(
till
I
can
present
You
with
a
Nobler
one
)
of
the
Use
of
our
Travailing
Barometer
,
I
shall
now
adde
:
That
when
I
writ
the
foregoing
Experiment
,
chancing
to
be
within
2
or
3
miles
of
a
Hill
,
which
,
though
not
high
,
was
the
least
low
in
that
Countrey
,
I
thought
our
Instrument
might
be
sfely
,
and
not
altogether
uselesly
,
carried
on
Horse-back
to
the
top
of
it
,
which
was
too
remote
from
the
bottom
to
be
conveniently
reacht
by
me
on
foot
in
the
midst
of
Winter
.
This
Tryal
therefore
I
resolv'd
to
make
,
because
,
though
I
formerly
told
you
of
a
considerable
one
that
had
been
made
in
France
by
some
Eminent
Virtuosi
of
the
Country
,
yet
I
was
willing
,
not
onely
to
have
a
Proof
how
safely
our
Baroscope
might
be
transported
,
but
to
confirm
to
Your
Lordship
upon
our
own
Observation
,
made
in
another
Region
,
so
considerable
an
Argument
,
as
these
kind
of
Experiments
afford
to
our
Hypothesis
:
And
though
when
I
came
to
try
the
Experiment
,
I
hapned
to
have
an
Indisposition
that
forbid
me
to
do
it
all
my Self
,
yet
having
carefully
mark'd
on
the
edge
of
the
Frame
the
height
to
which
the
suspended
Quick-silver
reach'd
,
and
compar'd
it
with
a
good
Baroscope
made
the
ordinary
way
,
I
commmitted
our
Instrument
to
a
couple
of
Servants
,
that
I
had
often
imployed
about
Pneumatical
and
Mercurial
Experiments
,
giving
them
particular
Instructions
what
to
do
.
And
the
Instrument
being
such
as
might
be
safely
carried
on
Horseback
,
I
had
in
two
or
three
hours
an
Account
brought
me
back
,
the
Summe
of
which
was
:
That
they
found
the
suspended
Mercury
fall
a
litle
as
they
ascended
the
Hill
,
at
whose
Top
they
gave
the
Liquor
leave
to
setle
,
and
carefully
took
notice
by
a
mark
of
the
Place
it
rested
at
;
which
was
;
as
I
afterwards
found
,
¼
of
an
Inch
,
or
somewhat
better
beneath
the
Mark
I
had
made
,
and
this
notwithstanding
the
Hill
was
not
high
,
and
the
Air
and
Wind
seem'd
to
them
to
be
much
colder
at
the
top
of
it
,
than
beneath
.
But
though
,
as
they
descended
more
and
more
,
they
observ'd
the
Mercury
to
rise
again
higher
and
higher
,
(
as
being
press'd
against
by
a
taller
column
of
the
Atmosphere
,
)
and
though
consequently
the
Experiment
agreed
very
well
with
our
Hypothesis
,
and
may
serve
for
a
Confirmation
of
it
;
yet
by
reason
of
the
small
height
of
the
Mountain
the
Decrement
of
the
height
of
the
Mercurial
Cylinder
was
not
so
considerable
,
but
that
I
should
perhaps
have
omitted
the
mention
of
this
Tryal
,
if
it
did
not
shew
that
our
Travailing
Baroscopes
may
be
fit
to
be
imployed
about
such
Experiments
.
And
therefore
,
when
I
can
recover
some
of
my
scatter'd
Papers
,
I
shall
by
way
of
Appendix
subjoin
to
this
some
other
Observations
,
that
I
procur'd
to
be
made
by
Ingenious
men
,
who
had
the
Opportunity
of
living
near
higher
Mountains
.
Some
further
Tryals
I
have
recommended
to
be
hereafter
made
by
some
other
inquisitive
Persons
;
and
to
make
them
the
more
instructive
,
I
could
wish
that
others
would
do
what
I
should
have
done
,
if
Opportunity
had
befriended
me
.
For
I
design'd
to
make
the
Experiment
at
the
bottom
,
the
top
,
and
the
intermediate
part
of
the
hill
,
at
three
differing
constitutions
of
Air
;
viz.
when
it
should
appear
by
a
good
ordinary
Baroscope
,
that
the
Atmosphere
was
very
heavy
,
when
it
should
be
found
to
be
very
light
,
and
when
it
should
have
a
moderate
degree
of
Gravity
:
And
I
hoped
,
that
if
sagacious
Experimenters
should
make
these
diversity'd
Observations
on
distant
and
unequal
Hils
,
good
Hints
may
result
from
the
Collations
that
may
be
made
of
the
varying
Decrements
of
the
Mercurial
Cylinders
height
,
according
to
the
differing
Gravities
of
the
Atmosphere
at
several
Times
,
and
the
differing
heights
of
the
Hils
and
Stations
where
the
Observations
should
be
made
.
I
also
indeavoured
to
get
a
Baroscope
carried
down
to
the
bottoms
of
deep
Mines
;
partly
,
to
try
whether
the
Atmospherical
Pillar
being
longer
There
then
at
the
Top
,
the
Mercury
in
the
Tube
would
not
be
impell'd
up
higher
;
and
partly
,
in
order
to
other
Discoveries
.
But
some
Impediments
in
the
structure
of
those
Mines
made
it
not
very
Practicable
to
imploy
Barometers
there
;
which
yet
makes
me
not
despair
of
Success
in
some
other
Mines
,
where
the
Shafts
or
Pits
are
sunck
more
perpendicularly
.
Perhaps
I
told
Your
Lordship
already
by
word
of
mouth
,
that
I
have
been
sollicitously
endeavouring
to
get
the
Torricellian
Experiment
tried
upon
the
Pic
of
Teneriff
,
but
hitherto
I
have
had
no
Account
of
the
success
of
my
Endeavours
;
for
which
I
am
the
more
concern'd
,
because
of
the
Eminent
(
if
not
Matchless
)
height
of
the
Mountain
,
of
which
You
may
receive
some
Satisfaction
,
by
what
I
am
going
to
subjoin
about
it
.
An
Appendix
about
the
height
of
Mountains
.
FOrasmuch
as
on
the
one
hand
not
onely
Kepler
,
but
divers
other
modern
Writers
of
Note
,
do
endeavour
to
straiten
the
Atmosphere
,
and
make
it
lower
by
half
than
the
least
height
to
which
,
according
to
our
Estimation
,
it
should
reach
;
and
to
countenance
their
Opinion
,
will
not
allow
the
Clouds
to
be
often
above
a
Mile
high
,
(
nor
even
the
highest
Mountains
to
exceed
two
miles
.
)
And
forasmuch
as
on
the
other
side
other
Learned
men
seem
to
make
the
Clouds
and
the
Mountains
of
a
stupendous
height
;
we
,
who
take
a
middle
way
of
estimating
the
height
of
the
one
and
the
other
,
hold
it
not
unfit
to
subjoyn
on
this
occasion
some
uncommon
Observations
,
in
favour
of
our
Opinion
,
that
we
have
obtain'd
from
inquisitive
Travellers
.
But
first
I
will
subjoyn
a
Passage
I
have
somewhere
met
with
in
Ricciolus
his
Almigestum
novum
,
where
he
(
if
I
well
remember
)
relates
,
that
the
Rector
Metensis
(
as
he
calls
him
)
of
the
Jesuites
Colledg
affirm'd
to
him
some
years
since
,
that
he
had
measured
the
height
of
many
Clouds
,
without
having
found
any
of
them
higher
than
5000
paces
:
which
argues
,
that
he
met
with
some
so
high
,
though
indeed
the
height
of
Clouds
must
needs
bevery
various
,
according
to
the
Gravity
or
Lightness
,
Density
or
Thinness
,
Rest
or
Agitation
of
the
Air
,
and
the
condition
of
the
Vapors
&
Exhaltations
they
consist
of
.
And
if
either
that
be
true
which
we
have
formerly
had
occasion
to
mention
concerning
Maignan's
Observation
,
or
if
it
be
true
that
Sublunary
Comets
(
for
I
speak
not
of
Celestial
ones
)
are
Generated
of
Exhalations
of
the
Terrestrial
Globe
,
we
may
well
conjecture
that
the
Atmosphere
,
(
especially
if
its
height
be
not
uniform
,
)
and
even
Clouds
(
especially
those
that
have
most
Fumes
,
and
fewest
Vapors
)
may
reach
much
higher
than
Cardan
,
Kepler
,
and
others
have
defin'd
.
But
of
the
height
of
Clouds
(
which
we
have
sometimes
attempted
to
take
Geometrically
)
we
may
have
elsewhere
occasion
to
speak
again
;
and
therefore
I
shall
now
proceed
to
what
I
have
to
say
concerning
the
Height
of
Mountains
.
Which
being
an
Enquiry
curious
and
difficult
enough
in
it self
,
and
of
some
Importance
in
the
Disquisition
about
the
height
of
the
Atmosphere
,
(
it
being
evident
that
That
must
reach
at
least
as
high
as
the
tops
of
Mountains
,
upon
whose
tops
men
can
live
;
)
I
hope
it
will
not
be
unacceptable
to
Your
Lordship
,
if
having
a
while
since
(
as
I
was
intimating
)
had
the
opportunity
to
discourse
with
some
credible
Persons
that
have
been
upon
the
top
of
exceeding
high
mountains
,
particularly
of
the
Pic
of
Tenariff
,
(
and
especially
with
one
Gentleman
,
who
was
a
few
dayes
before
brought
to
satisfie
the
Curiosity
of
our
Inquisitive
and
Discerning
Monarch
,
by
giving
him
an
Account
of
his
Journey
,
)
I
acquaint
You
with
those
of
the
Particulars
,
which
I
learn'd
from
thence
,
that
are
the
most
pertinent
to
our
present
purpose
.
First
then
whereas
divers
late
Mathematicians
will
not
allow
above
two
miles
or
half
a
German
league
(
and
some
of
them
not
half
so
much
)
to
the
height
of
the
highest
Mountain
;
the
Mountain
we
speak
of
,
in
the
Island
of
Tenariff
,
one
of
the
Canaries
or
Fortunate
Islands
,
so
high
,
that
,
though
perhaps
I
think
those
Travellers
I
have
taken
notice
of
,
speak
with
the
most
when
they
write
,
that
the
top
of
this
Mountain
is
to
be
seen
at
Sea
4
degrees
off
,
i.
e.
at
least
threescore
German
Leagues
;
yet
having
ask'd
the
ingenious
Gentleman
lately
mentioned
,
Mr.
Sydenham
,
from
what
distance
the
top
of
the
Sugar-loaf
(
or
highest
part
of
the
Hill
,
so
called
from
its
Figure
)
could
be
seen
at
Sea
,
according
to
the
common
opinion
of
Seamen
?
he
answer'd
,
that
that
Distance
was
wont
to
be
reckon'd
60
Sea-leagues
,
of
3
miles
to
a
League
:
adding
,
that
he
himself
had
seen
it
about
40
leagues
off
,
and
yet
it
appear'd
exceeding
high
,
and
like
a
blewish
Pyramid
,
manifestly
a
great
deal
higher
than
the
Clouds
.
And
what
he
related
to
me
about
the
Distance
,
was
afterwards
confirmed
by
the
Answers
I
receiv'd
from
observing
men
of
differing
Nations
,
who
had
sail'd
that
way
;
and
particularly
by
a
Noble
Virtuoso
,
skill'd
in
the
Mathematicks
,
who
was
then
Admiral
of
a
brave
English
Fleet
:
And
the
above
mentioned
Gentleman
(
M
r
S.
)
also
told
me
,
that
sometimes
men
could
from
thence
see
the
Island
of
Madera
,
though
distant
from
it
70
leagues
;
and
that
the
Great
Canary
,
though
18
leagues
off
,
seem'd
to
be
very
near
them
that
were
on
the
top
of
the
Sugar-loaf
,
as
if
they
might
leap
down
upon
it
:
Thus
far
Mr
Sydenham
.
By
whose
Relation
it
appears
,
that
this
Pic
must
be
far
higher
than
Kepler
and
others
allow
Mountains
to
be
:
for
else
it
could
not
be
seen
at
Sea
from
so
great
a
Distance
.
And
the
Learned
Ricciolus
supposing
it
to
be
(
as
some
Navigators
report
it
to
be
)
discoverable
at
Sea
4
degrees
off
,
calculates
its
height
measur'd
by
a
Perpendicular
line
,
and
allowing
too
for
Refraction
,
to
amount
to
Ten
miles
,
which
Altitude
also
the
accurate
Snellius
assigns
it
.
But
I
fear
this
Learned
man
may
have
been
somewhat
misinform'd
by
the
Navigators
he
relyes
on
,
or
else
that
the
way
of
allowing
for
Refractions
is
not
yet
reduc'd
to
a
sufficient
Certainty
.
For
I
do
not
find
by
those
who
have
purposely
gone
to
the
top
of
it
,
that
the
Mountain
is
so
high
as
his
Calculation
makes
it
.
And
whereas
the
same
Eminent
Writer
resolutely
ponounces
that
the
Height
of
mount
Caucasus
,
Deduction
being
made
for
Refraction
,
is
51
Bolonian
miles
,
(
which
are
considerably
greater
than
the
Roman
miles
,
)
I
doubt
that
here
likewise
,
though
I
question
not
his
Supputations
if
You
grant
him
the
Grounds
of
them
,
he
makes
this
Mountain
far
higher
than
indeed
it
is
.
For
the
Passage
of
Aristotle
,
on
which
he
founds
his
Opinion
,
is
obscure
enough
;
and
Aristotle
,
himself
does
sometimes
take
up
Reports
upon
Hear-say
,
without
over-strictly
examining
their
Truth
or
Probability
;
whereas
all
the
Navigators
and
Travellers
I
have
hitherto
met
with
,
(
and
Your
Lordship
knows
,
that
I
have
upon
a
Publick
Account
the
opportunity
of
meeting
often
with
such
men
,
)
do
almost
unanimously
agree
,
that
the
Pic
of
Teneriff
is
the
highest
Mountain
hitherto
known
in
the
World
,
and
yet
that
is
so
far
from
being
15
leagues
high
,
(
as
some
Eminent
and
even
late
Writers
would
perswade
us
,
)
that
it
is
scarce
a
7th
part
so
high
as
Ricciolus
computes
Mount
Caucasus
to
be
.
For
having
ask'd
Mr
Sydenham
,
and
others
,
what
was
the
Estimate
made
by
the
most
knowing
Persons
of
the
Island
of
the
height
of
the
Hill
,
he
told
me
that
his
Guides
accounted
it
to
be
one
and
twenty
mile
high
from
the
Town
called
L'oretava
,
seated
on
the
lower
part
of
the
Hill
;
from
which
.
town
to
the
Sea
there
is
3
miles
of
way
alwayes
descending
.
But
in
regard
that
the
way
,
which
amounted
to
21
miles
in
length
,
is
,
as
other
wayes
whereby
steep
places
are
wont
to
be
ascended
,
made
to
wind
and
turn
for
the
conveniency
of
Travellers
;
I
can
scarce
deduct
less
than
2
thirds
for
the
Crookedness
of
the
way
:
and
accordingly
having
ask'd
him
,
whether
the
Perpendicular
height
of
it
had
been
accurately
taken
by
any
with
Mathematical
Instruments
,
he
answered
,
that
he
could
say
nothing
to
that
upon
his
own
knowledg
,
but
that
a
Sea-man
with
great
confidence
affirmed
himself
to
have
accurately
enough
measur'd
it
by
Observations
made
in
a
Ship
,
and
to
have
found
the
Perpendicular
height
of
the
Hill
to
be
about
7
miles
.
Which
Estimate
agrees
well
enough
with
the
Calculations
of
Ricciolus
and
Snellius
,
if
we
lessen
the
Distance
from
which
the
top
of
the
Hill
is
to
be
discovered
,
from
60
German
leagues
of
4
miles
to
a
League
,
to
the
like
number
of
common
Leagues
at
3
miles
to
a
League
.
And
because
eminent
Writers
have
so
confidently
deliver'd
prodigious
things
touching
the
height
of
this
Mountain
,
I
will
here
,
to
confirm
the
Estimate
already
made
,
adde
these
Particulars
,
which
I
took
from
the
Gentleman
's
own
mouth
,
(
and
which
were
afterwards
confirm'd
to
me
by
another
that
went
with
him
,
and
partly
also
by
a
3d
d
,
who
went
up
to
the
top
at
another
time
of
the
Year
,
)
viz.
That
they
begun
their
Journey
from
L'oretava
on
the
18th
of
August
,
about
10
of
the
Clock
at
night
,
and
travell'd
till
Five
in
the
Afternoon
on
the
Munday
following
,
resting
two
Hours
by
the
way
,
and
travelling
about
10
miles
of
their
way
upon
Mules
,
which
afterwards
they
were
forc'd
to
leave
,
and
betake
themselves
to
their
feet
.
Resting
upon
Munday
till
midnight
,
they
resum'd
their
journeying
,
and
travell'd
till
about
Nine
the
next
morning
,
at
which
time
they
arriv'd
at
the
top
of
the
Sugar-loaf
,
or
highest
Pile
of
the
Mountain
;
so
that
they
travell'd
in
all
but
26
hours
,
in
which
,
considering
the
steepness
and
ruggedness
of
the
ways
,
and
that
they
were
forc't
to
goe
above
half
way
on
foot
,
to
which
they
were
unaccustomed
,
t
is
likely
enough
that
the
length
of
the
way
did
not
much
,
if
at
all
,
exceed
the
Computation
of
the
Guides
.
We
have
since
endeavour'd
,
but
without
yet
knowing
what
will
be
the
succes
,
to
have
the
height
of
this
Mountain
carefully
taken
by
skilful
men
.
In
the
interim
I
shall
not
deny
,
but
that
if
what
Aristotle
and
other
Authors
report
of
Mount
Caucasus
be
true
,
there
may
be
far
higher
Mountains
than
the
Pic
of
Tenariff
;
especially
since
there
is
one
Consideration
,
which
perhaps
You
will
not
think
despicable
,
that
I
find
not
taken
notice
of
by
those
that
have
written
of
the
height
of
Mountains
;
viz.
That
of
two
Mountains
that
,
But
to
return
to
the
height
of
the
Atmosphere
;
in
order
to
the
making
an
Estimate
of
what
we
have
consider'd
as
to
the
height
of
Mountains
,
I
shall
adde
,
that
though
by
what
has
been
already
said
touching
the
height
of
the
Pic
,
and
other
Hills
,
it
appears
,
that
the
Atmosphere
reaches
far
higher
than
many
learned
men
would
hitherto
allow
,
yet
we
are
not
to
think
that
the
Atmosphere
may
not
reach
almost
incomparably
higher
than
the
tops
of
Mountains
.
Nor
do
I
suffer
my self
to
be
concluded
by
what
many
Comentators
of
Aristotle
and
other
Writers
are
wont
to
teach
touching
the
distinct
narrow
Extent
they
allow
to
that
Sphere
,
within
whose
Limits
they
would
have
the
Steams
of
the
Terrestrial
Globe
to
produce
Meteors
.
How
far
the
Height
of
Mountains
may
make
the
Air
at
the
tops
of
them
inconvenient
for
Respiration
,
shall
be
(
God
permitting
)
consider'd
,
when
I
come
to
acquaint
Your
Lordship
with
my
loose
Tryals
about
Respiration
.
EXPERIMENT
XXIV
.
Shewing
that
the
Pressure
of
the
Atmosphere
may
be
exercis'd
enough
to
keep
up
the
Mercury
in
the
Torricellian
Experiment
,
though
the
Air
press
upon
it
at
a
very
small
Orifice
.
BY
a
very
slight
variation
of
the
foregoing
22th
Experiment
we
may
both
confirm
one
of
the
most
important
and
the
least
likely
Truths
of
the
Hydrostaticks
,
and
remove
an
Objection
,
which
,
for
want
of
the
knowledg
of
this
Truth
,
is
wont
to
be
urg'd
against
your
Hypothesis
even
by
Learned
men
.
For
divers
of
these
,
when
they
see
the
same
Phaenomena
happen
in
the
Torricellian
Experiment
,
whether
it
be
made
in
the
open
Air
,
or
in
a
Chamber
,
are
forward
to
object
,
That
if
it
were
,
as
we
say
t
is
,
the
weight
of
the
Air
,
incumbent
on
the
stagnant
Mercury
,
which
keeps
that
suspended
in
the
Tube
from
falling
down
,
the
Mercury
would
not
be
sustain'd
at
any
thing
near
the
same
height
in
the
open
Air
,
where
the
Pillar
that
is
suppos'd
to
lean
upon
the
stagnant
Mercury
,
may
reach
up
to
the
top
of
the
Atmosphere
,
as
in
a
close
room
,
where
they
imagine
that
no
more
Air
can
press
upon
it
,
than
what
reaches
directly
up
to
the
Roof
or
Sealing
.
And
when
to
this
t
is
answer'd
,
that
though
if
a
Room
were
indeed
exactly
clos'd
,
the
Sustentation
of
the
Mercury
ought
to
be
ascrib'd
to
some
other
cause
than
the
weight
of
the
Imprison'd
Air
,
(
which
other
Cause
I
have
elsewhere
shewn
to
be
its
Spring
;
)
yet
in
ordinary
Rooms
there
is
still
a
Communication
between
the
internal
and
external
Air
,
either
by
the
Chimney
,
or
,
if
the
Room
have
none
,
by
some
Crevice
in
the
Window
,
or
by
some
Chink
between
the
Wall
and
the
Door
,
or
at
least
by
the
Key-hole
.
And
when
to
this
t
is
objected
,
that
the
Orifice
of
the
Keyhole
is
much
narrower
than
the
Superficies
of
the
stagnant
Mercury
,
and
consequently
,
though
the
Atmosphere
were
not
reduc'd
to
press
obliquely
on
the
Mercury
,
yet
,
entring
at
so
small
an
Orifice
,
it
could
not
press
sufficiently
upon
it
;
when
,
I
say
,
in
answer
to
this
Objection
I
have
alleadg'd
that
Hydrostatical
Theoreme
,
That
the
Pressure
,
in
such
cases
as
ours
,
is
to
be
estimated
by
the
heights
of
the
Liquors
and
not
the
breadths
,
the
Assertion
has
been
thought
unlikely
and
precarious
.
To
confirm
therefore
this
Hydrostatical
Truth
,
one
may
take
the
bended
Tube
,
mention'd
in
the
22th
Experiment
;
and
inclining
it
till
the
greatest
part
of
the
Mercury
pass
from
the
shorter
Leg
into
the
longer
,
the
upper
end
of
this
shorter
Leg
may
by
the
flame
of
a
Lamp
be
drawn
out
so
slender
,
that
the
Orifice
of
it
shall
not
be
above
an
8th
or
10th
part
(
not
to
say
a
much
lesse
)
as
big
as
't
was
before
.
For
this
being
done
,
and
the
Tube
erected
again
,
if
the
tall
Cylinder
of
Mercury
be
of
the
usual
or
former
height
,
as
we
have
found
it
,
't
will
appear
congruous
to
our
Hypothesis
,
that
the
weight
of
the
external
Air
may
exercise
as
much
Pression
upon
the
stagnant
Mercury
through
a
little
hole
,
as
when
all
the
upper
Superficies
of
that
Mercury
was
directly
expos'd
to
it
.
And
if
one
have
not
the
conveniency
to
draw
out
the
shorter
Leg
as
is
prescrib'd
,
one
may
nevertheless
make
the
Tryal
,
by
carefully
stopping
up
the
Orifice
with
a
Cork
and
Cement
,
leaving
onely
(
or
afterwards
making
)
a
very
small
hole
for
the
Air
to
pass
in
and
out
.
If
I
had
not
wanted
a
fit
Instrument
,
I
would
have
tried
to
exemplifie
the
Truth
of
what
has
been
delivered
,
by
adding
to
the
Glasses
we
imploy'd
to
make
the
Vᵗʰ
.
Experiment
,
such
a
Cover
,
as
might
be
cemented
on
to
the
Edge
of
the
Glass
,
having
onely
a
very
small
hole
in
the
midst
,
at
which
the
Atmosphere
would
be
reduc'd
to
exercise
its
Pressure
;
and
the
like
Cover
I
would
have
made
use
of
in
the
Xth
Experiment
,
about
the
breaking
of
Glass-plates
in
the
unexhausted
Receiver
,
by
the
bare
Spring
of
the
Air.
EXPERIMENT
XXV
.
Shewing
that
an
Oblique
pressure
of
the
Atmosphere
may
suffice
to
keep
up
the
Mercury
at
the
wonted
height
in
the
Torricellian
Experiment
,
and
that
the
Spring
of
a
little
included
Air
may
do
the
same
.
BY
adding
a
couple
of
little
Circumstances
to
the
Tryals
lately
propos'd
,
we
may
confirm
two
considerable
Articles
of
our
Hypothesis
.
For
1.
if
,
in
stead
of
drawing
the
shorter
Leg
of
our
Barometrical
Syphon
(
if
I
may
so
call
it
)
directly
upwards
,
or
parallel
to
the
longer
Leg
as
in
the
foregoing
Experiment
,
You
make
the
slender
part
bend
off
so
,
as
that
,
if
it
were
continued
,
it
would
make
a
right
Angle
with
the
longer
Leg
of
the
Syphon
,
or
else
an
acute
Angle
tending
downwards
;
this
being
done
,
I
say
,
if
when
the
Tube
is
erected
the
Mercury
rest
at
its
wonted
station
,
't
will
appear
,
that
the
Pressure
of
the
Atmosphere
may
be
exercis'd
upon
it
as
well
obliquely
,
when
the
Pipe
that
conveyes
it
is
either
Horizontal
,
or
opens
downwards
.
And
2.
if
in
stead
of
bending
this
slender
Pipe
,
one
seal
it
up
Hermetically
,
the
continuance
of
the
Mercurial
Cylinder
at
the
same
height
will
shew
,
that
the
Spring
of
a
very
litle
Air
,
shut
up
with
the
Presure
of
the
Atmosphere
upon
it
,
(
though
no
more
than
what
the
Air
here
below
is
ordinarily
expos'd
to
by
the
weight
of
the
incumbent
Air
,
)
is
able
to
support
as
tall
a
Cylinder
of
Mercury
as
the
weight
of
the
whole
Atmosphere
,
i.
e.
of
as
much
of
it
,
as
can
come
to
exercise
its
Pressure
against
the
Mercury
.
NB.
If
when
the
shorter
Leg
of
the
Baroscope
is
seal'd
up
,
you
move
the
Instrument
up
and
down
,
the
Mercury
will
vibrate
,
by
reason
of
the
somewhat
yielding
Spring
of
the
imprisoned
Air
;
but
because
of
the
resistance
of
the
Spring
,
the
motion
will
be
diversified
after
an
odde
and
pretty
manner
:
which
may
be
easily
perceiv'd
by
the
Impression
it
makes
upon
the
Hand
,
but
not
so
easily
describ'd
.
And
because
that
,
when
the
shorter
Leg
is
drawn
out
slender
enough
,
after
the
Instrument
is
furnish'd
with
Quick-silver
,
t
is
easie
to
seal
it
up
with
the
flame
of
a
Candle
,
without
the
help
of
any
Instrument
at
all
,
I
shall
here
take
notice
to
Your
Lorship
,
(
which
I
could
not
reasonably
do
before
,
)
that
it
may
on
some
occasions
be
convenient
to
seal
up
the
Barometer
,
before
it
be
transported
,
and
,
in
some
cases
,
to
incline
the
Tube
beforehand
,
till
the
Quick-silver
have
quite
fill'd
the
longer
Leg
;
by
this
means
the
vibrations
of
the
Quick-silver
will
be
less
than
otherwise
they
would
be
,
and
't
will
be
no
trouble
at
all
,
when
the
Instrument
is
brought
to
the
design'd
place
,
to
break
off
the
slender
Apex
of
the
shorter
Leg
,
and
so
expose
again
the
Mercury
to
the
Pressure
of
the
Atmosphere
.
As
about
the
former
Experiments
,
so
about
these
two
this
Advertisement
may
be
given
;
viz.
That
the
same
Tryals
,
for
the
main
,
may
be
made
without
confining
ones
self
to
the
propos'd
wayes
of
making
them
.
1.
For
the
First
of
these
new
Tryals
may
be
made
by
Cementing
very
carefully
on
to
the
Orifice
of
the
shorter
Leg
(
which
need
not
be
alter'd
)
a
short
Pipe
of
Glass
,
whose
upper
end
may
be
drawn
out
very
slender
,
and
bent
either
Horizontally
or
downwards
;
which
is
far
easier
to
be
done
,
than
to
draw
out
the
shorter
Leg
when
the
Glass
is
furnish'd
with
Mercury
.
2.
And
as
for
the
2d
Tryal
,
that
may
be
well
enough
made
,
by
carefully
stopping
the
unalter'd
Orifice
of
the
shorter
Leg
with
a
good
Cork
,
and
our
close
Cement
,
or
with
the
later
onely
;
and
when
you
would
afterwards
use
this
Instrument
as
a
Baroscope
,
You
need
but
heat
a
Pin
or
slender
Wire
red
hot
,
and
so
burn
a
hole
through
the
Stoppel
.
And
this
Expedient
,
which
I
could
not
conveniently
advertise
Your
Lordship
of
sooner
,
may
be
of
Use
when
a
Travailing
Baroscope
is
to
be
often
remov'd
:
because
having
once
stopt
the
whole
Orifice
well
,
t
is
far
more
easie
to
stop
and
open
a
Pin-hole
accurately
,
than
to
close
and
unstop
the
whole
Orifice
of
the
Tube
.
Note
,
I
endeavoured
to
confirm
more
than
one
of
the
foregoing
Particulars
by
this
one
Experiment
.
Having
caus'd
a
Portable
Barometer
to
be
made
with
the
shorter
Leg
of
a
somewhat
more
than
ordinary
length
,
I
afterwards
caus'd
the
upper
part
of
this
Leg
to
be
drawn
out
very
slender
,
(
as
in
this
25th
Experiment
;
)
and
lastly
I
caus'd
the
same
shorter
Leg
to
be
either
about
or
somewhat
above
the
middle
bended
downwards
,
so
that
the
small
Orifice
of
the
slender
Apex
pointed
towards
the
Ground
.
This
done
,
I
was
to
have
measur'd
the
height
of
the
suspended
Mercury
,
but
not
having
a
fit
Ruler
at
hand
,
I
then
deferr'd
,
and
afterwards
forgot
to
do
it
;
but
I
remember
,
that
neither
I
,
nor
some
others
vers'd
in
such
Experiments
,
to
whom
I
shew'd
it
,
took
any
notice
that
the
Mercury
was
less
high
than
in
ordinary
Barometers
;
whence
't
was
concluded
,
that
the
Atmosphere
could
exercise
his
Pressure
not
onely
at
a
very
small
Orifice
,
(
which
in
our
Experiment
did
litle
,
if
at
all
,
exceed
a
Pin-hole
,
)
but
when
the
Air
must
at
this
little
Orifice
press
upwards
to
be
able
to
press
upon
the
Surface
of
the
stagnant
Mercury
:
EXPERIMENT
XXVI
.
About
the
making
of
a
Baroscope
(
but
of
litle
practical
use
)
that
serves
but
at
certain
times
.
TO
shew
some
Ingenious
men
by
a
Medium
,
that
has
not
hitherto
(
that
I
know
of
)
been
made
use
of
,
That
the
not
subsiding
of
Quick-silver
in
an
inverted
Tube
,
that
is
a
little
shorter
than
30
inches
,
or
thereabouts
,
does
not
proceed
from
such
a
fuga
Vacui
as
the
Schools
ascribe
to
Nature
,
but
from
the
Gravity
of
the
external
Air
,
I
devised
the
following
Experiment
.
Having
made
choice
of
a
time
,
when
it
appear'd
by
a
good
Baroscope
,
(
which
I
had
frequently
consulted
for
that
purpose
,
)
that
the
Atmosphere
was
considerably
heavy
,
I
caus'd
Galspipe
,
Hermetically
seal'd
at
one
end
,
and
in
length
about
2
foot
and
a
half
,
to
be
fill'd
with
Quick-silver
,
save
a
very
litle
wherein
some
drops
of
Water
were
put
,
that
we
might
the
better
discern
the
Bubbles
,
if
any
should
be
left
after
the
inversion
of
the
Tube
into
an
open
Glass
with
stagnant
Mercury
in
it
.
Having
by
this
means
(
though
not
without
difficulty
)
freed
the
Tube
from
bubbles
,
we
so
order'd
the
matter
,
that
the
Quick-silver
and
the
litle
water
that
was
about
it
,
fill'd
the
Tube
exactly
,
without
leaving
any
interval
that
we
could
discern
at
the
top
,
and
yet
the
Mercurial
Cylinder
was
but
very
little
higher
than
that
of
our
Baroscope
was
at
that
time
.
This
done
,
the
newly
fill'd
Pipe
was
left
erected
in
a
quiet
place
,
where
the
Liquors
retain'd
their
former
height
for
divers
dayes
.
But
though
an
ordinary
School-Philosopher
would
confidently
have
attributed
this
sustation
of
so
heavy
a
Body
to
Nature's
fear
of
admitting
a
Vacuum
,
yet
it
seems
,
that
either
she
is
not
alwayes
equally
subject
to
that
fear
,
or
some
other
cause
of
the
Phaenomenon
must
be
assign'd
;
for
when
(
a
pretty
while
after
)
I
had
observ'd
by
the
Baroscope
,
that
the
Atmosphere
was
grown
much
lighter
than
before
,
repairing
to
my
short
Tube
,
I
found
that
according
to
my
expectation
the
Quick-silver
was
not
inconsiderably
subsided
,
and
had
left
a
Cavity
at
the
top
,
which
afterwards
grew
lesser
,
according
as
the
Atmosphere
grew
heavier
.
NB.
1.
The
Tube
imployed
about
this
Experiment
,
may
be
brought
to
the
requisite
shortness
,
either
by
wearing
off
a
little
of
the
Glass
at
the
Orifice
of
it
,
or
by
increasing
the
height
of
the
stagnant
Mercury
,
into
which
it
hath
been
inverted
.
2.
When
the
Quick
silver
in
our
short
Tube
was
much
subsided
,
there
appeared
in
the
Water
that
swam
upon
it
a
litle
Bubble
,
about
the
bigness
of
a
small
Pins
head
,
but
,
considering
how
careful
we
had
been
to
free
the
Tube
from
bubbles
before
we
set
it
to
rest
,
it
may
very
well
be
,
that
this
so
small
a
Bubble
was
not
produc'd
till
after
the
subsiding
of
the
Quick-silver
,
whereupon
the
Aerial
Particles
in
the
Water
became
less
compress'd
than
before
;
not
to
mention
that
the
Bubble
(
such
as
it
was
)
appear'd
very
much
greater
than
it
would
have
done
,
if
the
Pressure
of
the
Atmosphere
had
not
been
kept
from
it
by
the
weight
of
the
subjacent
pillar
of
Mercury
.
EXPERIMENT
XXVII
.
About
the
Ascension
of
Liquors
in
very
slender
Pipes
in
an
Exhausted
Receiver
.
VVHat
I
related
to
Your
Lordship
in
the
35th
of
the
publish'd
Experiments
,
(
pag.
138.
)
about
the
seemingly
spontaneous
Ascension
of
Water
in
slender
Pipes
,
has
occasion'd
the
making
of
many
Tryals
by
the
Curious
,
whereby
that
Experiment
has
been
not
a
little
diversify'd
;
but
because
among
those
I
have
yet
heard
of
none
have
been
made
in
our
Engine
,
it
may
not
be
amiss
to
adde
the
following
Tryal
,
which
may
be
of
use
in
the
Examen
of
one
or
two
of
the
chief
Conjectures
that
have
hitherto
been
propos'd
about
the
cause
of
that
odde
phaenomenon
.
We
ting'd
some
spirit
of
Wine
with
Cocheneel
,
which
being
put
into
the
Receiver
,
and
the
Air
withdrawn
,
did
exceedingly
bubble
for
a
pretty
while
.
Then
little
hollow
Pipes
of
differing
Sizes
being
put
into
it
,
the
red
Liquor
ascended
higher
in
the
slenderer
than
the
others
,
but
upon
the
withdrawing
of
the
Air
there
scarce
appear'd
any
sensible
difference
in
the
heights
of
the
Liquor
,
nor
yet
upon
the
letting
it
in
again
.
Afterwards
two
such
Pipes
of
differing
Sizes
,
being
fasten'd
together
(
at
a
distance
)
with
Cement
,
were
let
down
into
the
same
spirit
of
Wine
when
the
Receiver
was
well
exhausted
,
notwithstanding
which
the
Liquor
ascended
in
them
,
for
ought
we
could
plainly
see
,
after
the
ordinary
manner
;
onely
when
the
Air
was
let
in
again
,
there
seem'd
to
be
some
little
(
and
but
very
litle
)
rising
at
least
in
one
of
the
Pipes
.
In
this
Tryal
this
Phaenomenon
was
noted
:
That
though
there
appear'd
no
Bubbles
at
all
in
the
vessel'd
spirit
of
Wine
,
(
notwithstanding
that
we
continued
to
pump
,
)
yet
there
did
for
a
pretty
while
arise
bubbles
in
that
part
of
the
Liquor
that
was
got
into
the
slender
Pipes
;
which
I
guess'd
to
proceed
from
the
sustentation
(
in
part
)
of
the
spirit
of
Wine
,
made
by
the
inside
of
the
Pipe
whereto
it
adher'd
.
EXPERIMENT
XXVIII
.
About
the
great
and
seemingly
spontaneous
Ascension
of
Water
in
a
Pipe
fill'd
with
a
compact
body
,
whose
Particles
are
thought
incapable
of
imbibing
it
.
VPon
occasion
of
the
(
seemingly
)
spontaneous
Ascension
of
Water
in
slender
Pipes
of
Glass
,
I
consider'd
that
't
would
be
easie
by
another
way
to
make
it
rise
to
a
far
Greater
height
than
hitherto
had
been
done
;
for
since
we
had
found
by
Observation
that
,
caeteris
paribus
,
the
slenderer
the
little
Pipes
were
that
we
imployed
,
the
higher
the
Liquor
would
rise
in
them
;
and
since
the
Hydrostaticks
had
taught
us
,
that
often
times
even
in
very
crooked
Pipes
Water
would
be
made
to
ascend
by
the
same
wayes
(
of
raising
it
)
to
the
same
perpendicular
height
(
or
thereabouts
)
as
in
straight
ones
;
I
thought
,
that
I
might
well
substitute
a
Powder
,
consisting
of
solid
Corpuscles
heap'd
upon
one
another
,
and
included
in
a
Glass-Cane
in
stead
of
the
litle
Pipes
I
had
hitherto
used
.
For
I
consider'd
the
litle
intervals
,
that
would
necessarily
be
left
between
these
differingly
shap'd
and
confusedly
plac'd
Corpuscles
,
would
allow
passage
to
the
Water
as
did
the
Cavities
of
the
little
Pipes
,
and
yet
would
in
many
places
be
straiter
than
the
slenderest
Pipes
I
had
us'd
.
And
though
beaten
Glass
,
or
fine
Sand
,
&c.
might
have
been
imployed
about
this
Experiment
,
yet
I
judg'd
it
far
more
convenient
to
make
use
of
some
Metalline
Calx
,
because
the
Operation
of
the
Fire
,
making
a
more
exquisite
Comminution
of
Solid
bodies
than
our
Pestles
are
wont
to
do
,
is
fit
to
supply
us
with
exceeding
minute
Granes
,
that
intercept
proportionable
Cavities
between
them
.
Upon
this
Consideration
therefore
(
besides
others
to
be
hereafter
hinted
)
I
took
a
strait
pipe
of
Glass
,
open
at
both
ends
,
and
of
a
moderate
wideness
,
(
for
it
need
not
be
very
slender
,
)
and
having
tyed
a
Linnen-rag
to
one
end
of
it
,
that
the
Water
might
have
free
passage
in
,
and
the
Powder
not
be
able
to
fall
out
,
we
carefully
and
as
exactly
as
we
could
,
fill'd
the
Cavity
with
Minium
,
(
which
is
Lead
calcin'd
,
without
addition
,
to
Redness
;
)
and
then
having
erected
the
Tube
,
so
that
the
bottom
of
it
rested
upon
that
of
a
somewhat
shallow
and
open
mouth'd
Glass
,
containing
Water
enough
to
swim
an
Inch
or
two
above
the
bottom
of
the
Tube
;
Wherefore
taking
afterwards
another
Tube
,
and
some
Minimum
carefully
prepared
,
I
prosecuted
the
Experiment
so
as
to
make
the
Water
rise
in
the
Pipe
about
40
inches
above
the
surface
of
the
stagnant
Water
;
and
I
guess'd
it
had
risen
higher
,
but
,
by
reason
that
at
the
upper
part
of
the
Minimum
the
difference
of
colour
was
so
small
,
as
not
to
be
easily
distinguishable
with
certainty
,
I
forbore
to
allow
a
greater
height
to
the
Ascension
of
the
Water
:
nor
could
I
,
where
I
then
was
,
much
promote
the
Experiment
,
for
want
of
such
Accommodations
as
I
desir'd
;
but
about
the
Experiment
,
as
I
try'd
it
,
I
shall
take
notice
of
the
following
particulars
.
I
tryed
some
other
Powders
besides
red
Lead
,
(
as
beaten
Glass
,
pieces
of
fine
Spunge
,
Putty
,
&c.
)
but
did
not
find
any
of
them
do
so
well
;
which
success
was
yet
perhaps
but
accidental
,
and
therefore
the
Tryal
may
be
repeated
,
especially
with
Putty
,
because
that
being
a
Metalline
Calx
as
well
as
Minium
,
consists
of
very
small
Grains
,
and
by
reason
of
its
Great
whiteness
receives
a
Greater
change
of
colour
by
wetting
than
Minium
does
;
in
which
,
especially
if
it
be
very
fine
,
the
discoloration
that
Water
makes
toward
the
upper
part
of
the
Tube
,
is
sometimes
not
so
easie
to
be
clearly
discern'd
.
2.
I
did
indeed
endeavour
to
remedy
this
inconvenience
,
by
using
,
in
stead
of
meer
Water
,
tincted
Liquors
,
as
Ink
,
tincture
of
Safron
,
&c.
but
they
seem'd
not
to
rise
near
so
high
as
Water
alone
,
as
if
the
dissolv'd
ingredients
did
by
degrees
choak
the
pores
of
the
Minium
.
3.
To
have
the
Grains
of
our
Powder
more
minute
and
the
smaller
intervals
between
them
,
I
chose
not
onely
to
use
the
finest
sort
of
Minium
I
could
procure
,
but
also
to
sift
it
through
a
very
fine
Searce
,
and
to
put
it
but
by
litle
and
litle
into
the
Tube
,
that
by
ramming
it
from
time
to
time
it
might
be
made
to
lie
the
closer
;
which
Expedients
succeeded
not
ill
.
4.
It
seem'd
by
a
Tryal
or
two
(
for
I
am
not
sure
the
observation
will
alwayes
hold
,
)
that
if
the
Tube
were
very
slender
,
(
as
about
the
bigness
of
a
Swans
quill
,
)
the
Experiment
succeeded
not
well
.
5.
It
may
be
worth
while
to
observe
in
what
times
the
Water
ascends
to
such
and
such
heights
;
for
at
the
beginning
t
will
ascend
much
faster
then
afterwards
,
and
sometimes
t
will
continue
rising
24
or
30
hours
,
and
sometimes
perhaps
much
longer
.
6.
One
of
the
scopes
I
propos'd
to
my self
in
this
Experiment
was
to
discover
a
mistake
in
the
Explication
that
some
Learned
modern
Writers
have
given
us
of
the
cause
of
Filtration
;
for
whereas
they
teach
that
the
parts
of
Filtre
that
touch
the
Water
,
being
swell'd
by
the
ingress
of
it
to
their
pores
,
are
thereby
made
to
lift
up
the
Water
,
till
it
touch
the
superiour
parts
of
the
Filtre
that
are
almost
contiguous
to
them
;
by
which
means
these
being
also
wetted
,
and
swell'd
,
raise
the
Water
to
the
other
neighbouring
parts
of
the
Filtre
,
till
it
have
reacht
to
the
top
of
it
,
whence
it
s
own
Gravity
will
make
it
descend
.
But
in
our
case
we
have
a
Filtre
made
of
solid
Metalline
Corpuscles
,
where
t
will
be
very
hard
to
shew
that
any
such
intumescence
is
produc'd
,
as
the
recited
Explication
requires
.
7.
Water
ascends
so
few
inches
even
in
very
slender
Pipes
,
as
to
seem
much
to
favour
their
Judgment
,
who
dissallow
the
conjecture
lately
entertain'd
by
some
ingenious
men
,
(
particularly
Mr
H.
)
about
the
raising
of
the
Sap
in
Trees
after
the
like
manner
that
Water
is
raised
in
slender
Pipes
;
but
without
fully
delivering
yet
my
thoughts
of
that
Speculation
,
I
may
take
notice
,
that
in
the
last
Tryal
above
recited
,
I
made
Water
to
ascend
near
,
if
not
above
,
3
foot
½
and
if
by
so
sleight
an
Expedient
,
Water
may
be
made
to
rise
as
high
as
is
necessary
for
the
Nutrition
of
some
thousands
of
Plants
,
(
for
such
a
number
there
is
,
that
exceed
not
3
foot
1/2
in
height
,
)
one
may
without
absurdity
ask
,
why
t
is
not
possible
that
Nature
,
or
rather
the
most
wise
Author
of
it
,
may
have
made
such
Contrivances
in
Plants
,
as
to
make
Liquors
ascend
in
them
to
the
Tops
of
the
tallest
Trees
;
especially
since
,
besides
divers
things
that
we
may
already
suspect
,
(
as
Heat
,
and
something
equivalent
to
well
plac'd
Valves
,
)
many
others
,
that
perhaps
are
not
yet
dreamt
of
,
may
probably
concur
to
the
Effect
.
8.
As
I
formerly
made
,
by
bending
the
slender
Pipes
we
have
been
talking
of
,
short
Syphons
through
which
the
Water
runs
,
without
being
at
first
assisted
by
Suction
,
so
I
thought
fit
to
try
,
whether
I
could
not
in
larger
Pipes
,
by
the
help
of
Minium
,
make
much
longer
Syphons
.
But
though
when
the
Orifices
were
turn'd
upwards
,
fine
Minium
were
ramm'd
into
both
the
Legs
,
and
the
Orifices
were
both
of
them
clos'd
,
yet
when
they
came
to
be
again
turn'd
downwards
,
the
weight
of
the
Minium
would
somewhere
or
other
(
and
for
the
most
part
at
or
near
the
flexure
)
make
some
such
chink
or
discontinuation
,
as
to
hinder
the
farther
progress
of
the
Water
.
Which
impediment
,
though
I
judg'd
it
superable
enough
,
(
especially
by
making
at
the
Flexure
a
little
Pipe
or
Socket
,
by
which
both
Legs
might
be
closely
fill'd
)
yet
for
want
of
Accommodations
and
leisure
it
was
left
unsurmounted
.
Upon
which
account
also
I
did
not
satisfie
my self
about
the
success
of
some
former
Tryals
,
as
of
the
Ascension
of
Water
into
pieces
of
Wood
of
differing
sorts
,
the
operation
of
the
Vicissitudes
of
the
Suns
beams
,
and
the
absence
of
them
upon
liquors
ascending
in
Tubes
fill'd
with
Minium
,
&c.
9.
Whether
the
Pressure
of
the
outward
Air
be
the
cause
of
the
Ascension
of
Liquors
in
our
Tubes
furnisht
with
Minium
,
is
a
Probleme
,
in
order
to
whose
Solution
I
could
acquaint
Your
Lordship
with
a
Contrivance
,
wherewith
to
make
some
Tryals
in
our
Engine
.
But
since
it
can
scarce
be
well
describ'd
without
many
words
,
unless
You
express
a
particular
Curiosity
to
know
it
,
I
shall
not
trouble
You
with
it
:
and
the
rather
,
because
the
best
way
I
know
of
examining
this
difficulty
belongs
to
the
2d
part
of
this
Continuation
,
where
mention
is
made
of
an
attempt
about
it
,
which
did
not
,
I
confess
,
displease
me
.
EXPERIMENT
XXIX
.
Of
the
seemingly
spontaneous
Ascension
of
Salts
along
the
sides
of
Glasses
,
with
a
conjecture
at
the
Cause
of
it
.
TO
the
same
Cause
(
or
the
like
)
with
that
of
the
Ascension
of
Water
in
slender
Pipes
may
be
probably
referr'd
an
odde
Phaenomenon
,
which
though
I
remember
not
to
have
been
mentioned
by
any
Chymical
or
other
Writer
,
I
have
not
unfrequently
observed
as
well
by
chance
as
in
Tryals
purposely
made
to
satisfie
my self
and
others
about
the
truth
of
it
.
The
Phaenomenon
,
in
short
,
was
this
.
That
having
in
wide-mouth'd
Glasses
(
which
should
not
be
very
deep
)
expos'd
to
the
Air
a
strong
Solution
of
common
Sea-salt
or
of
Vitriol
,
which
reacht
not
by
some
inches
to
the
top
of
the
Glass
;
and
having
suffered
much
of
the
aqueous
part
to
exhale
away
very
slowly
,
the
coagulated
Salt
would
at
length
appear
to
have
lin'd
the
inside
of
the
Glass
,
and
to
have
ascended
much
higher
,
not
onely
than
the
place
where
the
surface
of
the
remaining
Water
then
rested
at
,
but
than
the
place
to
which
the
Liquor
reacht
when
't
was
first
poured
in
.
And
if
the
Experiment
were
continued
long
enough
,
I
sometimes
observed
this
Ascension
of
the
Salt
to
amount
to
some
inches
,
and
that
the
salt
did
not
onely
line
the
inside
of
the
Glass
,
but
,
getting
over
the
brim
of
it
,
cover'd
the
outside
of
it
with
a
Saline
Crust
:
which
made
them
that
saw
how
litle
liquor
remain'd
in
the
Glass
,
admire
how
it
could
possibly
get
thither
.
And
though
I
have
mentioned
but
the
Solution
of
Vitriol
and
Sea-salt
,
because
they
are
much
easier
than
others
to
be
procur'd
,
and
yet
the
Experiment
succeeds
better
in
Them
than
in
some
other
far
less
parable
Salts
;
yet
they
are
not
the
onely
ones
by
whose
Solutions
the
recited
Phaenomenon
may
be
Exhibited
.
As
for
the
Cause
of
this
odd
Effect
,
though
I
shall
not
propose
any
thing
about
it
with
Confidence
,
till
I
have
further
inquired
into
it
,
and
especially
till
I
have
tryed
whether
the
Phaenomenon
may
be
produced
in
an
Exhausted
Receiver
;
yet
,
by
what
I
have
hitherto
observed
,
I
am
inclin'd
to
conjecture
,
that
it
may
be
referr'd
to
such
a
cause
as
that
of
the
Ascension
of
Liquors
in
Pipes
after
some
such
manner
as
this
.
First
,
I
observed
,
that
in
Water
and
Aqueous
liquors
,
that
part
of
the
Surface
which
is
next
the
sides
of
the
Glass
,
is
(
whatever
the
reason
of
it
be
)
sensibly
more
elevated
than
the
rest
of
the
Superficies
;
and
if
very
litle
clippings
of
Straw
or
other
such
minute
and
light
bodies
,
floating
upon
the
Water
,
chance
to
approach
near
enough
to
the
sides
of
the
Glass
,
they
will
be
apt
(
which
one
would
not
expect
)
to
run
up
as
t
were
this
ascent
of
Water
,
and
rest
against
the
sides
of
the
Glass
.
Next
we
may
take
notice
with
the
Salt-boylers
and
Chymists
,
that
Sea-salt
is
usually
wont
to
coagulate
at
the
top
of
the
Water
in
small
and
oblong
Corpuscles
,
so
that
as
to
these
t
is
easie
to
conceive
,
to
them
that
have
considered
the
first
Observation
,
how
numbers
of
them
may
fasten
themselves
round
about
to
the
inside
of
the
Glass
.
And
besides
Sea-salt
,
I
have
found
by
tryal
divers
others
,
if
their
Solutions
be
slowly
enough
evaporated
,
that
will
,
whilst
yet
there
remains
a
good
proportion
of
Liquor
,
afford
Saline
Concretions
at
the
top
of
the
Water
.
And
the
fastning
of
Saline
particles
to
the
sides
of
the
Glass
may
perhaps
be
promoted
by
the
Coldness
that
may
be
communicated
to
the
Corpuscles
contiguous
to
the
Glass
,
by
reason
of
the
coldness
which
the
Glass
may
be
suspected
to
have
,
upon
the
score
of
its
Density
,
in
comparison
of
Water
.
But
to
proceed
:
I
consider
,
that
by
the
Evaporation
of
the
aqueous
parts
of
the
Solution
,
the
surface
of
the
remaining
liquor
must
necessarily
subside
,
and
those
Saline
particles
,
that
were
contiguous
to
the
inside
of
the
Glass
and
the
more
elevated
part
of
the
Water
,
having
no
longer
enough
of
Liquor
to
keep
them
dissolv'd
,
will
be
apt
to
remain
sticking
to
the
sides
of
the
Glass
,
and
upon
the
least
farther
Evaporation
of
the
Water
will
be
a
litle
higher
than
the
greater
part
of
the
Superficies
of
that
Liquor
;
by
which
means
it
will
come
to
pass
,
that
,
by
reason
of
the
litle
inequalities
that
will
be
on
the
internal
surface
of
the
adhering
Corpuscles
of
the
Salt
,
and
perhaps
also
on
the
internal
Superficies
of
the
Glass
,
there
will
be
intercepted
between
the
Salt
and
the
Glass
litle
Cavities
,
into
which
the
Water
contiguous
to
the
bottom
will
ascend
or
be
impell'd
upon
such
an
account
as
that
,
whereon
t
is
rais'd
in
slender
Pipes
.
And
when
the
Liquor
is
thus
got
to
the
top
of
the
Salt
,
and
comes
to
be
exposed
to
the
Air
,
the
Saline
part
may
,
by
the
evaporation
of
the
Aqueous
,
be
brought
to
coagulate
there
,
and
consequently
to
increase
the
height
of
the
Saline
filme
,
(
if
I
may
so
call
it
;
)
which
by
the
like
means
may
be
at
length
brought
to
reach
to
the
very
top
of
the
Glass
,
whence
it
may
easily
be
brought
over
to
the
outside
of
the
vessel
,
where
the
natural
weight
of
the
Solution
will
facilitate
its
progress
downwards
;
and
the
skin
of
Salt
,
together
with
the
contiguous
surface
of
the
Glass
,
may
(
at
length
)
constitute
a
kind
of
Syphon
.
To
this
Explication
it
agrees
well
,
that
I
have
usually
observed
the
Saline
filme
hitherto
mentioned
to
be
with
great
ease
separable
from
the
Glass
in
large
Fleaks
;
which
argues
,
that
they
did
not
stick
close
to
one
another
except
in
some
few
places
,
but
had
a
thin
Cavity
intercepted
between
them
,
through
which
the
water
might
ascend
.
Nor
is
it
repugnant
to
this
Explication
,
that
in
case
the
Water
ascended
,
it
should
,
as
it
seems
,
dissolve
the
Salt
.
For
the
Liquor
being
already
upon
the
point
of
Concretion
,
is
so
glutted
with
Salt
,
that
it
can
dissolve
no
more
.
Whence
we
may
also
render
a
reason
,
why
,
when
the
Saline
filme
chances
to
reach
to
the
outside
of
the
Glass
,
the
Liquor
(
divers
times
)
does
not
run
down
to
the
bottom
,
but
is
coagulated
by
the
way
.
And
I
have
also
had
a
suspicion
,
(
though
I
could
not
seasonably
take
notice
of
it
before
now
,
)
that
when
the
Concretion
is
once
begun
,
the
Film
may
be
raised
and
propagated
,
not
onely
by
the
motion
of
the
Liquor
between
the
inside
of
it
and
the
Glass
,
but
by
the
same
Liquor
's
insinuating
it self
on
the
outside
of
the
Film
into
the
small
Chinks
and
Crevises
,
intercepted
between
the
Saline
Corpuscles
,
as
Ink
(
especially
if
somewhat
thin
)
rises
into
the
Slit
,
and
along
the
sides
of
the
Nib
of
a
Pen
,
though
nothing
but
its
very
point
be
dipt
in
the
surface
of
the
liquor
.
And
by
this
means
the
impregnated
Solution
may
as
it
were
climb
up
to
the
top
of
the
saline
Concretion
,
and
by
coagulating
there
adde
to
its
height
.
Some
other
Circumstances
I
have
noted
of
our
Phaenomenon
,
that
agree
with
the
propos'd
Explication
,
but
perhaps
it
would
not
be
worth
while
to
spend
more
time
about
it
.
Not
to
examine
here
whether
what
has
been
related
,
so
as
to
make
it
probable
that
ascending
Water
may
carry
up
wherewithall
to
heighten
and
increase
the
Pipes
or
vessels
through
which
it
rises
,
may
contribute
any
thing
more
then
was
suggested
in
the
former
28th
Experiment
,
towards
the
Explication
of
the
Rising
and
diffusing
of
the
Sap
in
Trees
.
EXPERIMENT
XXX
.
About
an
attempt
to
measure
the
Gravity
of
Cylinders
of
the
Atmosphere
,
so
as
that
it
may
be
exprest
by
known
and
common
Weights
.
VVHilst
I
was
making
the
former
Experiments
,
't
was
more
than
once
my
wish
,
that
by
knowing
the
just
weight
of
a
Cylinder
of
Quick-silver
of
a
determinate
Diameter
,
and
of
29
or
30
inches
high
,
which
is
near
the
height
that
the
Air
does
usually
counterballance
,
I
might
the
better
estimate
the
weight
of
a
Cylinder
of
the
Atmosphere
of
that
Diameter
,
and
consequently
make
the
better
Guesses
how
near
the
effects
of
the
Spring
of
the
Air
(
as
well
as
of
its
Weight
,
)
produc'd
by
the
help
of
our
Engine
,
approach'd
to
the
utmost
of
what
might
have
been
expected
,
in
case
all
the
instruments
imployed
had
been
perfect
,
and
all
concurrent
circumstances
had
been
favourable
:
And
upon
this
account
I
several
times
regretted
my
want
of
a
long
Instrument
of
Steel
or
hardned
Iron
,
wherewith
I
many
years
since
made
an
Observation
,
that
was
more
carefully
registred
than
preserved
,
of
the
weight
of
a
Mercurial
Cylinder
of
a
determinate
height
as
well
as
Diameter
;
which
weight
I
did
not
think
it
so
safe
to
determine
by
the
help
of
Glass-Tubes
,
because
t
is
very
difficult
to
have
them
uniformly
Cylindrical
,
and
to
know
that
they
are
so
,
in
regard
that
they
are
form'd
but
by
blowing
and
drawing
out
,
and
,
besides
the
inequality
that
may
happen
to
the
Cavity
upon
other
accounts
,
t
is
very
difficult
to
make
the
sides
of
the
Glass
equally
thick
,
and
to
examine
whether
they
be
so
or
no.
But
at
length
lighting
upon
(
what
I
had
too
often
wanted
in
the
foregoing
Experiments
)
a
dexterous
Artificer
,
that
chanced
to
come
for
a
while
to
the
place
where
I
then
was
,
I
indeavour'd
to
repair
my
loss
,
as
well
as
he
could
help
me
to
do
it
,
by
causing
him
to
turn
very
carefully
a
Cylindrical
piece
of
Brass
,
of
an
inch
in
Diameter
,
and
3
inches
in
length
,
and
open
(
that
it
might
be
the
better
wrought
)
at
both
ends
,
to
one
of
which
was
exactly
fitted
a
flat
bottom
of
the
same
Metal
,
fastned
very
close
to
it
with
little
Screws
on
the
outside
;
this
being
judg'd
a
better
way
,
than
if
it
had
been
turn'd
all
of
a
piece
:
This
instrument
being
diligently
counterpois'd
in
a
trusty
pair
of
Scales
,
was
carefully
fill'd
with
Mercury
,
which
(
for
greater
caution
)
we
took
out
of
a
new
parcel
,
that
we
had
not
yet
imployed
about
other
Experiments
,
and
finding
it
to
weigh
XVII
Ounces
,
one
Dram
,
45
Gr:
Troy
weight
,
(
or
137
dr:
45
gr:
)
multiplying
that
by
10
,
there
will
come
for
the
weight
of
a
Mercurial
Cylinder
,
of
one
inch
in
Diameter
,
and
30
inches
in
height
,
(
and
so
high
I
have
divers
times
seen
the
Mercury
to
be
in
a
good
Barometer
,
)
about
14
,
2l
,
(
i.e.
14l
,
2
Ounces
,
and
above
three
drams
,
Troy-weight
;
and
almost
11
,
8l
.
Haberdupoise
weight
,
(
i.e.
11l
,
12
Ounces
,
and
above
6
Drams
,
)
which
is
a
greater
weight
than
without
such
a
Tryal
one
would
easily
imagine
that
so
short
a
Cylinder
of
Mercury
,
and
much
less
that
a
Cylinder
of
so
light
a
Body
as
Air
,
being
neither
of
them
above
an
Inch
Diameter
,
could
amount
to
.
Note
First
,
to
examine
at
the
same
time
the
weight
of
the
Mercury
,
and
its
proportion
to
Water
,
we
did
,
before
the
Mercury
was
pour'd
into
the
Brass-vessel
,
fill
it
with
Water
,
(
after
which
we
wip'd
it
dry
before
the
Mercury
was
put
into
it
;
)
and
this
liquor
weighing
10
drams
,
and
15
gr:
the
proportion
between
the
Mercury
and
the
Water
appeard
to
be
that
of
13
18/41
to
1
:
which
though
it
seem
somewhat
of
the
least
,
yet
Your
Lordship
may
remember
,
that
I
formerly
told
You
I
had
several
times
found
the
receiv'd
proportion
of
14
to
1
,
between
Mercury
and
Water
,
to
be
somewhat
too
great
;
and
besides
that
,
in
a
vessel
whose
orifice
was
no
lesse
than
an
inch
in
Diameter
,
t
is
exceeding
difficult
to
be
sure
when
t
is
precisely
full
either
of
Water
or
Mercury
;
because
the
former
has
a
Superficies
considerably
concave
,
and
the
other
one
that
is
notably
convex
,
and
though
we
us'd
some
litle
Artifices
(
which
would
be
troublesome
here
to
mention
)
to
estimate
the
proturberance
of
the
one
liquor
,
and
the
deficience
of
the
other
,
as
near
the
truth
as
could
be
,
yet
I
am
not
sure
but
there
may
have
been
a
few
Mercurial
Corpuscles
more
than
there
should
have
been
,
and
that
consequently
some
small
abatement
may
have
been
made
of
the
weight
newly
attributed
to
the
whole
Mercurial
Cylinder
of
30
inches
.
2.
I
had
thoughts
of
making
use
of
the
Barrel
of
a
Gun
,
of
a
convenient
length
,
to
find
the
weight
of
a
Mercurial
Cylinder
of
2
foot
and
1/2
,
but
I
preferr'd
the
Instrument
already
made
use
of
(
especially
not
being
where
I
could
have
one
bored
after
a
peculiar
way
,
)
not
onely
because
I
could
not
meet
with
one
whose
Diameter
was
a
just
inch
,
and
consequently
as
convenient
for
calculations
,
and
because
that
the
Barrels
of
Guns
are
often
bor'd
a
litle
Tapering
;
but
because
a
skilful
Artificer
confest
to
me
,
that
they
scarce
ever
bore
such
Barrels
,
but
with
a
foure-square
Bit
,
(
as
they
call
it
,
)
which
leaves
the
Cavity
too
Angular
,
or
too
imperfectly
round
;
whereas
if
an
Hexahedrical
Bit
be
imploy'd
it
will
,
as
he
affirm'd
,
make
the
Cavity
almost
as
Cylindrical
as
can
be
reasonably
desired
.
I
say
nothing
here
of
making
use
for
our
purpose
of
a
Trunk
,
as
they
call
a
hollow
Cylinder
of
Wood
,
because
I
elsewhere
shew
,
that
Wood
(
at
least
such
as
the
Trunks
to
shoot
Pellets
with
are
wont
to
be
made
of
)
is
not
of
a
Texture
close
enough
for
such
an
use
.
3.
Because
in
Cylinders
of
Mercury
,
30
inches
is
a
height
which
the
Atmosphere
is
seldome
heavy
enough
to
be
able
to
counterpoise
,
and
because
29
inches
is
somewhat
nearer
the
middle
between
the
greatest
and
the
least
heights
,
at
which
I
have
observed
the
Mercury
at
differing
times
to
stand
in
good
Barometers
.
Your
Lordship
may
,
if
You
please
,
abate
a
30th
part
of
the
weight
assign'd
above
to
a
Mercurial
Cylinder
of
30
inches
,
(
though
I
take
29
and
¼
,
or
thereabouts
,
to
be
somewhat
a
more
usual
height
of
the
Mercury
,
than
precisely
Nine
and
twenty
.
)
4.
The
Weight
of
a
Mercurial
Cylinder
in
an
Aequilibrium
with
the
Atmosphere
,
and
of
one
inch
in
Diameter
being
thus
setled
,
we
may
,
by
the
help
of
the
doctrine
of
Proportions
,
and
a
few
Propositions
,
especially
the
14th
of
the
12th
book
of
Euclides
Elements
,
easily
enough
calculate
the
weight
of
a
Cylinder
of
Mercury
of
another
Diameter
,
and
consequently
the
force
of
the
Pressure
of
an
Atmospherical
Pillar
of
the
same
Diameter
.
For
since
according
to
the
forenam'd
14th
Proposition
of
the
12th
,
Cylinders
of
equal
Bases
are
to
one
another
as
their
Heights
;
and
since
by
the
2d
Proposition
of
the
same
12.
Element
,
Circles
such
as
are
the
Bases
of
Cylinders
)
are
to
one
another
,
as
the
Squares
of
their
Diameters
;
and
since
lastly
we
suppose
,
that
Mercury
being
a
Homogeneous
body
,
at
least
as
to
sense
,
the
Mercurial
Cylinders
will
have
the
same
proportion
to
each
other
in
Weight
that
they
have
in
Bulk
;
since
,
I
say
,
these
things
are
so
,
if
,
for
instance
,
we
desire
to
know
what
will
be
the
weight
of
a
Cylinder
of
30
inches
high
,
whose
Diameter
is
two
inches
,
the
Rule
will
be
this
.
As
the
square
of
the
Diameter
of
the
Standard
Cylinder
,
(
as
I
call
that
whose
weight
is
already
known
)
is
to
the
square
of
the
Diameter
of
the
Cylinder
propos'd
,
so
will
the
bulk
of
the
former
Cylinder
be
to
that
of
the
later
,
and
the
weight
of
that
to
the
weight
of
this
.
According
to
which
Rule
,
the
square
of
1
inch
(
which
is
the
Diameter
of
the
standard
Cylinder
)
being
but
1
,
(
whereby
Your
Lordship
may
perceive
how
much
the
measure
I
pitcht
on
facilitates
Computations
,
)
and
the
square
of
2
(
which
is
the
Diameter
of
the
propos'd
Cylinder
)
being
4
,
the
bulk
or
solid
Contents
of
this
later
Cylinder
,
and
consequently
its
Weight
,
will
be
4
times
as
great
as
those
of
the
standard
Cylinder
;
and
so
,
since
the
lesser
has
been
already
suppos'd
to
weigh
11
,
8l
Haberdupoise
,
the
Mercurial
Cylinder
of
two
inches
in
Diameter
,
will
weigh
47
,
2l
of
the
same
weight
.
EXPERIMENT
XXXI
.
About
the
Attractive
virtue
of
the
Loadstone
in
an
Exhausted
Receiver
.
SOme
Learned
modern
Philosophers
,
that
have
attempted
to
explicate
the
cause
and
manner
of
Magnetical
Attraction
or
Coition
,
give
such
an
account
of
it
,
as
supposes
,
that
the
Air
between
the
two
Magnetical
Bodies
,
being
driven
away
by
their
Effluviums
from
between
them
,
presses
them
on
the
parts
opposite
to
those
where
the
Contact
is
to
be
made
;
and
upon
some
such
score
(
for
I
must
not
now
stay
to
deliver
their
Theories
Circumstantially
)
the
Air
is
suppos'd
to
contribute
very
much
to
the
Attraction
and
Sustentation
of
the
Iron
by
the
Loadstone
:
wherefore
partly
to
examine
this
Opinion
,
and
partly
for
some
other
Purposes
(
not
necessary
now
to
be
mentioned
)
we
thought
fit
to
make
the
following
Exptriment
.
We
took
a
small
but
vigorous
Loadstone
,
cap'd
and
fitted
with
a
loose
plate
of
Steel
,
so
shap'd
,
that
when
it
was
sustained
by
the
Loadstone
,
we
could
hang
at
a
litle
Crook
,
that
came
out
of
the
midst
of
it
,
and
pointed
downwards
,
a
Scale
,
wherein
to
put
what
Weights
we
should
think
fit
.
Into
this
Scale
we
put
sometimes
more
and
sometimes
less
weight
,
and
then
by
shaking
of
the
Loadstone
as
much
as
we
guess'd
it
would
be
shaken
by
the
motion
of
the
Engine
,
we
found
the
greatest
weight
,
that
we
presum'd
it
would
be
able
to
support
,
in
spite
of
the
Agitation
't
would
be
exposed
to
,
which
prov'd
to
be
,
besides
the
Iron-plate
and
the
Scale
,
VI
Ounces
Troy
weight
,
to
which
if
we
added
half
an
ounce
more
,
the
whole
weight
appear'd
too
easie
to
be
shaken
off
.
This
done
,
we
hung
the
Loadstone
,
with
all
the
weight
it
sustain'd
,
at
a
Button
of
Glass
,
which
we
had
procur'd
to
be
fastned
on
to
the
top
of
the
inside
of
a
Receiver
,
when
't
was
first
blown
,
and
though
in
about
12
Exuctions
we
usually
emptied
such
Receivers
as
as
much
as
was
requisite
for
most
Experiments
;
yet
this
time
,
to
exhaust
it
the
more
accurately
,
we
continued
pumping
till
we
had
exceeded
twice
that
number
of
Exuctions
,
at
the
end
of
which
time
shaking
the
Engine
somewhat
rudely
,
without
thereby
shaking
off
the
Weight
that
hung
at
the
Loastone
,
the
Iron
seem'd
to
be
very
near
as
firmly
sustain'd
by
it
as
before
the
Air
began
to
be
pump'd
out
.
I
said
very
near
,
rather
than
altogether
,
because
that
the
withdrawing
of
the
Air
,
though
it
be
not
suppos'd
to
weaken
at
all
the
Power
of
the
Loadstone
precisely
considered
,
yet
it
must
lessen
its
power
to
sustain
the
Steel
,
because
this
in
so
thin
a
medium
must
weigh
heavier
,
than
in
the
Air
,
by
the
weight
of
as
much
Air
,
as
is
equal
in
bulk
to
the
appended
Body
.
Some
other
Magnetical
Tryals
(
and
also
some
Electrical
ones
)
I
remember
I
attempted
to
make
by
the
help
of
our
Engine
,
but
not
having
the
Notes
I
took
of
them
now
at
hand
,
I
shall
suspend
the
mentioning
them
,
till
I
can
give
Your
Lordship
a
more
punctual
Account
of
them
.
EXPERIMENT
XXXII
.
Shewing
,
that
when
the
Pressure
of
the
External
Air
is
taken
off
,
t
is
very
easie
to
draw
up
the
Sucker
of
a
Syringe
,
though
the
Hole
,
at
which
the
Air
or
Water
should
succeed
,
be
stopp'd
.
HAving
taken
notice
,
that
some
learned
Opposers
of
the
Modern
Doctrine
about
the
weight
of
the
Atmosphere
think
themselves
more
than
ordinarily
befriended
by
the
difficulty
we
find
in
drawing
up
the
Embolus
or
Sucker
of
a
Syringe
,
when
the
hole
,
at
which
the
Air
or
Water
should
succeed
,
is
stopt
,
and
by
the
violence
,
with
which
,
as
soon
as
t
is
let
go
,
tis
,
as
they
imagine
,
drawn
back
.
And
supposing
the
reason
of
this
confidence
of
theirs
to
be
,
that
Men
have
not
yet
been
able
in
these
Phaenomena
(
as
in
some
others
)
to
prove
the
interest
of
the
Atmosphere's
Gravity
by
direct
or
confessedly
analogous
Experiments
;
I
presum'd
it
will
not
be
unwelcome
to
Your
Lordship
,
if
I
here
fortifie
the
Speculations
that
have
been
or
may
be
propos'd
to
explicate
these
things
according
to
the
Hypothesis
of
the
weight
of
the
Air
,
by
what
we
tried
to
that
purpose
,
among
others
,
when
we
were
making
use
of
a
Syringe
in
our
Engine
.
The
I.
Tryal
.
We
took
a
Syringe
of
Brass
,
(
that
Metal
being
closer
and
stronger
then
Pewter
,
of
which
such
instruments
are
usually
made
,
)
being
in
length
(
in
the
Barrel
)
about
6
inches
,
and
in
Diameter
about
1
inch
⅜
and
having
,
by
putting
a
thin
Bladder
about
the
Sucker
,
and
by
pouring
a
litle
Oyl
into
the
cavity
of
the
Cylinder
(
or
Barrel
,
)
brought
the
instrument
to
be
stanch
enough
,
and
yet
the
Sucker
to
move
to
and
fro
without
much
difficulty
,
we
thrust
this
to
the
bottom
(
or
Basis
)
of
the
Barrel
to
exclude
the
Air
,
and
having
unscrew'd
and
laid
aside
the
slender
Pipe
of
the
Syringe
(
which
in
this
and
some
other
Tryals
was
like
to
prove
not
onely
needless
,
but
inconvenient
)
we
carefully
stopt
the
Orifice
,
to
which
the
Pipe
in
these
instruments
is
wont
to
be
screw'd
,
and
then
drawing
up
the
Sucker
we
let
it
go
,
to
judg
by
the
violence
,
with
which
it
would
be
driven
back
again
,
whether
the
Syringe
were
light
enough
for
our
purpose
,
and
finding
it
to
be
so
,
we
fastned
to
the
Barrel
a
ponderous
piece
of
Iron
to
keep
it
down
,
and
then
fastning
to
the
handle
of
the
Rammer
(
or
Axle-tree
of
the
Sucker
)
one
end
of
a
String
,
whose
other
end
was
tied
to
the
often
mentioned
turning-key
:
We
convey'd
this
Syringe
,
and
the
weight
belonging
unto
it
,
into
a
Receiver
;
and
having
pump'd
out
the
Air
,
we
then
began
to
turn
the
Key
,
thereby
to
shorten
the
String
that
tied
the
handle
of
the
Syringe
to
it
;
and
,
as
we
foretold
,
that
the
Pressure
of
the
Air
,
lately
included
in
the
Receiver
,
being
withdrawn
,
we
should
no
more
find
the
wonted
resistance
in
drawing
up
the
Sucker
from
the
bottom
of
the
Cylinder
,
so
we
found
upon
Tryal
that
we
could
very
easily
pull
it
up
without
finding
any
sensible
resistance
.
However
having
thought
fit
to
repeat
the
Experiment
,
(
which
we
did
with
the
like
success
,
)
lest
it
might
might
be
objected
,
that
this
want
of
resistance
might
proceed
,
as
partly
from
our
imploying
the
Turning-key
to
raise
the
Sucker
,
so
principally
from
some
unperceived
Leak
,
at
which
the
Air
may
be
suppos'd
to
have
got
into
the
cavity
of
the
Cylinder
;
I
thought
fit
not
onely
to
examine
by
Tryal
,
after
the
Receiver
was
remov'd
from
off
the
Pump
,
whether
the
Syringe
were
not
stanch
,
(
upon
which
I
found
that
I
could
not
,
without
some
straining
,
draw
up
the
Sucker
even
a
litle
way
,
and
that
it
would
be
violently
beaten
back
again
,
)
but
also
in
one
of
these
Experiments
to
make
this
variation
;
That
when
,
the
Receiver
being
exhausted
,
we
had
drawn
up
the
Sucker
almost
to
the
top
of
the
Barrel
by
such
a
string
as
was
purposely
chosen
somewhat
weak
,
we
kept
the
parts
of
the
Syring
in
that
posture
,
till
we
had
open'd
a
passage
to
the
outward
Air
,
upon
whose
ingress
the
Sucker
was
(
as
we
intended
it
should
be
)
so
forceably
deprest
,
that
it
broke
the
String
by
which
it
was
tied
to
the
Turning-key
,
and
was
violently
driven
back
to
the
lower
part
of
the
Barrel
,
&
that
notwithstanding
these
two
disadvantageous
Circumstances
;
one
,
that
the
string
was
not
so
weak
,
but
that
one
,
whom
I
imploy'd
to
try
it
before
it
was
fastned
to
the
Syringe
,
made
it
sustain
a
lump
of
Iron
that
weighed
between
four
and
five
pound
;
and
the
other
,
that
yet
this
string
was
broken
long
before
all
the
Air
,
that
flowed
in
to
fill
the
Receiver
,
had
got
in
:
so
that
the
pressure
of
all
the
admitted
Air
would
doubtless
have
broken
a
much
stronger
string
,
if
we
had
imploy'd
such
a
one
to
resist
the
depression
of
the
Sucker
,
which
will
yet
be
more
evident
by
a
phaenomenon
of
our
Syringe
,
that
I
shall
presently
have
occasion
to
relate
.
The
II.
TRYAL
.
Containing
a
Variation
of
the
foregoing
.
We
took
the
Syringe
imploy'd
in
the
foregoing
Experiments
,
and
having
found
by
Tryal
that
it
was
,
though
not
perfectly
,
tite
,
(
nor
altogether
so
much
so
as
before
,
)
yet
enough
so
for
our
present
purpose
,
(
since
,
when
the
Orifice
of
the
vent
in
the
Basis
was
stopt
,
if
the
Sucker
were
more
forceably
drawn
up
a
litle
way
,
and
then
let
go
,
it
would
hastily
return
,
or
rather
violently
be
impell'd
back
towards
the
bottom
of
the
Barrel
,
)
we
made
it
serve
us
as
well
as
we
could
for
the
following
Experiment
.
Of
this
Syringe
we
did
very
carefully
with
a
Cork
and
our
Cement
close
the
vent
;
and
then
having
tied
to
the
barrel
of
the
Syring
a
Weight
that
hapned
to
be
at
hand
,
(
and
to
amount
to
2
Pound
,
and
as
many
Ounces
,
)
we
suspended
the
Rammer
of
the
Syringe
by
a
string
in
a
large
Receiver
;
and
then
causing
the
Pump
to
be
applied
,
we
made
11
or
12
Exuctions
of
the
Air
,
without
any
appearance
of
change
in
the
Syringe
:
but
because
I
had
judg'd
the
above
mentioned
Weight
sufficient
,
and
suppos'd
that
the
little
Air
still
remaining
in
the
Receiver
,
had
yet
too
strong
a
Pressure
to
be
surmounted
by
it
,
I
caus'd
the
Pumping
to
be
continued
,
and
within
2
or
three
Exuctions
more
I
perceiv'd
the
Cylinder
to
begin
to
be
drawn
down
(
though
but
very
slowly
)
by
the
Weight
hanging
at
it
,
(
assisted
by
its
own
Gravity
:
)
and
likewise
tried
(
after
having
purposely
stopt
a
while
the
working
of
the
Pump
)
that
just
upon
a
fresh
Suck
the
descent
would
be
manifestly
accelerated
.
And
when
we
had
suffer'd
the
Barrel
and
Weight
to
slide
down
as
far
as
we
thought
fit
,
we
let
in
the
External
Air
,
which
(
as
was
to
be
expected
)
rais'd
them
both
again
much
faster
than
they
had
subsided
.
NB.
There
would
not
have
needed
any
thing
near
so
great
a
Weight
to
depress
the
Barrel
of
the
Syringe
,
but
that
it
is
difficult
in
such
an
instrument
to
make
the
Sucker
fill
it
accurately
enough
,
without
making
it
somewhat
uneasie
to
be
mov'd
to
and
fro
:
Upon
which
account
t
was
necessary
that
a
Weight
should
be
added
,
not
onely
to
surmount
the
Pressure
of
the
Air
remaining
in
the
Receiver
,
(
which
was
not
,
nor
needed
to
be
diligently
exhausted
in
this
Experiment
,
)
but
to
overcome
that
resistance
,
which
we
just
now
noted
the
inequalities
of
the
inside
of
the
Cylinder
and
those
of
the
Sucker
to
give
to
the
motion
of
the
one
in
or
over
the
other
.
And
yet
for
all
this
t
is
not
easie
,
though
it
be
not
impossible
,
to
make
one
of
these
Syringes
very
Tight
,
especially
when
the
Nose
is
well
stopt
,
and
the
Sucker
drawn
up
;
there
being
often
some
litle
Air
that
strains
in
between
the
Sucker
and
the
Barrel
,
and
some
that
will
be
harbour'd
between
the
Sucker
(
though
thrust
home
)
and
the
bottom
of
the
Barrel
,
besides
what
may
lurk
between
the
same
Sucker
and
the
Cork
that
stops
the
orifice
of
the
Vent
.
Nor
were
we
confident
,
that
our
Syringe
did
not
at
length
let
some
Aerial
particles
insinuate
themselves
into
the
Cavity
,
which
the
depression
of
the
Barrel
had
made
betwixt
the
Bases
of
that
Barrel
and
the
Sucker
:
and
in
such
cases
we
ought
not
to
wonder
,
if
upon
the
return
of
the
Air
the
Barrel
and
Weight
be
not
impell'd
up
all
together
to
the
same
height
they
rested
at
,
when
they
were
first
suspended
in
the
Receiver
.
2.
It
agreed
very
well
with
our
Doctrine
,
that
as
the
Cylinder
and
Weight
began
not
to
fall
,
till
a
great
quantity
of
Air
had
been
pump'd
out
of
the
Receiver
,
so
they
did
not
begin
to
move
upwards
presently
upon
the
freedom
that
was
allow'd
the
Air
to
return
into
the
Receiver
.
For
till
it
had
continued
a
pretty
while
flowing
in
,
there
was
not
enough
of
it
entred
to
restore
by
its
pressure
the
Cylinder
and
the
annexed
Weight
to
their
former
situation
.
3.
What
has
been
deliver'd
about
our
Experiment
may
be
confirm'd
by
this
Variation
which
we
made
of
it
:
That
having
substituted
a
far
heavier
Weight
instead
of
that
lately
mention'd
,
the
depression
of
the
Barrel
of
the
Syringe
succeeded
2
or
3
times
one
after
another
much
sooner
than
formerly
,
viz.
about
the
sixth
,
or
at
most
,
the
seaventh
Exuction
.
EXPERIMENT
XXXIII
.
About
the
opening
of
a
Syringe
,
whose
Pipe
was
stopt
in
the
Exhausted
Receiver
,
and
by
the
help
of
it
making
the
Pressure
of
the
Air
lift
up
a
considerable
Weight
.
THough
the
Trial
I
am
about
to
relate
,
had
not
all
the
success
I
desir'd
,
yet
perhaps
it
will
not
be
impertinent
to
make
mention
of
it
,
because
there
is
not
any
sort
of
Experiments
,
that
is
wont
so
much
to
perswade
the
Generality
of
Spectators
,
of
the
great
force
of
the
Pressure
of
the
Air
,
as
those
,
wherein
they
plainly
see
heavy
and
solid
Bodies
made
to
ascend
,
(
upon
the
operation
of
the
Air
on
them
,
)
without
seeing
any
other
thing
lift
them
up
.
We
took
the
often
mention'd
Syringe
,
and
having
clos'd
up
the
Hole
at
the
bottom
with
good
Cement
,
we
ty'd
to
the
Barrel
a
hollow
piece
of
Iron
,
that
serv'd
us
for
a
Scale
,
into
which
we
put
divers
Weights
one
after
another
,
trying
from
time
to
time
whether
,
when
the
Sucker
was
forceably
drawn
up
,
and
held
steddily
in
its
highest
station
,
the
Weight
tyed
to
the
Barrel
(
which
was
held
down
,
whilst
the
Sucker
was
drawn
up
,
and
afterwards
let
go
)
would
be
considerably
rais'd
.
And
when
we
perceiv'd
,
that
the
addition
of
half
a
Pound
,
or
a
Pound
more
,
would
make
the
Weight
too
Great
to
be
so
rais'd
,
we
forbore
to
put
in
that
increase
of
weight
;
and
having
tied
the
Handle
of
the
Rammer
to
the
Turning-key
,
we
convey'd
the
Syringe
together
with
its
clog
into
a
Receiver
,
out
of
which
a
convenient
quantity
of
Air
being
pump'd
,
we
were
thereby
enabled
easily
to
draw
up
the
Sucker
without
the
Cylinder
;
after
which
having
let
in
the
Air
,
the
by-standers
concluded
,
that
the
weight
was
rais'd
a
litle
,
which
yet
I
would
not
have
allow'd
,
if
we
had
not
been
able
,
by
inclining
the
Engine
and
the
Receiver
,
to
make
the
Syringe
and
Weight
a
litle
to
swing
.
But
to
make
the
effect
more
evident
,
I
caus'd
a
two
pound
weight
to
be
taken
out
,
and
then
the
Receiver
being
somewhat
exhausted
,
and
the
Air
readmitted
,
the
Clog
,
when
all
the
Air
was
come
in
,
was
swiftly
raised
,
and
as
it
were
snatch'd
up
from
the
midle
to
the
upper
part
of
the
suspended
Rammer
.
It
is
no
easie
matter
to
measure
,
with
any
certainty
and
exactness
by
a
Syringe
,
the
weight
of
an
Atmospherical
Pillar
equal
to
it
in
Diameter
,
especially
if
there
be
any
imperfection
in
the
Syringe
,
either
because
the
Sucker
does
not
go
close
enough
,
in
which
case
it
can
scarce
be
stanch
,
or
because
by
its
Pressure
against
the
inside
of
the
Barrel
(
which
often
happens
if
it
be
too
close
)
it
hinders
the
Sucker
and
Barrel
from
sliding
without
resistance
by
one
another
,
and
consequently
there
is
an
undue
resistance
made
to
the
endeavour
of
the
Atmosphere
,
to
raise
the
Barrel
and
Weight
.
And
therefore
,
though
our
Syringe
being
,
upon
the
account
of
some
ill
accident
,
less
in
order
than
it
was
in
some
of
the
foregoing
Experiments
,
I
must
not
conclude
that
a
Cylinder
of
the
Atmosphere
of
the
same
wideness
with
it
,
is
equipollent
to
no
greater
a
weight
,
than
that
which
was
taken
up
in
our
Trial
,
yet
we
may
safely
conclude
that
so
slender
a
Pillar
of
the
Atmosphere
is
able
to
raise
by
a
Syringe
at
least
such
a
Weight
,
as
in
our
Experiment
it
actually
lifted
up
,
which
amounted
to
about
sixteen
pound
(
Haberdupoise
weight
,
)
for
it
exceeded
fifteen
pound
and
three
quarters
,
besides
the
weight
of
the
Syringes
barrel
it self
.
EXPERIMENT
XXXIV
.
Shewing
,
that
the
cause
of
the
Ascension
of
Liquors
in
Syringes
is
to
be
deriv'd
from
the
Pressure
of
the
Air.
I
Shall
not
here
trouble
Your
Lordship
with
what
I
have
elsewhere
propos'd
about
the
explicating
of
Suction
:
but
as
by
the
lately
recited
Experiments
(
I
mean
the
31
,
32
,
and
33
)
it
has
appear'd
,
that
t
is
to
the
Pressure
of
the
External
Air
that
we
should
ascribe
the
difficulty
of
drawing
up
the
Sucker
of
a
Syring
,
when
the
Pipe
(
or
the
Vent
)
is
stopt
;
so
I
shall
now
endeavour
to
shew
,
that
the
Ascension
of
Liquors
,
which
follow
the
Sucker
when
t
is
drawn
up
,
the
Pipe
being
open
,
depends
also
upon
the
Pressure
of
the
Air
,
(
incumbent
on
that
Liquor
.
)
If
I
had
been
furnish'd
with
very
tall
Receivers
,
and
such
other
Glasses
as
I
could
have
wish'd
,
I
had
tried
the
following
Experiments
with
Water
,
as
well
as
Quick-silver
,
but
for
want
of
those
Accommodations
I
was
reduc'd
to
make
my
Experiment
with
the
later
onely
of
those
Liquors
,
which
yet
will
I
hope
sufficiently
make
out
what
was
intended
.
The
I.
Tryal
.
We
took
a
small
Receiver
,
shap'd
almost
like
a
Pear
,
cut
off
Horizontally
at
both
ends
,
(
being
the
same
cap'd
Glass
that
is
elsewhere
mentioned
in
the
accounts
of
other
Experiments
:
)
That
which
now
remained
,
being
to
try
the
Experiment
it self
,
in
order
to
which
all
this
had
been
done
,
the
Air
was
pump'd
out
of
the
Receiver
,
(
and
consequently
out
of
the
little
Glass
that
held
the
Mercury
,
)
and
then
the
Sucker
being
warily
drawn
up
,
we
could
not
see
the
Quick-silver
ascend
to
follow
it
,
though
a
litle
Water
,
which
it
seems
the
outward
Air
had
thrust
in
between
the
Sucker
and
the
Cylinder
,
was
either
rais'd
or
stopt
in
the
Glass-pipe
of
the
Syringe
,
(
whereof
yet
much
the
greatest
part
remain'd
unfill'd
;
)
of
which
the
reason
according
to
our
Hypothesis
was
manifest
,
namely
,
that
the
Air
being
pump'd
out
of
the
Receiver
,
the
litle
that
remain'd
had
not
strength
enough
to
press
up
so
ponderous
a
Liquor
as
the
Quick-silver
into
the
Pipe
,
(
though
even
that
litle
unexhausted
Air
might
have
Spring
enough
left
to
raise
a
litle
water
.
)
And
since
it
appear'd
by
this
,
that
without
the
Pressure
of
the
Air
the
Quick-silver
would
not
be
elevated
,
we
thought
it
seasonable
to
shew
,
that
by
the
Pressure
of
the
Air
it
would
.
Whereupon
the
Air
being
let
slowly
into
the
Receiver
,
the
Mercury
was
quickly
impell'd
up
at
least
to
the
top
of
the
Glass-pipe
,
(
though
by
reason
of
some
unperceiv'd
leak
it
was
not
long
sustain'd
there
.
)
And
for
further
satisfaction
,
when
the
Experiment
was
to
be
tried
over
again
,
we
order'd
it
to
be
so
made
,
that
it
might
plainly
be
observed
,
that
though
when
,
the
Receiver
not
being
yet
exhausted
,
the
Sucker
was
drawn
up
but
one
inch
,
the
Mercury
would
be
rais'd
to
the
upper
part
of
the
Glass-pipe
of
the
Syringe
,
yet
after
the
exhausting
of
the
Receiver
,
though
the
Sucker
was
drawn
up
twice
as
high
,
there
appear'd
no
ascension
of
the
Mercury
in
the
Pipe
,
(
whose
lower
part
onely
was
darkned
by
the
litle
Glass
which
contain'd
that
fluid
Metal
.
)
Before
I
dismiss
this
Experiment
,
I
must
,
to
make
good
a
promise
I
made
Your
Lordship
,
acquaint
You
with
a
Phaenomenon
,
which
does
not
a
litle
confirm
our
Doctrine
,
according
to
which
it
was
easie
both
to
foresee
and
to
explain
it
:
The
phaenomenon
was
,
That
if
when
the
Air
was
diligently
pump'd
out
of
the
Receiver
,
the
Sucker
were
endeavour'd
to
be
pull'd
up
,
it
could
not
be
so
,
without
much
difficulty
and
resistance
,
such
as
was
formerly
found
when
the
Vent
of
the
Syringe
was
stopt
,
of
which
in
our
Hypothesis
the
reason
may
be
clearly
this
;
That
there
being
no
common
Air
in
the
Receiver
to
assist
by
its
Pressure
(
whether
immediate
or
mediate
)
the
raising
of
the
Sucker
,
this
could
not
be
raised
but
by
a
force
great
enough
to
surmount
the
Weight
of
the
external
Air
or
Atmospherical
Pillar
that
lean'd
upon
it
.
So
that
as
the
other
Phaenomena
of
our
Experiments
manifest
,
that
the
raising
of
Liquors
by
a
Syringe
,
which
is
commonly
ascrib'd
to
Attraction
,
depends
upon
the
Pressure
of
the
Air
;
so
by
this
Phaenomenon
it
appears
,
that
the
difficulty
of
opening
a
Syringe
,
whose
Pipe
is
stopt
,
need
not
be
attributed
to
such
a
fuga
vacui
as
vulgar
Philosophers
refer
it
to
;
since
in
our
case
the
same
difficulty
was
found
,
though
the
Pipe
were
open
,
and
the
Liquor
't
was
immerst
in
,
might
have
had
free
access
to
the
place
deserted
by
the
Sucker
.
The
II.
Tryal
Being
a
Prosecution
of
the
former
Attempt
.
To
vary
as
well
as
confirm
the
foregoing
Experiment
,
we
caus'd
the
Syringe
to
be
tied
fast
to
a
competently
ponderous
Body
that
might
keep
the
Cylinder
unmov'd
,
when
the
Sucker
should
be
drawn
up
.
We
also
cemented
on
to
the
vent
or
screw
at
the
bottom
of
the
Syringe
a
Pipe
of
glass
of
about
two
inches
in
length
,
(
which
should
have
been
longer
,
but
that
then
there
would
not
have
been
room
in
the
Receiver
for
the
pulling
up
of
the
Sucker
,
)
and
having
plac'd
the
heavy
Body
whereto
the
Syringe
was
tied
upon
a
Pedestal
of
a
convenient
height
,
that
the
Glass-pipe
might
be
all
seen
beneath
it
,
and
a
very
low
Viol
almost
fill'd
with
Quick-silver
might
be
so
plac'd
underneath
the
Pipe
,
that
the
stagnant
Mercury
reach'd
a
good
way
above
the
immerst
orifice
of
the
said
Pipe
.
These
things
being
thus
provided
,
and
the
Handle
of
the
Syringes
Rammer
being
tied
with
a
string
to
the
Turning-key
that
belong'd
to
the
Brass-cover
of
the
Receiver
,
this
vessel
was
cemented
on
to
the
Engine
,
and
by
it
Exhausted
after
the
usual
manner
.
When
this
was
done
,
we
look'd
upon
the
Syringes
Glass-pipe
above
mentioned
,
and
being
able
to
see
through
it
,
(
whereby
we
were
certain
that
it
was
not
yet
full
of
Quick-silver
)
we
did
by
the
string
draw
up
the
Sucker
to
a
good
height
,
but
could
not
perceive
the
Pipe
to
be
fill'd
with
any
succeeding
Mercury
.
Wherefore
warily
letting
in
some
Air
,
we
quickly
saw
the
Mercury
impell'd
to
the
very
top
of
the
Pipe
;
and
we
concluded
from
the
quantity
of
Quick-silver
that
was
rais'd
,
that
a
pretty
deal
was
also
driven
into
the
cavity
of
the
Cylinder
.
NB.
I
had
once
before
seen
the
Mercury
ascend
into
the
Pipe
upon
the
letting
in
of
the
Air
into
the
emptied
Receiver
,
but
it
seeming
somewhat
difficult
to
me
to
determine
whether
the
Sucker
had
been
raised
,
because
there
was
no
mark
to
guide
my
Aestimate
by
,
I
thought
it
might
be
suspected
,
that
in
case
the
Sucker
had
not
been
rais'd
,
the
Ascension
of
the
Quick-silver
might
have
proceeded
from
hence
,
That
the
Air
contain'd
in
the
Glass-pipe
,
breaking
out
through
the
stagnant
Mercury
upon
the
Exhausting
of
the
Receiver
,
the
Quick-silver
might
upon
the
return
of
the
Air
into
the
Receiver
be
prest
up
into
the
place
deserted
by
the
Air
,
that
broke
out
of
the
Pipe
.
Wherefore
we
caus'd
a
string
to
be
tied
about
the
Rammer
,
as
near
as
we
could
to
the
top
of
the
Cylinder
,
by
which
means
,
when
the
Receiver
was
the
next
time
exhausted
,
we
perceiv'd
,
that
by
drawing
up
the
Sucker
vve
had
rais'd
it
about
two
inches
,
if
not
more
,
and
yet
vve
could
not
discern
any
Mercury
to
follow
it
,
(
the
Glass-pipe
still
continuing
transparent
,
)
till
we
had
let
some
Air
return
into
the
Receiver
.
This
Experiment
joyn'd
with
those
we
have
formerly
related
to
have
been
tried
with
our
Syringe
,
may
teach
us
,
that
if
a
Syringe
were
made
use
of
above
the
Atmosphere
,
neither
the
stopping
of
the
Pipe
vvould
hinder
the
easy
drawing
up
of
the
Sucker
,
nor
the
drawing
up
of
the
Sucker
,
though
the
Pipe
vvere
not
stopt
,
vvould
raise
by
suction
the
Liquor
vvhich
the
Pipe
was
immerst
in
.
Postscript
.
SInce
the
last
recited
Experiment
was
made
,
and
written
,
finding
some
of
our
Instruments
to
be
in
better
order
than
they
were
when
that
Tryal
was
made
,
vve
thought
fit
to
endeavour
by
that
which
follows
,
to
repair
an
omission
or
two
,
that
formerly
we
could
not
well
avoid
.
Having
then
caus'd
such
a
Glass-pipe
,
as
has
been
lately
mentioned
,
to
be
vvell
cemented
on
to
the
Syringe
,
(
vvhose
Sucker
did
now
move
more
easily
,
and
yet
fill
the
Barrel
more
exactly
,
than
before
,
)
I
order'd
(
being
to
be
absent
for
a
while
my self
)
that
the
Pipe
should
be
fill'd
with
spirit
of
Wine
tincted
with
Cocheneel
,
that
the
liquor
and
its
motions
might
be
the
better
discern'd
,
and
that
the
Pipe
being
fill'd
,
that
Air
might
be
excluded
,
which
vvould
else
be
harboured
in
the
Pipe
,
(
which
Caution
was
omitted
in
the
foregoing
Experiment
.
)
And
this
the
Person
,
to
whom
I
committed
it
,
affirm'd
to
have
been
carefully
done
,
though
when
he
inverted
the
Pipe
thus
fill'd
into
the
rest
of
the
red
Liquor
,
that
was
put
into
a
Viol
,
he
could
not
possibly
do
it
so
well
,
but
that
a
bubble
of
Air
got
into
the
Pipe
,
and
took
up
some
(
though
but
a
litle
)
room
there
.
By
that
time
,
I
was
call'd
upon
,
to
see
the
Event
of
the
Tryal
,
and
could
come
to
look
upon
it
,
the
Receiver
was
almost
quite
exhausted
;
vvherefore
after
I
had
made
the
pumping
be
continued
a
litle
longer
,
and
perceived
that
the
tincted
spirit
was
fallen
down
out
of
the
Pipe
,
and
that
which
lay
in
the
Viol
seem'd
almost
to
boyl
at
the
top
,
by
reason
of
the
emersion
of
numerous
Bubbles
,
I
caus'd
the
Sucker
to
be
,
by
the
help
of
the
Turning-key
,
drawn
up
(
by
our
aestimate
)
about
two
inches
and
a
half
,
notwithstanding
which
vve
could
not
perceive
the
spirit
of
Wine
to
rise
in
the
Pipe
,
(
though
the
Pumping
were
before
left
off
.
)
For
vvhich
reason
I
order'd
the
Air
to
be
let
in
very
leisurely
,
upon
which
vve
could
plainly
see
that
the
red
spirit
was
quickly
driven
up
to
the
top
of
the
Pipe
,
and
that
it
was
so
likewise
into
the
Cavity
of
the
Barrel
,
appeared
,
when
the
Receiver
was
removed
,
by
the
small
Quantity
of
Liquor
that
remained
in
the
viol
,
and
the
plenty
of
it
which
came
out
of
the
Syringe
.
NB.
That
if
I
had
not
vvanted
dexterous
Artificers
,
to
work
according
to
a
Contrivance
I
had
design'd
,
I
had
attempted
to
imitate
,
by
the
help
of
the
bare
Spring
of
the
Air
,
such
Experiments
,
as
in
the
lately
recited
Tryals
vvere
made
to
succeed
,
by
the
help
of
the
Pressure
exercis'd
by
the
Air
upon
the
account
of
its
Weight
.
EXPERIMENT
XXXV
.
Shewing
,
that
upon
the
Pressure
of
the
Air
depends
the
sticking
of
Cupping
Glasses
to
the
fleshy
parts
they
are
apply'd
to
.
T
Is
sufficiently
known
,
that
if
the
Air
within
a
Cupping
Glass
be
rarified
by
the
flame
of
Tow
,
Flax
,
or
the
like
,
(
burn'd
for
a
litle
while
in
it
,
)
and
the
Glass
be
presently
clapt
upon
some
fleshy
part
of
a
Mans
body
,
there
will
quickly
ensue
a
painful
and
visible
swelling
of
the
part
cover'd
by
the
Cupping
Glass
.
T
is
also
known
,
that
this
Experiment
is
wont
to
be
urg'd
by
the
Schools
as
a
clear
proof
of
that
abhorrence
of
a
Vacuum
they
ascribe
to
Nature
;
for
,
say
they
,
the
reason
of
this
phaenomenon
is
plainly
,
that
the
internal
Air
of
the
Cupping
Glass
,
praeternaturally
rarified
by
heat
when
the
Instrument
is
applied
,
That
heat
after
a
while
ceasing
,
the
succeeding
Cold
must
again
necessarily
condense
the
Air
;
and
so
this
contracted
Air
being
no
longer
able
to
fill
the
whole
space
it
replenished
before
,
there
would
ensue
a
vacuum
,
if
the
flesh
covered
by
the
Cupping
Glass
,
or
adjoyning
to
it
,
did
not
swell
into
the
Cavity
of
it
,
to
fill
the
place
deserted
by
the
Air.
Those
Moderns
that
assert
the
Weight
of
the
Atmosphere
,
do
thence
ingeniously
endeavour
to
deduce
the
phaenomenon
.
And
indeed
if
to
their
Hypothesis
about
the
Airs
Weight
,
the
consideration
of
its
Spring
be
added
,
't
will
be
easie
enough
to
explicate
the
phaenomenon
,
by
saying
,
That
when
the
Cupping
Glass
is
first
set
on
,
though
much
of
the
Air
it
formerly
contain'd
were
a
litle
before
expell'd
by
the
heat
,
yet
the
same
heat
,
increasing
the
pressure
of
the
remaining
Air
,
is
the
cause
that
the
absence
of
the
Air
driven
out
of
the
Glass
,
does
not
immediately
occasion
so
sensible
a
pain
:
but
,
when
that
adventitious
agitation
of
the
included
Air
ceases
,
that
Air
having
now
,
because
of
the
paucity
of
its
Corpuscles
,
but
a
weak
Spring
,
can
no
longer
press
upon
the
part
covered
by
the
Cupping
Glass
neer
so
strongly
,
as
the
outward
Air
does
by
its
Weight
press
upon
all
the
neighbouring
parts
of
the
flesh
:
by
which
means
(
according
to
what
we
have
more
than
once
explicated
already
)
some
of
the
yielding
flesh
(
or
other
body
covered
by
the
skin
)
must
be
forceably
thrust
into
the
cavity
of
the
Cupping
Glass
,
where
there
is
less
Pressure
,
then
at
the
outside
of
it
.
And
the
fibres
and
membranous
parts
being
thus
violently
stretcht
,
there
must
needs
follow
a
sensible
Pain
as
well
as
Tumour
.
Which
Tumour
yet
does
not
fill
up
the
Cupping
Glass
,
not
onely
because
of
the
resistance
of
the
skin
to
be
so
far
distended
,
but
also
,
if
the
included
Air
have
not
been
much
rarified
because
of
the
Spring
of
the
imprisoned
Air
,
(
which
grows
so
much
the
stronger
,
by
how
much
the
swelling
flesh
reduces
the
Air
into
less
room
,
)
as
I
have
sometimes
tried
,
by
applying
a
Cupping
Glass
to
Quick-silver
,
or
even
to
Water
,
which
will
rise
in
it
but
to
a
certain
height
.
But
though
by
this
,
or
some
such
Explication
,
the
Argument
urged
by
the
Schools
in
favour
of
the
fuga
vacui
may
be
sufficiently
enervated
;
yet
it
suited
better
with
the
design
of
this
Treatise
to
propose
some
new
Experiment
,
to
illustrate
our
Hypothesis
;
and
though
it
seem'd
to
be
far
more
difficult
to
do
it
in
reference
to
Cupping
Glasses
,
than
to
other
subjects
,
yet
I
pitcht
upon
two
different
wayes
of
Experimenting
;
whose
success
not
disappointing
me
,
I
shall
now
give
Your
Lordship
an
account
of
them
,
We
took
a
Glass
of
about
one
Inch
and
a
half
in
Diameter
,
but
a
good
deal
longer
,
than
an
ordinarily
shap'd
Cupping
Glass
of
that
breadth
would
have
been
,
that
there
might
be
the
more
room
for
the
flame
to
burn
in
it
,
and
rarifie
the
Air.
We
also
provided
a
Receiver
shap'd
almost
like
a
Pear
,
this
Receiver
was
open
at
both
ends
;
at
the
sharper
whereof
there
was
but
a
small
orifice
,
but
at
the
obtuse
end
there
rose
up
a
short
neck
,
whose
Orifice
was
wide
enough
to
admit
with
ease
the
newly
mentioned
Cupping
Glass
without
touching
the
sides
of
it
,
and
we
were
not
willing
it
should
be
much
larger
,
lest
it
should
not
be
so
exactly
cover'd
by
the
Palm
of
the
hand
that
should
be
laid
upon
it
,
and
lest
also
the
hand
should
be
broken
or
hurt
by
the
too
great
weight
of
the
Atmosphere
,
when
the
included
Air
should
be
withdrawn
from
under
it
.
These
things
being
thus
prepared
,
and
the
smaller
Orifice
of
the
Receiver
being
fastned
with
Cement
to
the
Engine
,
I
caused
the
Cupping
Glass
to
be
fastned
,
with
the
mouth
upwards
,
to
the
Palm
of
the
hand
of
a
Youth
,
(
whom
your
Lordship
may
remember
to
have
seen
with
me
,
)
whose
hand
seem'd
fram'd
by
Nature
for
this
Experiment
,
being
broad
,
strong
,
and
very
plump
.
And
having
pull'd
the
Glass
,
to
try
whether
it
stuck
well
on
,
I
caus'd
him
to
put
it
into
the
Receiver
,
and
lay
his
hand
so
upon
the
Orifice
lately
mentioned
,
that
it
might
serve
for
a
Cover
to
it
,
and
hinder
any
Air
from
getting
in
between
them
.
That
which
we
pretended
was
,
that
the
Receiver
being
but
small
,
(
that
it
might
be
quickly
exhausted
,
and
so
not
put
the
Youth
to
a
long
pain
,
)
upon
an
Exuction
or
two
made
with
the
Pump
,
of
the
Air
about
the
Cupping
Glass
,
the
remaining
Air
should
have
its
Pressure
so
far
weakned
,
as
not
to
be
able
to
support
the
Cupping
Glass
;
especially
since
if
the
Air
without
the
Cupping
Glass
(
but
yet
in
the
Receiver
)
should
be
more
rarified
by
the
removal
of
that
which
had
been
pump'd
out
,
than
the
Air
included
in
the
Cupping
Glass
was
by
the
precedent
Heat
;
this
last
mentioned
Air
having
a
stronger
Spring
(
or
tendency
to
expand
it self
)
than
the
External
Air
of
the
Receiver
,
the
Glass
must
needs
fall
down
,
or
rather
be
thrust
off
,
though
,
in
case
there
had
been
no
Air
at
all
left
in
the
Cavity
of
the
Cupping
Glass
,
the
Air
in
the
Receiver
would
by
its
Pressure
sustain
a
far
Greater
weight
.
The
Event
of
our
Trial
agreed
very
well
with
our
conjecture
.
For
upon
the
first
Suck
the
Cupping
Glass
fell
off
,
the
weight
of
the
Atmosphere
pressing
so
hard
upon
the
Young
mans
hand
,
that
,
though
he
be
more
than
ordinary
strong
,
he
complain'd
he
could
very
hardly
take
it
off
the
Glass
it
was
almost
thrust
into
,
and
,
a
while
after
,
that
his
hand
was
very
sore
.
But
this
last
inconvenience
became
not
so
quickly
very
sensible
,
but
that
we
had
time
to
repeat
our
Experiment
,
by
fastning
the
Cupping
Glass
more
strongly
than
before
;
so
that
he
complain'd
that
it
drew
in
his
hand
very
forceably
,
and
though
that
part
be
not
wont
to
be
fleshy
,
yet
the
Tumour
occasioned
by
the
Cupping
Glass
was
manifest
enough
to
the
eye
:
but
as
before
,
so
now
,
at
the
very
first
turning
of
the
Stop-cock
,
(
to
let
out
the
Air
of
the
Receiver
,
)
the
Cupping
Glass
fell
off
.
EXPERIMENT
XXXVI
.
About
the
making
,
without
heat
,
a
Cupping
Glass
to
lift
up
a
great
Weight
.
THe
other
Experiment
I
lately
told
Your
Lordship
we
had
made
,
to
illustrate
our
Doctrine
about
the
cause
of
the
sticking
of
applied
Cupping
Glasses
,
was
tried
after
the
following
manner
.
We
took
the
Brass-hoop
or
Ring
,
mentioned
in
the
5th
and
6th
Experiments
,
and
cover'd
it
with
a
Bladder
,
(
which
was
wetted
to
make
it
the
more
limber
,
)
and
was
so
tied
on
to
it
,
(
which
was
easie
to
do
,
)
that
the
bottom
of
the
Bladder
covered
the
upper
orifice
of
the
Hoop
,
and
was
stretcht
(
though
not
strongly
)
upon
it
,
almost
like
the
Membrane
that
makes
the
head
of
a
Drumm
;
and
the
neck
of
the
Bladder
was
tied
with
a
string
near
the
middle
of
the
lower
Orifice
of
the
Hoop
,
and
in
this
lower
part
of
the
Bladder
we
made
two
or
three
small
Holes
for
the
Air
to
pass
in
and
out
at
.
Then
having
plac'd
at
the
bottom
of
the
often
mentioned
capp'd
Receiver
a
thick
piece
of
Wood
,
that
had
a
hole
in
it
,
to
receive
the
neck
of
the
Bladder
,
we
so
plac'd
the
cover'd
Hoop
upon
this
piece
of
Wood
,
that
the
upper
part
of
the
Bladder
lay
parallel
to
the
Horizon
.
This
done
,
we
suspended
,
at
the
Turning-key
belonging
to
the
Cap
of
our
Receiver
,
a
blind
head
(
as
Chymists
call
it
)
of
Glass
,
which
for
want
of
a
true
Cupping
Glass
we
were
fain
to
substitute
,
and
which
indeed
was
not
very
unlike
one
either
for
shape
or
size
;
and
to
the
upper
part
of
this
Glass
we
fastned
a
large
Ring
of
Metal
,
the
better
to
depress
it
,
and
make
it
lean
strongly
on
the
Bladder
.
These
things
being
thus
made
ready
,
and
the
Receiver
cemented
on
to
the
Engine
,
we
did
by
help
of
the
Turning-key
let
down
the
Cupping
Glass
,
(
for
so
we
shall
hereafter
call
it
,
)
till
it
came
almost
to
touch
the
level
Superficies
of
the
Bladder
;
and
when
the
Receiver
was
as
far
exhausted
as
we
thought
fit
,
(
but
not
near
as
far
as
it
might
have
been
,
)
we
let
down
the
Cupping
Glass
a
litle
lower
,
so
that
it
lean'd
upon
the
Bladder
,
and
touch'd
it
with
all
the
parts
of
its
orifice
:
so
that
the
Cupping
Glass
with
the
subjacent
Bladder
was
become
an
internal
Receiver
(
if
I
may
so
call
it
,
)
whose
Air
was
considerably
expanded
,
and
consequently
weakned
as
to
its
Spring
.
All
this
being
done
,
we
warily
let
the
Air
into
the
Receiver
,
and
thereby
the
Air
,
that
did
surround
the
Cupping
Glass
,
(
which
we
just
now
called
the
Internal
Receiver
,
)
having
now
a
stronger
Pressure
than
the
Air
in
the
Cupping
Glass
could
resist
;
the
Bladder
,
on
which
the
Cupping
Glass
rested
,
was
as
we
look'd
for
,
thrust
up
a
pretty
way
into
the
cavity
of
the
Glass
,
in
which
it
made
a
conspicuous
Tumor
;
and
was
made
to
stick
so
close
to
the
orifice
of
it
,
that
one
would
have
thought
that
the
Bladder
had
been
violently
drawn
in
,
as
the
skin
is
wont
to
be
in
the
ordinary
applications
of
Cupping
Glasses
.
And
because
we
took
notice
,
that
though
this
Glass
were
not
capacious
,
(
for
it
scarce
held
a
Pint
of
Water
,
)
yet
the
orifice
of
it
was
not
very
narrow
,
(
being
in
Diameter
an
inch
and
⅘
,
)
we
thought
fit
in
repeating
the
Experiment
to
adde
something
that
seem'd
odd
enough
,
and
was
fit
to
manifest
that
Cupping
Glasses
may
,
without
heat
,
by
the
bare
Pressure
of
the
external
Air
,
be
more
strongly
fastned
,
than
for
ought
we
know
they
are
by
the
help
of
flame
.
Having
then
reiterated
the
former
Experiment
with
this
onely
variation
,
that
we
exhausted
the
Receiver
further
than
before
,
we
took
out
the
Cupping
Glass
and
the
Bladder
,
which
together
with
the
included
Brass-hoop
was
hanging
at
it
;
and
then
having
tied
the
Glass
to
the
Hook
of
a
good
Statera
,
and
tied
a
large
Scale
to
the
neck
of
the
Bladder
,
we
put
in
by
degrees
Weights
into
the
Scale
,
till
we
had
loaded
it
enough
to
force
off
the
Bladder
from
the
Glass
;
which
hapned
not
till
the
whole
Weight
,
that
tended
to
draw
down
the
Bladder
,
amounted
to
35
Pound
(
if
not
better
,
)
of
sixteen
ounces
in
the
pound
.
Nor
did
we
doubt
,
but
that
the
Pressure
of
the
Atmosphere
would
in
our
Experiment
have
kept
up
a
much
greater
Weight
,
if
we
had
,
before
we
let
in
the
outward
Air
,
diligently
exhausted
the
Receiver
;
which
we
had
purposely
forborn
to
do
,
for
fear
the
too
disproportionate
Pressure
of
the
external
Air
should
break
the
Bladder
:
which
puts
me
in
mind
of
adding
,
upon
the
by
,
That
as
more
Weight
was
put
into
the
Scale
,
the
Bladder
(
stretcht
more
and
more
by
the
Weight
on
one
side
,
and
the
Air
on
the
other
,
)
appear'd
to
swell
higher
in
the
cavity
of
the
Glass
.
EXPERIMENT
XXXVII
.
Shewing
,
that
Bellows
,
whose
Nose
is
very
well
stopt
,
will
open
of
themselves
,
when
the
Pressure
of
the
external
Air
is
taken
off
.
IT
is
wont
by
the
Peripateticks
and
others
to
be
made
a
great
argument
for
the
fuga
vacui
which
they
attribute
to
Nature
,
That
if
the
Nose
of
a
pair
of
Bellows
be
well
stopt
,
one
cannot
open
them
by
raising
the
upper
board
from
the
lower
.
But
of
this
another
reason
may
be
easily
assigned
,
without
determining
whether
there
be
a
vacuum
or
no
,
namely
the
Weight
and
Pressure
of
the
Air
:
for
when
the
Nose
of
a
pair
of
Bellows
,
that
are
Tite
enough
,
is
well
stopt
,
no
Air
being
able
to
insinuate
it self
upon
the
disjoining
of
the
boards
into
the
Cavity
made
by
that
disjunction
,
This
cannot
be
effected
,
but
by
such
a
force
as
is
almost
able
(
I
say
almost
,
because
ordinary
Bellows
cannot
be
so
well
shut
,
but
that
there
will
remain
some
Air
in
them
,
whose
Spring
will
facilitate
the
opening
of
them
)
to
raise
an
Atmosphere
Pillar
,
whose
Basis
shall
be
the
upper
board
,
vvhich
is
commonly
so
large
,
that
a
less
force
may
serve
to
break
common
Bellows
,
then
to
raise
so
great
a
Weight
:
but
if
they
vvere
made
strong
enough
,
and
there
vvere
applied
a
sufficient
force
to
lift
so
Great
a
vveight
as
the
newly
mentioned
Pillar
of
the
Atmosphere
,
the
sides
might
be
disjoyn'd
,
how
close
and
stanch
soever
the
Instrument
vvere
made
.
Thus
far
one
may
argue
upon
the
bare
principle
of
the
weight
of
the
Air
,
but
taking
in
the
Spring
of
it
too
,
I
thought
one
might
proceed
so
much
further
,
that
I
ventur'd
to
foretell
divers
ingenious
men
,
that
if
the
Pressure
of
the
ambient
Air
were
taken
off
,
not
onely
it
would
be
easie
to
open
the
Bellows
in
spite
of
their
being
carefully
stopt
at
the
nose
,
but
that
they
would
fly
open
as
it
were
of
their
own
accord
,
without
the
application
of
any
external
force
at
all
.
And
't
was
partly
to
justifie
this
prediction
,
as
well
as
to
make
a
Trial
,
I
thought
more
considerable
,
that
we
made
the
following
Experiment
.
We
caus'd
(
then
)
to
be
made
a
pair
of
Bellows
,
differing
from
ordinary
ones
in
these
particulars
.
First
,
that
the
Boards
were
circular
,
(
and
so
without
handles
,
)
and
of
about
6
inches
in
Diameter
:
2.
That
there
was
no
Clack
or
Valve
:
3.
That
the
nose
was
but
an
inch
long
,
or
less
,
(
being
to
be
lengthned
if
occasion
required
vvith
a
Pipe
:
)
4.
That
the
Leather
(
which
vvas
not
spar'd
,
that
the
instrument
might
be
the
more
capacious
)
was
not
horny
or
very
stiff
,
but
limber
.
The
Reason
of
the
first
and
third
diversity
was
,
that
the
Bellows
might
be
capable
to
be
conveyed
into
our
Receiver
;
(
for
vvhich
purpose
also
,
if
there
had
appear'd
need
,
the
nose
might
have
been
made
in
the
uppermost
of
the
two
Boards
:
)
the
reason
of
the
2d
variation
was
,
that
the
instrument
might
be
the
more
stanch
:
and
of
the
4th
,
that
the
bases
of
the
Bellows
might
(
as
in
Organ-bellows
)
be
clapt
closer
together
,
and
harbour
less
Air
in
the
wrinkles
and
cavity
.
So
that
when
the
Bellows
vvere
opened
to
their
full
extent
,
by
drawing
up
the
upper
Basis
at
a
button
purposely
made
in
the
midst
of
it
,
the
Bellows
look'd
like
a
Cylinder
of
16
or
18
inches
high
;
upon
which
resemblance
I
take
the
liberty
to
call
both
the
Boards
(
as
Geometricians
do
both
the
circular
parts
of
a
Cylinder
)
Bases
.
But
though
these
were
made
by
an
Artificer
,
otherwise
dexterous
,
yet
it
not
being
his
Trade
to
make
Bellows
,
nor
any
other
mans
in
the
Town
I
then
was
in
,
he
could
not
make
them
so
Tite
,
but
that
in
spite
of
our
oyling
the
Leather
,
and
choaking
the
Seams
with
good
Cement
,
there
was
some
litle
and
unperceived
hole
or
cranny
,
whereby
some
Air
had
passage
when
the
nose
was
accurately
stopt
:
but
this
was
not
so
considerable
,
but
that
if
we
drew
up
the
upper
Basis
from
the
lower
,
the
external
Air
would
on
all
sides
press
the
Leather
inwards
,
and
so
make
the
shape
of
the
instrument
very
far
from
being
so
Cylindrical
,
as
it
would
be
if
the
nose
were
left
open
.
Wherefore
concluding
,
that
notwithstanding
this
imperfection
the
Bellows
would
serve
,
though
not
for
both
the
Experiments
I
design'd
,
yet
for
one
of
them
,
we
carefully
stopt
the
nose
,
after
we
had
approach'd
the
Bases
to
one
another
,
and
conveying
them
into
a
large
Receiver
,
it
quickly
appear'd
,
when
the
Pump
was
set
on
work
,
that
at
every
Exsuction
of
the
incumbent
Air
,
the
Air
harbour'd
in
the
folds
of
the
Leather
,
and
the
rest
of
the
litle
Cavitie
that
could
not
but
be
left
between
the
Bases
,
made
the
upper
of
those
Bases
manifestly
rise
,
though
its
weight
(
because
of
the
thickness
and
solidity
of
the
Wood
)
would
soon
after
depress
it
again
,
either
by
driving
out
some
of
the
Air
at
some
place
where
the
instrument
was
not
sufficiently
Tite
,
or
by
making
it
as
it
were
strain'd
through
the
Leather
it self
;
and
if
the
Pump
were
agitated
somewhat
faster
than
ordinary
,
the
Expansion
of
the
internal
Air
would
be
greater
than
could
be
rendred
quite
ineffectual
by
so
small
a
Leak
,
and
the
upper
part
of
the
Bellows
would
be
soon
rais'd
to
a
considerable
height
,
as
would
appear
more
evidently
if
we
hastily
let
in
the
external
Air
,
upon
whose
ingress
the
Bases
would
be
clapt
together
,
and
the
upper
of
them
a
good
vvay
deprest
.
So
that
the
imperfection
of
the
Bellows
made
the
Experiment
rather
more
than
less
concluding
;
for
since
there
was
no
external
force
applied
to
open
them
,
if
notwithstanding
that
some
of
the
included
Air
could
get
out
of
thē
,
yet
the
Spring
of
the
internal
Air
was
strong
enough
to
open
the
Bellows
when
the
ambient
Air
was
withdrawn
,
much
more
would
the
effect
have
been
produc'd
,
if
the
Bellows
had
been
perfectly
stanch
.
EXPERIMENT
XXXVIII
.
About
an
Attempt
to
examine
the
Motions
and
Sensibility
of
the
Cartesian
Materia
subtilis
,
or
the
Aether
,
with
a
pair
of
Bellows
(
made
of
a
Bladder
)
in
the
exhausted
Receiver
.
I
Will
not
now
discuss
the
Controversie
betwixt
some
of
the
Modern
Atomists
,
and
the
Cartesians
;
the
former
of
whom
think
,
that
betwixt
the
Earth
and
the
Stars
,
and
betwixt
these
themselves
there
are
vast
Tracts
of
Space
that
are
empty
,
save
where
the
beams
of
Light
do
pass
through
them
;
and
the
later
of
whom
tell
us
,
that
the
Intervals
betwixt
the
Stars
and
Planets
(
among
which
the
Earth
may
perhaps
be
reckon'd
)
are
perfectly
fill'd
,
but
by
a
Matter
far
subtiler
than
our
Air
,
which
some
call
Celestial
,
and
others
Aether
.
I
shall
not
,
I
say
,
engage
in
this
controversie
,
but
thus
much
seems
evident
,
That
if
there
be
such
a
Celestial
Matter
,
it
must
make
up
far
the
Greatest
part
of
the
Universe
known
to
us
.
For
the
Intersteller
part
of
the
world
(
if
I
may
so
stile
it
)
bears
so
very
great
a
proportion
to
the
Globes
,
and
their
Atmospheres
too
,
(
if
other
Stars
have
any
as
well
as
the
Earth
,
)
that
it
is
almost
incomparably
Greater
in
respect
of
them
,
than
all
our
Atmosphere
is
in
respect
of
the
Clouds
,
not
to
make
the
comparison
between
the
Sea
and
the
Fishes
that
swim
in
it
.
Wherefore
I
thought
it
might
very
vvell
deserve
a
heedful
Enquiry
,
whether
we
can
by
sensible
Experiments
(
for
I
hear
what
has
been
attempted
by
Speculative
Arguments
)
discover
any
thing
about
the
Existence
,
or
the
Qualifications
of
this
so
vast
Aether
:
and
I
hoped
our
Curiosity
might
be
somewhat
assisted
by
our
Engine
,
if
I
could
manage
in
it
such
a
pair
of
Bellows
as
I
design'd
.
For
I
propos'd
to
my self
to
fasten
a
convenient
weight
to
the
upper
Basis
,
and
clog
the
lower
with
another
,
great
enough
to
keep
it
Horizontal
and
immoveable
,
that
when
by
the
help
of
the
Turning-key
,
frequently
above
mention'd
,
the
upper
Basis
should
be
rais'd
to
its
full
height
,
the
cavity
of
the
Bellows
might
be
brought
to
its
full
dimensions
.
This
done
,
I
intended
to
exhaust
the
Receiver
,
and
consequently
the
thus
open'd
Bellows
with
more
than
ordinary
diligence
,
that
so
both
the
Receiver
and
they
might
be
carefully
freed
from
Air.
After
vvhich
I
purpos'd
to
let
go
the
upper
Base
of
the
Bellows
,
that
being
hastily
deprest
by
the
incumbent
Weight
,
it
might
speedily
enough
fall
down
to
the
lower
Basis
,
and
by
so
much
,
and
so
quickly
lessening
the
Cavity
,
might
expell
thence
the
Matter
(
if
any
were
)
before
contain'd
in
it
,
and
that
(
if
it
could
by
this
way
be
done
)
at
the
hole
of
a
slender
Pipe
,
fasten'd
either
near
the
bottom
of
the
Bellows
,
or
in
the
upper
Basis
:
against
or
over
the
orifice
of
which
Pipe
there
was
to
be
plac'd
at
a
convenient
distance
either
a
Feather
,
or
(
if
that
should
prove
too
light
)
the
Sail
of
a
litle
Wind-mill
made
of
Cards
,
or
some
other
light
body
,
and
fit
to
be
put
into
motion
by
the
impulse
of
any
Matter
that
should
be
forc'd
out
of
the
Pipe
.
By
this
means
it
seem'd
not
improbable
,
that
some
such
discovery
might
be
made
,
as
would
not
be
altogether
useless
in
our
Enquiry
.
For
if
notwithstanding
the
absence
of
the
Air
,
it
should
appear
by
the
Effects
that
a
stream
of
other
Matter
,
capable
to
set
visible
bodies
a
moving
,
should
issue
out
at
the
Pipe
of
the
comprest
Bellows
;
it
would
also
appear
,
that
there
may
be
a
much
subtiller
Body
than
common
Air
,
and
as
yet
unobserv'd
by
the
Vacuists
,
or
(
their
Adversaries
)
the
Schools
,
that
may
even
copiously
be
found
in
places
deserted
by
that
Air
;
and
that
it
is
not
safe
to
conclude
from
the
absence
of
the
Air
in
our
Receivers
,
and
in
the
upper
part
of
those
Tubes
where
the
Torricellian
Experiment
is
made
,
that
there
is
no
other
body
left
but
an
absolute
Vacuity
,
or
(
as
the
Atomists
call
it
)
a
vacuū
coacervatū
.
But
if
on
the
other
side
there
should
appear
no
motion
at
all
to
be
produc'd
,
so
much
as
in
the
Feather
,
it
seem'd
that
the
Vacuists
might
plausibly
argue
,
that
either
the
Cavity
of
the
Bellows
was
absolutely
empty
,
or
else
that
it
would
be
very
difficult
to
prove
by
any
sensible
Experiment
that
it
was
full
,
and
,
if
by
any
other
way
of
probation
it
be
demonstrable
,
that
it
was
replenish'd
with
Aether
,
we
that
have
not
yet
declar'd
for
any
party
,
may
by
our
Experiment
be
taught
to
have
no
confident
expectations
of
easily
making
it
sensible
by
Mechanical
Experiments
;
and
may
also
be
inform'd
,
that
t
is
really
so
subtle
and
yielding
a
Matter
,
that
does
not
either
easily
impell
such
light
bodies
as
even
Feathers
,
or
sensibly
resist
as
does
the
Air
it self
the
motions
of
other
bodies
through
it
,
and
is
able
without
resistance
to
make
its
passage
through
the
Pores
of
Wood
,
and
Leather
,
and
also
of
closer
bodies
,
which
we
find
not
that
the
Air
doth
in
its
Natural
or
wonted
state
penetrate
.
To
illustrate
this
last
Clause
I
shall
adde
,
that
to
make
the
Trial
more
accurate
,
I
wav'd
the
use
of
other
Bellows
,
(
especially
not
having
such
as
I
desired
,
)
&
caus'd
a
pair
of
small
Bellows
to
be
made
with
a
Bladder
,
as
a
Body
,
which
some
of
our
former
Experiments
have
evinc'd
to
be
of
so
close
a
Texture
,
that
Air
will
rather
break
it
than
passe
through
it
:
and
that
the
Bladder
might
no
where
loose
its
entireness
by
Seams
,
we
glued
on
the
two
Bases
,
the
one
to
the
bottom
,
and
the
other
to
the
opposite
part
of
it
,
so
that
the
Neck
came
out
at
a
hole
purposely
made
for
it
;
in
the
upper
Basis
,
and
into
the
Neck
it
was
easie
to
insert
what
pipe
we
thought
fit
,
binding
the
Neck
very
close
to
it
on
the
outside
.
We
had
likewise
Thoughts
to
have
another
pair
of
Tite
Bellows
made
with
a
very
light
Clack
in
the
lower
Basis
,
that
by
hastily
drawing
up
the
other
Basis
,
when
the
Receiver
and
Bellows
were
very
carefully
exhausted
,
we
might
see
by
the
rest
,
as
the
lifting
up
of
the
Clack
,
whether
the
subtle
Matter
that
was
expell'd
by
the
upper
Basis
in
its
Ascent
,
would
,
according
to
the
Modern
Doctrine
of
the
Circle
made
by
moving
Bodies
,
be
impell'd
up
or
not
.
We
also
thought
of
placing
the
litle
Pipe
of
the
Bladder-bellows
(
if
I
may
so
call
them
)
beneath
the
surface
of
Water
exquisitely
freed
from
Air
,
that
we
might
see
whither
upon
the
Depression
of
the
Bellows
by
the
incumbent
Weight
,
when
the
Receiver
was
carefully
exhausted
,
there
would
be
any
thing
expell'd
at
the
Pipe
,
that
would
produce
Bubbles
in
the
liquor
,
wherein
its
Orifice
was
immerst
.
To
bring
now
our
Conjectures
to
some
Trial
,
we
put
into
a
capp'd
Receiver
the
Bladder
accommodated
as
before
is
mentioned
,
and
though
we
could
have
wish'd
it
had
been
somewhat
larger
,
because
it
contain'd
but
between
half
a
Pint
and
a
Pint
,
yet
in
regard
it
was
fine
and
limber
,
and
otherwise
fit
for
our
Turn
,
we
resolv'd
to
try
how
it
would
do
;
and
to
depress
the
upper
Basis
of
these
litle
Bellows
the
more
easily
and
uniformly
,
we
cover'd
the
round
piece
of
Pastboard
,
that
made
the
upper
Basis
,
with
a
Pewter-plate
,
(
with
a
hole
in
it
for
the
neck
of
the
Bladder
;
)
which
nevertheless
upon
trial
prov'd
not
ponderous
enough
,
whereby
we
were
oblig'd
to
assist
it
by
laying
on
it
a
Weight
of
Lead
.
And
to
secure
the
above
mentioned
Feather
,
(
which
had
a
slender
and
flexible
Stem
,
and
was
left
broad
at
one
end
,
and
fastned
by
Cement
at
the
other
,
so
as
to
stand
with
its
broad
end
at
a
convenient
distance
just
over
the
Orifice
of
the
Pipe
,
)
from
being
blown
aside
to
either
hand
,
we
made
it
to
move
in
a
perpendicular
slit
in
a
piece
of
Pastboard
,
EXPERIMENT
XXXIX
.
About
a
further
attempt
to
prosecute
the
Inquiry
propos'd
in
the
foregoing
Experiment
.
COnsidering
with
my self
,
that
by
the
help
of
some
contrivances
not
difficult
,
a
Syringe
might
be
made
to
serve
,
as
far
as
our
present
occasion
required
,
in
stead
of
a
pair
of
Bellows
;
I
thought
it
would
not
be
improper
to
try
a
differing
,
and
,
in
some
regards
,
a
better
way
to
prosecute
an
attempt
,
which
seem'd
to
me
to
deserve
our
Curiosity
.
I
caus'd
then
to
be
made
,
All
these
things
being
done
,
and
the
handle
of
the
Rammer
being
tied
to
the
Turning-key
of
a
capp'd
Receiver
,
the
Syringe
and
its
Pedestal
were
inclosed
in
a
capacious
Receiver
,
(
for
none
but
such
a
one
could
contain
them
,
and
give
scope
for
the
Rammers
motions
,
)
and
the
Pump
being
set
on
worke
,
we
did
,
after
some
quantity
of
Air
was
drawn
out
,
raise
the
Sucker
a
litle
by
the
help
of
the
Turning-key
,
and
then
turning
the
same
Key
the
contrary
way
we
suffer'd
the
Weight
to
depress
the
Sucker
,
that
we
might
see
at
what
rate
the
Feather
would
be
blown
up
;
and
finding
that
it
was
impell'd
forceably
enough
,
we
caus'd
the
pumping
to
be
so
continued
,
that
a
pretty
many
pauses
were
made
,
during
each
of
which
we
rais'd
and
depress'd
the
Sucker
as
before
,
and
had
the
opportunity
to
observe
,
That
as
the
Receiver
was
more
and
more
exhausted
of
the
Air
,
so
the
Feather
was
less
and
less
briskly
driven
up
,
till
at
length
,
when
the
Receiver
was
well
emptied
,
the
usual
elevations
and
depressions
of
the
Sucker
would
not
blow
it
up
at
all
that
I
could
perceive
,
though
they
were
far
more
frequently
repeated
than
ever
before
;
nor
was
I
content
to
look
heedfully
my self
,
but
I
made
one
whom
I
had
often
imploy'd
about
Pneumatical
Experiments
to
watch
attentively
,
whilst
I
drew
up
,
and
let
down
the
Sucker
,
but
he
affirm'd
that
he
could
not
discern
the
least
beginning
of
Ascension
in
the
Feather
.
And
indeed
to
both
of
us
it
seem'd
,
that
the
litle
and
inconsiderable
motion
that
was
sometimes
(
not
alwayes
)
to
be
discern'd
in
the
Feather
,
proceeded
not
from
any
thing
that
issued
out
of
the
Pipe
,
but
from
some
litle
Shake
,
which
t
was
difficult
not
to
give
the
Syringe
and
Pedestal
,
by
the
raising
and
depressing
of
the
Sucker
.
And
that
which
made
our
Phaenomenon
the
more
considerable
,
was
,
that
the
Weight
that
carried
down
the
Sucker
being
still
the
same
,
and
the
motions
of
the
Turning-key
being
easie
to
be
made
equal
at
several
times
,
there
seem'd
no
reason
to
suspect
that
Contingencies
did
much
(
if
at
all
)
favour
the
success
;
but
there
hapned
a
thing
,
which
did
manifestly
enough
disfavour
it
.
For
I
remember
,
that
before
the
Syringe
was
put
into
the
Receiver
,
when
we
were
trying
how
the
Weight
would
depress
it
,
and
it
was
thought
that
though
the
Weight
were
conveniently
shap'd
,
yet
it
was
a
litle
of
the
least
;
I
would
not
alter
it
,
but
foretold
,
that
when
the
Air
in
the
Cavity
of
the
Syringe
(
that
now
resisted
the
quickness
of
its
descent
,
because
so
much
Air
could
not
easily
and
nimbly
get
out
at
so
small
a
Pipe
)
should
be
exhausted
with
the
other
Air
of
the
Receiver
,
the
elevated
Sucker
would
fall
down
more
easily
,
which
he
,
that
was
imploy'd
to
manage
the
Syringe
whilst
I
watch'd
the
Feather
,
affirm'd
himself
afterwards
to
observe
very
evidently
.
So
that
when
the
Receiver
was
exhausted
,
if
there
had
been
in
the
cavity
of
the
Syringe
a
matter
as
fit
as
Air
to
make
a
Wind
of
,
the
Blast
ought
to
have
been
Greater
,
because
the
celerity
that
the
Sucker
was
deprest
with
was
so
.
After
we
had
long
enough
tried
in
vain
to
raise
the
Feather
,
I
order'd
some
Air
to
be
let
into
the
Receiver
;
and
though
when
the
admitted
Air
was
but
very
litle
,
the
motions
of
the
Sucker
had
scarce
if
at
all
any
sensible
operation
upon
the
Feather
,
yet
when
the
quantity
of
Air
began
to
be
somewhat
considerable
,
the
Feather
began
to
be
a
litle
mov'd
upwards
,
and
so
by
letting
in
Air
not
all
at
once
but
more
and
more
from
time
to
time
,
and
by
moving
the
Sucker
up
and
down
in
the
intervals
of
those
times
of
admission
,
we
had
the
opportunity
to
observe
,
that
as
the
Receiver
had
more
Air
in
it
,
the
Feather
would
be
more
briskly
blown
up
.
But
not
content
with
a
single
Tryal
of
an
Experiment
of
this
consequence
,
we
caused
the
Receiver
to
be
again
exhausted
,
and
prosecuted
the
Tryal
with
the
like
success
as
before
,
onely
this
one
Circumstance
,
that
we
added
for
confirmation
,
may
be
befit
to
be
here
taken
notice
of
.
Having
,
after
the
Receiver
was
exhausted
,
drawn
up
and
let
fall
the
Sucker
divers
times
ineffectually
;
though
hitherto
we
had
not
usually
rais'd
it
any
higher
at
a
time
,
than
we
could
by
one
turn
of
the
hand
,
both
because
we
could
not
so
conveniently
raise
it
higher
by
the
Hand
alone
,
and
because
we
thought
it
unnecessary
,
since
that
height
suffic'd
to
make
the
Air
briskly
toss
up
the
Feather
;
yet
ex
abundanti
we
novv
took
an
instrument
that
was
pretty
long
and
fit
so
to
take
hold
on
the
Turning-key
,
that
we
could
easily
raise
the
Sucker
between
two
and
three
inches
(
by
our
Aestimate
)
at
a
time
,
and
nimbly
depress
it
again
;
and
for
all
this
,
which
would
much
have
increas'd
the
Blast
,
if
there
had
been
a
Matter
fit
for
it
in
the
Cavity
of
the
Syringe
,
we
could
not
sensibly
blow
up
the
Feather
,
till
we
had
let
a
litle
Air
into
the
Receiver
.
To
be
able
to
make
an
aestimate
of
the
Quantity
of
Air
pump'd
out
,
or
let
in
,
when
the
Feather
vvas
strongly
or
faintly
,
or
not
at
all
rais'd
by
the
fall
of
the
Sucker
;
vve
took
off
the
Receiver
,
and
convey'd
a
Gage
into
it
,
but
though
for
a
vvhile
vve
made
some
use
of
our
Gage
,
yet
a
mischance
befalling
it
before
the
Operation
was
quite
ended
,
I
shall
forbear
to
adde
any
thing
concerning
that
Tryal
,
and
proceed
to
say
something
of
another
Attempt
,
wherein
though
I
foresaw
and
met
with
such
difficulties
,
as
kept
me
from
doing
altogether
what
I
desired
,
yet
the
success
being
almost
as
good
as
could
be
expected
,
I
shall
venture
to
acquaint
Your
Lordship
with
the
Tryal
,
which
was
this
.
In
stead
of
the
hitherto
imploy'd
Pipe
of
Brass
,
there
was
well
fastned
(
with
Cement
)
to
the
Syringe
a
Pipe
of
Glass
,
whose
figure
differ'd
from
that
of
the
other
in
this
particular
,
that
the
shorter
(
or
remoter
)
Leg
of
our
new
Pipe
,
after
it
had
for
a
while
been
carried
parallel
to
the
other
Leg
,
was
bent
off
so
,
that
above
an
inch
and
a
half
of
it
tended
downwards
,
that
the
orifice
of
it
might
be
immerst
into
Water
contain'd
in
a
small
open
Jarr
.
The
design
of
which
contrivance
was
,
that
when
the
Receiver
should
be
well
exhausted
,
we
might
(
according
to
what
I
told
Your
Lordship
vvas
at
first
design'd
)
try
vvhether
by
the
raising
and
depressing
of
the
Sucker
any
such
Matter
would
be
driven
out
at
the
nose
of
the
Pipe
,
as
would
produce
bubbles
in
the
incumbent
Water
,
which
,
Air
(
though
highly
rarefied
,
perhaps
to
some
hundreds
of
times
beyond
its
wonted
Dimensions
,
)
is
capable
of
doing
.
And
I
choose
to
imploy
rather
Water
than
Quick-silver
,
because
though
by
using
the
later
I
might
hope
to
be
less
troubled
with
bubbles
,
yet
the
ponderousness
and
opacity
of
it
seem'd
to
outweigh
that
convenience
.
I
need
not
tell
Your
Lordship
,
that
in
other
respects
this
Experiment
was
made
like
the
former
,
so
that
I
shall
mention
onely
its
peculiarities
,
which
were
,
That
as
the
Air
was
pump'd
out
of
the
Receiver
,
that
in
the
Glass
pipe
made
its
way
through
the
Water
in
Bubbles
,
and
a
litle
Air
having
once
by
a
small
Leak
got
in
,
and
forc'd
some
of
the
Water
out
of
the
Jarr
into
the
pipe
,
when
the
Receiver
was
again
vvell
emptied
,
both
that
Water
and
even
the
litle
quantity
of
stagnant
Water
,
that
was
contain'd
in
the
immerst
part
of
the
Pipe
,
produc'd
so
many
bubbles
of
several
sizes
,
as
quite
disturb'd
our
Observations
.
Wherefore
we
let
alone
the
Receiver
,
exhausted
as
it
was
,
for
6
or
7
hours
,
to
give
the
Water
time
to
be
freed
from
Air
,
and
then
causing
what
Air
might
have
stolen
in
to
be
again
pump'd
out
,
till
we
had
perceiv'd
by
the
Gage
that
the
Receiver
was
well
exhausted
,
we
caus'd
the
Sucker
(
of
the
Syringe
)
to
be
rais'd
and
deprest
diverse
times
,
and
though
even
then
a
Bubble
vvould
now
and
then
make
our
Observations
troublesome
,
and
less
certain
,
yet
it
seem'd
to
us
,
that
when
we
were
not
thus
confounded
,
we
sometimes
observed
that
the
elevation
and
fall
of
the
Sucker
,
though
reiterated
,
did
not
drive
out
at
the
Pipe
any
thing
that
made
any
discernable
bubbles
in
the
incumbent
Water
;
for
though
there
would
appear
now
and
then
some
small
bubbles
on
the
surface
of
the
Water
,
yet
I
could
not
perceive
that
the
Matter
that
made
them
,
issued
out
at
the
Pipe
;
and
some
of
them
manifestly
proceeded
from
Aerial
Particles
,
till
then
lurking
in
the
Water
,
as
I
concluded
from
the
place
and
time
of
their
rising
.
But
this
Non-eruption
of
bubles
at
the
nose
of
the
Pipe
,
vvas
not
that
which
gave
me
the
most
of
satisfaction
.
For
at
length
both
I
and
another
had
the
opportunity
to
observe
the
Water
in
the
immerst
part
of
the
Pipe
,
which
was
very
slender
,
to
be
about
an
inch
higher
than
the
rest
of
the
stagnant
Water
,
and
to
continue
at
that
height
or
place
in
the
Pipe
,
though
the
Sucker
vvere
divers
times
together
rais'd
and
depress'd
by
Guess
between
2
and
three
inches
at
a
time
.
Which
seem'd
to
argue
,
either
that
there
was
a
vacuum
in
the
cavity
of
the
Syringe
,
or
else
that
if
it
were
full
of
Aether
,
that
body
vvas
so
subtle
,
that
the
impulse
it
received
from
the
falling
Sucker
vvould
not
make
it
displeace
a
very
litle
Thread
(
perhaps
not
exceeding
a
Grain
in
Weight
)
of
Water
that
vvas
in
the
slender
Pipe
,
though
it
appear'd
by
the
bubbles
,
that
sometimes
disclos'd
themselves
in
the
Water
,
after
the
Receiver
had
been
exhausted
,
that
far
more
Water
vvould
be
displac'd
and
carried
up
by
a
small
bubble
consisting
of
such
rarified
Air
,
that
according
to
my
Aestimate
the
Aerial
particles
of
it
did
not
,
before
the
Pump
vvas
begun
to
be
set
on
vvork
,
take
up
in
the
Water
a
five-hundredth
part
of
the
quantity
of
a
Pins
head
.
But
whilst
we
were
considering
what
to
do
further
in
our
Tryal
,
a
litle
Air
,
that
strain'd
in
at
some
small
undiscoverable
Leak
,
drove
the
Water
into
the
emptied
part
of
the
Pipe
,
and
put
an
end
for
that
time
to
our
Tryal
,
which
had
been
too
toylsome
to
invite
us
then
to
reiterate
it
.
I
had
indeed
thoughts
of
prosecuting
the
Enquiry
,
by
dropping
from
the
top
of
the
exhausted
Receiver
light
Bodies
conveniently
shap'd
,
to
be
turn'd
round
,
or
otherwise
put
out
of
their
simplest
motion
of
Descent
,
if
they
met
with
any
resistance
in
their
fall
;
and
by
making
such
Bodies
move
Horizontally
and
otherwise
in
the
Receiver
,
as
vvould
probably
discover
whither
they
were
assisted
by
the
medium
:
and
other
contrivances
and
wayes
I
had
in
my
thoughts
,
whereby
to
prosecute
our
Enquiry
,
but
vvanting
time
for
other
Experiments
,
I
could
not
spare
so
much
as
was
necessary
to
exhaust
large
Receivers
so
diligently
,
as
such
nice
Trials
would
exact
;
and
therefore
I
resolv'd
to
desist
,
till
I
had
more
leisure
than
I
then
had
,
(
or
have
since
been
Master
of
.
)
In
the
interim
,
thus
much
we
seem
to
have
already
discovered
by
our
past
Tryals
,
that
if
when
our
Vessels
are
very
diligently
freed
from
Air
,
they
are
full
of
Aether
,
that
Aether
is
such
a
body
,
as
will
not
be
made
sensibly
to
move
a
light
Feather
by
such
an
impulse
as
would
make
the
Air
manifestly
move
it
,
not
onely
whilst
t
is
no
thinner
than
common
Air
,
but
when
t
is
very
highly
rarified
,
(
which
,
if
I
mistake
not
,
it
was
in
our
Experiment
so
much
,
as
to
be
brought
to
take
up
above
an
hundred
times
more
room
than
before
.
)
And
one
thing
more
we
gain'd
by
the
Tryal
made
with
water
,
namely
a
clear
confirmation
of
what
I
deliver'd
in
the
34th
Experiment
,
about
the
cause
of
the
Suction
that
is
made
by
Syringes
;
for
Your
Lordship
may
remember
,
that
at
the
close
of
the
Experiment
we
have
all
this
while
been
reciting
,
I
observ'd
,
that
when
the
external
Air
was
so
very
well
withdrawn
,
the
pulling
up
of
the
Sucker
would
not
make
the
stagnant
Water
,
that
the
Pipe
of
the
Syringe
was
immerst
in
,
to
ascend
one
inch
,
or
so
much
as
the
tenth
part
of
it
.
EXPERIMENT
XL.
About
the
falling
,
in
the
Exhausted
Receiver
,
of
a
light
Body
,
fitted
to
have
its
motion
visibly
varied
by
a
small
resistance
of
the
Air.
PArtly
to
try
whether
in
the
space
deserted
by
the
Air
,
drawn
out
of
our
Receivers
,
there
would
be
any
thing
more
fit
to
resist
the
motion
of
other
light
Bodies
through
it
,
than
in
the
former
Experiment
we
found
It
to
impell
them
into
motion
;
and
partly
for
another
purpose
to
be
mention'd
by
and
by
,
we
made
the
following
Tryals
.
We
took
a
Receiver
,
which
,
though
less
tall
than
we
would
have
had
,
was
the
longest
we
could
procure
:
and
that
we
might
be
able
,
not
so
properly
to
let
down
as
,
to
let
fall
a
Body
in
it
,
we
so
fastned
a
small
pair
of
Tobacco-Tongs
to
the
inside
of
the
Receivers
Brass-Cover
,
that
by
moving
the
Turning-key
,
we
might
by
a
string
tied
to
one
part
of
them
,
open
the
Tongs
,
which
else
their
own
Spring
would
keep
shut
.
This
being
done
,
the
next
thing
was
to
provide
a
Body
,
which
vvould
not
fall
down
like
a
Stone
,
or
another
dead
Weight
through
the
Air
,
but
would
in
the
manner
of
its
descent
shew
,
that
its
motion
was
somewhat
resisted
by
the
Air
;
vvherefore
that
vve
might
have
a
Body
that
vvould
be
turn'd
about
Horizontally
(
as
it
were
)
in
its
fall
,
we
thought
fit
to
joyn
Cross-wise
four
broad
and
light
Feathers
(
each
about
an
Inch
long
)
at
their
Quils
with
a
litle
Cement
,
into
vvhich
vve
also
stuck
perpendicularly
a
small
Label
of
Paper
,
about
an
8th
of
an
inch
in
breadth
,
and
somewhat
more
in
height
,
by
vvhich
the
Tongues
might
take
hold
of
our
light
Instrument
vvithout
touching
the
Cement
,
which
else
might
stick
to
them
.
By
the
help
of
this
small
piece
of
Paper
,
But
when
after
this
,
the
Feathers
being
plac'd
as
before
,
we
repeated
the
Experiment
by
carefully
pumping
out
the
Air
,
neither
I
nor
any
of
the
By-standers
could
perceive
any
thing
of
Turning
in
the
descent
of
the
Feathers
;
and
yet
for
further
security
we
let
them
fall
twice
more
in
the
unexhausted
Receiver
,
and
found
them
to
turn
in
falling
as
before
;
whereas
when
we
did
a
3d
d
time
let
them
fall
in
the
well
exhausted
Receiver
,
they
fell
after
the
same
manner
as
they
had
done
formerly
,
when
the
Air
,
that
vvould
by
its
resistance
have
turn'd
them
round
,
vvas
remov'd
out
of
their
vvay
.
Note
1.
though
(
as
I
intimated
above
)
the
Glass
,
vvherein
this
Experiment
was
made
,
were
nothing
near
so
tall
as
I
would
have
had
it
,
yet
it
was
taller
than
any
of
our
ordinary
Receivers
,
it
being
in
height
about
22
inches
.
2.
One
that
had
had
more
leisure
and
conveniency
,
might
have
made
a
more
commodious
Instrument
than
that
we
made
use
of
:
for
being
accidentally
visited
by
that
Sagacious
Mathematician
Dr
Wren
,
and
speaking
to
him
of
this
matter
,
he
was
pleas'd
with
great
dexterity
as
well
as
readiness
to
make
me
a
little
Instrument
of
Paper
,
on
which
,
when
t
was
let
fall
,
the
resistance
of
the
Air
had
so
manifest
an
operation
,
that
I
should
have
made
use
of
it
in
our
Experiment
,
had
it
not
been
casually
lost
when
the
ingenious
Maker
was
gone
out
of
these
parts
.
3.
Though
I
have
but
briefly
related
our
having
so
order'd
the
matter
,
that
we
could
conveniently
let
fall
a
Body
in
the
Receiver
when
very
well
exhausted
,
yet
to
contrive
and
put
in
practice
what
was
necessary
to
perform
this
,
was
not
so
very
easie
,
and
it
would
be
difficult
to
describe
it
circumstantially
without
very
many
words
;
for
which
reason
I
forbear
an
account
,
that
would
prove
too
tedious
to
us
both
.
4.
What
has
been
hitherto
related
,
was
done
in
prosecution
of
but
one
of
the
two
Designs
I
aim'd
at
in
the
foregoing
Contrivance
,
by
which
I
intended
,
if
I
could
have
procured
a
Receiver
tall
enough
,
to
try
whether
Bodies
(
some
very
light
,
and
some
heavier
)
being
let
fall
when
the
Air
was
very
diligently
pump'd
out
,
would
not
descend
somewhat
faster
than
if
the
Receiver
were
full
of
Air.
But
though
I
had
provided
a
Pendulum
that
vibrated
quarters
of
Seconds
,
yet
the
Glass
being
no
higher
than
it
was
,
the
Descent
even
of
our
Feathers
took
up
so
litle
time
,
that
even
this
Pendulum
was
of
no
use
;
onely
it
seem'd
to
all
of
us
that
were
present
at
making
the
above
recited
Tryals
,
that
when
the
Feathers
were
let
fall
at
such
times
as
the
Air
(
that
would
have
turn'd
them
round
in
their
descent
)
was
removed
,
they
came
to
the
bottom
sensibly
sooner
than
at
other
times
.
But
when
we
shall
have
opportunity
to
repeat
the
Experiment
in
taller
Glasses
,
and
to
make
some
variation
of
it
,
I
hope
to
be
able
to
give
Your
Lordship
a
fuller
satisfaction
about
this
Particular
.
And
in
the
mean
while
I
shall
forbear
to
examine
whether
the
Air
might
somewhat
retard
the
descent
of
the
Feathers
upon
some
other
account
,
or
meerly
upon
that
of
its
being
a
medium
not
quite
devoid
of
Gravity
.
Annotations
.
1.
But
here
I
must
be
so
sincere
as
to
inform
Your
Lordship
,
that
this
40th
Experiment
seem'd
not
to
prove
so
much
as
did
the
foregoing
made
with
the
Syringe
:
for
being
suspicious
that
,
to
make
the
feathered
body
above
mentioned
turn
in
its
fall
,
there
would
need
a
resistance
not
altogether
inconsiderable
,
I
caus'd
the
Experiment
to
be
repeated
,
when
the
Receiver
was
by
our
Aestimate
(
which
was
not
made
at
random
neither
)
litle
or
nothing
more
than
half
exhausted
,
and
yet
the
remaining
Air
was
too
far
rarified
to
make
the
falling
Body
manifestly
turn
.
2.
And
yet
perchance
it
would
have
hapned
otherwise
,
if
the
Receiver
had
been
tall
enough
;
which
though
I
had
not
then
leasure
and
conveniency
to
make
it
,
yet
it
will
not
be
amiss
to
let
Your
Lorship
know
by
what
means
we
did
,
that
it
might
be
somewhat
fit
to
make
the
recited
Experiment
and
some
others
,
bring
it
to
the
height
it
had
,
which
did
considerably
exceed
that
of
the
tallest
Glass
we
could
then
procure
.
To
lengthen
our
Receiver
therefore
,
we
thought
fit
to
try
,
whether
we
could
not
close
enough
fasten
to
the
bottom
of
it
,
with
very
good
Cement
a
Cylindrical
Pipe
of
Laton
,
whose
upper
orifice
should
have
neer
the
same
breadth
with
the
bottom
of
the
Glass
.
And
though
this
Contrivance
seem'd
liable
to
a
couple
of
not
mean
difficulties
;
The
one
,
that
the
Laton
being
every
where
bended
,
and
in
some
places
necessary
to
be
souder'd
,
it
would
be
very
hard
(
as
indeed
we
found
it
)
to
avoid
some
small
cracks
and
leaks
:
And
the
other
,
that
if
the
metalline
Pipe
were
wide
enough
,
so
great
and
heavy
a
pillar
of
the
Atmosphere
would
come
to
bear
against
it
,
as
to
press
it
inwards
,
if
not
also
to
break
it
;
yet
we
hoped
we
should
be
able
to
obviate
both
of
these
inconveniences
.
Against
the
first
of
which
our
Remedy
was
,
to
Coat
over
very
carefully
the
whole
Pipe
with
the
same
close
Cement
,
wherewith
we
fastned
it
to
the
Glass
Receiver
.
And
against
the
Second
,
we
provided
a
litle
Frame
consisting
of
divers
small
Iron
Bars
fastned
together
;
which
Frame
(
though
t
were
not
too
wide
to
go
into
the
Cylinder
of
Laton
,
yet
it
)
was
wide
enough
to
be
so
neer
it
on
the
inside
,
that
(
though
the
weight
of
the
Atmosphere
should
,
as
we
feared
,
press
the
Laton
so
as
to
make
it
yield
inward
,
yet
)
it
could
make
it
bend
no
further
than
the
Iron-frame
would
permit
;
which
was
not
far
enough
to
spoile
either
the
Receiver
or
the
Experiment
.
And
this
not
unpleasant
phaenomenon
would
somewhat
surprise
unaccustomed
Spectators
,
that
when
after
the
Receiver
had
been
very
well
exhausted
,
the
external
Air
was
permitted
to
return
,
there
would
be
heard
during
some
time
,
from
the
metalline
part
of
the
Receiver
,
divers
Sounds
brisk
enough
,
which
would
make
an
odd
Cracking
noise
proceeding
from
the
Laton-plate
,
which
having
been
forceably
,
though
but
slowly
,
bent
inwards
by
the
predominant
Pressure
of
the
Atmosphere
,
was
now
assisted
by
the
Pressure
of
the
returning
Air
,
to
regain
its
former
Figure
.
And
as
I
thought
not
fit
to
omit
this
Circumstance
,
because
it
confirms
the
practicableness
of
the
Remedy
propos'd
against
the
2d
Inconvenience
;
so
I
thought
fit
to
mention
this
way
of
enlarging
and
heightning
Receivers
,
because
what
we
have
related
seems
to
give
Grounds
of
hoping
that
this
Contrivance
may
be
made
good
use
of
in
divers
other
Tryals
,
and
particularly
in
attempts
to
make
Receivers
capacious
enough
to
contain
larger
Animals
,
and
perhaps
even
a
Boy
,
or
a
Man
.
In
order
to
some
of
which
purposes
we
indeavoured
to
get
an
improvement
made
of
our
Metalline
Cylinder
by
additional
contrivances
;
but
could
not
(
where
we
then
were
)
get
Artificers
,
that
would
perform
what
was
directed
.
EXPERIMENT
XLI
.
About
the
propagation
of
Sounds
in
the
Exhausted
Receiver
.
TO
make
some
further
Observation
than
is
mention'd
in
the
[
*
](A28949-e10950-b)
*
Page
the
105.
106.
Publish'd
Experiments
,
about
the
Production
and
conveying
of
Sounds
in
a
Glass
whence
the
Air
is
drawn
out
,
we
imploy'd
a
Contrivance
,
of
which
(
because
we
make
use
of
it
in
divers
other
Experiments
)
it
will
be
requisite
to
give
Your
Lordship
here
some
short
description
.
We
caus'd
to
be
made
at
the
Turners
a
Cylinder
of
Box
,
or
the
like
close
and
firme
Wood
,
and
of
a
length
suitable
to
that
of
the
Receiver
it
was
to
be
imploy'd
in
.
Out
of
the
lower
Basis
of
this
Cylinder
(
vvhich
might
be
about
an
inch
and
a
half
in
Diameter
)
there
came
a
smaller
Cylinder
or
Axle-tree
not
a
quarter
so
thick
as
the
other
,
To
come
now
to
our
Tryal
about
Sounds
,
vve
caus'd
a
Hand-Bell
(
vvhose
Handle
and
Clapper
were
taken
away
)
to
be
so
fastned
to
a
strng
Wire
,
that
,
one
end
of
the
Wire
being
made
fast
in
the
Trencher
,
the
other
end
,
vvhich
vvas
purposely
bent
downwards
,
took
hold
of
the
Bell.
In
another
hole
,
made
in
the
circumference
of
the
same
Trencher
,
vvas
vvedg'd
in
(
vvith
a
wooden
Peg
)
a
Steel-spring
,
to
whose
upper
part
was
tied
a
Gad
of
Iron
or
Steel
,
less
than
an
inch
long
,
but
of
a
pretty
thickness
.
The
length
of
this
Spring
was
such
,
as
to
make
the
upper
part
of
the
Hammer
(
if
I
may
so
call
the
piece
of
Iron
)
of
the
same
height
with
the
Bell
,
The
Trencher
being
thus
furnisht
and
plac'd
in
a
Capp'd
Receiver
,
(
as
You
know
,
for
brevity
sake
,
we
use
to
call
one
that
is
fitted
with
one
or
other
of
the
Brass
Covers
,
often
mentioned
already
,
)
the
Air
was
diligently
pump'd
out
;
and
then
,
by
the
help
of
the
Turning-key
,
the
Vertical
Cylinder
was
made
to
go
round
,
by
which
means
as
often
as
either
of
a
couple
of
stiff
Wires
,
or
small
Pegs
,
that
were
fastned
at
right
Angles
into
holes
,
made
not
far
from
the
bottom
of
the
Cylinder
,
pass'd
(
under
the
Bell
,
and
)
by
the
lately
mentioned
Spring
;
they
forceably
did
in
their
passage
bend
it
from
the
Bell
,
by
which
means
,
as
soon
as
the
Wire
was
gone
by
,
and
the
Spring
ceas'd
to
be
press'd
,
it
would
fly
back
with
violence
,
enough
to
make
the
Hammer
give
a
smart
stroak
upon
the
Bell.
And
by
this
means
we
could
both
continue
the
Experiment
at
discretion
,
and
make
the
percussions
more
equally
strong
than
it
would
otherwise
have
been
easie
to
do
.
The
event
of
our
Tryal
was
;
That
,
when
the
Receiver
was
vvell
emptied
,
it
sometimes
seem'd
doubtful
,
especially
to
some
of
the
By-standers
,
whether
any
Sound
were
produc'd
or
no
;
but
to
me
for
the
most
part
it
seem'd
,
that
after
much
attention
I
heard
a
Sound
,
that
I
could
but
just
hear
;
and
yet
,
vvhich
is
odd
,
me
thought
it
had
somewhat
of
the
nature
of
Shrilness
in
it
,
but
seem'd
(
which
is
not
strange
)
to
come
from
a
good
way
off
.
Whether
the
often
turning
of
the
Cylindrical
Key
kept
the
Receiver
from
being
so
stanch
as
else
it
vvould
have
been
,
upon
vvhich
score
some
litle
Air
might
insinuate
it self
,
I
shall
not
positively
determine
:
but
to
discover
vvhat
interest
the
Presence
or
the
absence
of
the
Air
might
have
in
the
Loudness
or
Lowness
of
the
Sound
,
I
caus'd
the
Air
to
be
let
into
the
Receiver
,
not
all
at
once
but
at
several
times
,
with
competent
intervals
between
them
;
by
which
Expedient
it
was
easie
to
observe
,
that
the
Vertical
Cylinder
being
still
made
to
go
round
,
when
a
litle
Air
vvas
let
in
,
the
stroak
of
the
Hammer
upon
the
Bell
(
that
before
could
now
and
then
not
be
heard
,
and
for
the
most
part
be
but
very
scarcely
heard
)
began
to
be
easily
heard
.
And
when
a
litle
more
Air
was
let
in
,
the
Sound
grew
more
and
more
audible
,
and
so
increased
,
till
the
Receiver
was
again
replenished
with
Air
;
though
even
then
(
that
we
omit
not
That
phaenomenon
)
the
Sound
was
observ'd
to
be
much
less
loud
than
when
the
Receiver
was
not
interpos'd
between
the
Bell
and
the
Ear.
And
whereas
in
the
already
publish'd
Physico-Mechanical
Experiments
I
acquainted
Your
Lordship
with
what
I
observ'd
about
the
Sound
of
an
ordinary
Watch
in
the
Exhausted
Receiver
,
I
shall
now
adde
,
that
That
Experiment
was
repeated
not
long
since
,
with
the
addition
of
suspending
in
the
Receiver
a
Watch
,
with
a
good
Alarum
,
which
was
purposely
so
set
,
that
it
might
,
before
it
should
begin
to
ring
,
give
us
time
to
cement
on
the
Receiver
very
carefully
,
exhaust
it
very
diligently
,
and
settle
our selves
in
a
silent
and
attentive
posture
.
And
to
make
this
Experiment
in
some
respect
more
accurate
than
the
others
we
made
of
Sounds
,
we
secur'd
our selves
against
any
leaking
at
the
Top
,
by
imploying
a
Receiver
that
was
made
all
of
one
piece
of
Glass
,
(
and
consequently
had
no
Cover
cemented
on
to
it
,
)
being
furnish'd
onely
within
(
when
't
was
first
blown
)
with
a
Glass-knob
or
Button
,
to
which
a
string
might
be
tied
.
And
because
it
might
be
suspected
,
that
if
the
Watch
were
suspended
by
its
own
Silver
Chain
,
the
tremulous
motion
of
its
sounding
Bell
might
be
propagated
by
that
Metalline
Chain
to
the
upper
part
of
the
Glass
;
to
obviate
this
as
well
as
we
could
,
we
hung
the
Watch
,
not
by
its
Chain
,
but
a
very
slender
Thread
,
whose
upper
end
was
fastned
to
the
newly
mentioned
Glass-button
.
These
things
being
done
,
and
the
Air
being
carefully
pump'd
out
,
we
silently
expected
the
time
when
the
Alarum
should
begin
to
ring
,
which
't
was
easie
to
know
by
the
help
of
our
other
Watches
;
but
not
hearing
any
noise
so
soon
as
we
expected
,
it
would
perhaps
have
been
doubted
whether
the
Watch
continued
Going
,
if
for
prevention
we
had
not
order'd
the
matter
so
,
that
we
could
discern
it
did
not
stand
still
.
Wherefore
I
desir'd
an
ingenious
Gentleman
to
hold
his
Ear
just
over
the
Button
,
at
which
the
Watch
was
suspended
,
and
to
hold
it
also
very
near
to
the
Receiver
,
upon
which
he
told
us
that
he
could
perceive
,
and
but
just
perceive
something
of
Sound
,
that
seem'd
to
come
from
far
;
though
neither
we
that
listned
very
attentively
near
other
parts
of
the
Receiver
,
nor
he
,
if
his
Ears
were
no
more
advantaged
in
point
of
position
than
Ours
,
were
satisfied
that
we
heard
the
Watch
at
all
.
Wherefore
ordering
some
Air
to
be
let
in
,
we
did
by
the
help
of
attention
begin
to
hear
the
Alarum
;
whose
Sound
was
odd
enough
,
and
,
by
returning
the
Stop-cock
to
keep
any
more
Air
from
getting
in
,
we
kept
the
Sound
thus
low
for
a
pretty
while
,
after
which
a
little
more
Air
,
that
was
permitted
to
enter
,
made
it
become
more
audible
;
and
when
the
Air
was
yet
more
freely
admitted
,
the
by
standers
could
plainly
hear
the
noise
of
the
yet
continuing
Alarum
at
a
considerable
distance
from
the
Receiver
.
From
what
has
hitherto
been
related
we
may
learn
what
is
to
be
thought
of
what
is
delivered
by
the
Learned
Mersennus
,
in
that
Book
of
his
Harmonicks
,
where
he
makes
this
to
be
the
first
Proposition
.
Sonus
à
Campanis
,
vel
aliis
corporibus
non
solùm
producitur
in
illo
vacuo
(
quicquid
tandem
illud
sit
,
)
quod
fit
in
Tubis
Hydrargyro
plenis
,
posteaque
depletis
,
sed
etiam
idem
acumen
,
quod
in
Aere
libero
vel
clauso
penitus
observatur
&
auditur
.
For
the
proof
of
which
Assertion
,
not
long
after
,
he
speaks
thus
:
Porro
variis
Tubis
,
quorum
extremis
lagenae
vitreae
adglutinantur
,
observari
Campanas
in
illo
vacuo
appensas
,
propriisque
malleis
percussas
idem
penitus
acumen
retinere
,
quod
in
Aere
libero
habent
:
atque
soni
magnitudinem
ei
sono
,
qui
fit
in
Aere
quem
Tubus
clausus
includit
,
nihil
cedere
.
But
though
our
Experiments
sufficiently
manifest
that
the
presence
or
absence
of
the
common
Air
is
of
no
small
importance
as
to
the
conveying
of
Sounds
,
and
that
the
interposition
of
Glass
may
sensibly
weaken
them
;
yet
so
diligent
and
faithful
a
Writer
as
Mersennus
deserves
to
be
favourably
treated
:
and
therefore
I
shall
represent
on
his
behalf
,
that
what
he
sayes
may
well
enough
have
been
true
,
as
far
as
could
be
gathered
from
the
Tryals
he
made
.
For
First
,
t
is
no
easie
matter
,
especially
for
those
that
have
not
peculiar
and
very
close
Cements
,
to
keep
the
Air
quite
out
for
any
considerable
time
in
vessels
consisting
of
divers
pieces
,
such
as
he
appears
to
have
made
use
of
.
And
next
,
the
bigness
of
the
Bell
in
reference
to
the
capacity
of
the
exhausted
Glass
,
and
the
thickness
of
the
Glass
,
and
the
manner
whereby
the
Bell
was
fastned
to
the
inside
of
the
Glass
,
and
the
Hammer
or
Clapper
was
made
to
strike
,
may
much
vary
the
Effect
of
the
Tryal
,
for
Reasons
easie
to
be
gather'd
out
of
the
past
Discourse
,
and
therefore
not
needful
to
be
here
insisted
on
.
And
upon
this
Account
we
chose
to
make
our
Experiment
,
with
sounds
that
should
not
be
strong
or
loud
,
and
to
produce
them
after
such
a
manner
,
as
that
as
litle
shaking
as
could
be
might
be
given
by
the
sounding
Body
to
the
Glass
't
was
included
in
.
The
Proposal
made
by
the
same
Mersennus
,
to
have
those
that
have
industry
enough
,
try
whether
a
Bag-pipe
will
be
made
to
afford
the
same
Sound
as
in
the
open
Air
,
in
such
Vessels
as
he
used
for
his
Bels
,
though
he
seems
to
think
it
would
succeed
,
is
that
which
Your
Lordship
will
not
,
I
presume
,
sollicite
me
to
make
Tryal
of
,
if
You
remember
what
is
related
in
the
almost
immediately
foregoing
Experiments
,
shewing
,
That
we
could
make
nothing
come
out
of
the
Cavity
of
a
pair
of
Bellows
,
that
had
force
enough
to
blow
away
a
Feather
,
when
that
Cavity
was
freed
from
Air
;
as
the
Bagpipe
would
be
by
the
same
operation
,
that
empties
the
Glass
that
contains
it
,
or
else
the
Sound
would
not
be
made
in
such
a
Vacuum
as
the
scope
of
the
Experiment
requires
.
If
I
had
had
Conveniency
,
I
would
have
made
some
Tryals
by
conveying
a
small
string'd
Instrument
(
perhaps
some
such
as
they
commonly
call
a
Kit
)
exactly
tun'd
,
into
a
large
Receiver
,
and
then
upon
briskly
striking
the
String
of
a
bigger
Instrument
,
(
tuned
,
as
they
speak
,
to
an
Unison
to
(
or
with
)
that
of
the
smaller
Instrument
)
I
should
have
taken
notice
,
whether
the
Sound
would
have
been
so
uniformly
propagated
,
notwithstanding
the
Interposition
of
the
Glass
Receiver
,
as
sensibly
to
shake
the
included
String
;
in
order
to
the
discerning
of
which
,
a
bended
piece
of
Straw
,
or
Feather
,
or
some
such
light
body
,
was
to
be
hors'd
upon
the
String
to
be
shaken
.
I
also
intended
,
in
case
the
string
were
made
to
move
,
to
make
the
like
Tryal
after
the
Receiver
was
diligently
exhausted
.
And
lastly
I
design'd
to
try
,
whether
two
Unison
strings
of
the
same
Instruments
,
or
of
a
couple
to
be
plac'd
in
the
same
Receiver
,
would
,
when
the
Air
(
which
is
the
usual
medium
of
Sounds
)
was
well
pump'd
out
,
yet
maintain
such
a
Sympathy
(
as
t
is
call'd
,
)
that
upon
the
motion
of
the
one
,
the
other
would
also
be
made
to
stir
:
Which
Tryals
may
be
varied
,
by
imploying
for
the
external
Instrument
another
in
stead
of
a
stringed
one
.
And
because
Contraries
(
as
is
vulgarly
noted
)
serve
to
illustrate
each
other
,
I
thought
to
subjoyn
,
to
the
Tryals
above
related
,
about
the
propagation
of
Sounds
in
a
thinner
medium
than
the
Air
,
some
observations
about
the
conveyance
of
them
through
that
thicker
medium
,
Water
;
but
having
unluckily
mislaid
my
Notes
upon
that
Subject
,
I
cannot
at
present
acquaint
Your
Lordship
with
what
I
intended
,
but
must
defer
the
doing
it
,
till
I
shall
have
recovered
Them
.
EXPERIMENT
XLII
.
About
the
breaking
of
a
Glass-drop
in
an
Exhausted
Receiver
.
YOu
know
,
that
among
the
Causes
that
have
been
propos'd
of
the
strange
flying
of
a
Glass-drop
into
a
multitude
of
pieces
,
when
the
slender
Stem
of
it
comes
to
be
broken
off
,
One
of
the
least
improbable
was
taken
from
the
Pressure
of
the
Air
:
as
if
that
within
the
poreous
(
and
as
't
were
honey-comb'd
)
inside
of
the
Glass
,
being
highly
rarified
when
the
drop
of
melted
Glass
fell
into
the
Water
at
its
first
formation
,
it
was
forc'd
to
continue
in
that
praeternatural
state
of
Expansion
by
the
hardness
and
closeness
of
the
external
Case
of
Glass
,
that
inclos'd
the
Pithlike
part
(
if
I
may
so
call
it
;
)
so
that
upon
the
breaking
off
a
part
of
this
solid
Case
at
the
Stem
,
the
external
Air
gaining
access
,
and
finding
in
the
Spungy
part
very
litle
resistance
from
the
highly
rarified
and
consequently
weaken'd
Air
included
there
,
rushes
in
with
such
violence
,
as
to
shiver
the
Glass-drop
into
a
multitude
of
pieces
.
I
shall
not
now
trouble
Your
Lordship
with
the
mention
of
what
may
be
alleadg'd
to
question
this
Hypothesis
,
especially
if
it
be
compared
with
that
accurate
Account
of
the
Phaenomena
of
such
Glass-drops
,
which
was
sometime
since
presented
to
the
Society
by
that
great
Ornament
of
it
,
Sr
Robert
Moray
.
But
I
shall
onely
say
in
this
place
,
that
when
I
consider'd
,
that
if
the
Dissilition
of
the
Glass
would
succeed
when
the
Air
was
pump'd
out
of
it
,
it
would
be
hard
to
ascribe
that
Effect
to
the
irruption
of
the
external
Air
,
I
thought
fit
to
try
what
would
happen
,
if
a
Glass-drop
were
broken
in
our
exhausted
Receiver
.
And
accordingly
did
,
though
not
without
some
difficulty
,
so
order
the
matter
,
that
the
blunter
part
of
the
Glass-drop
was
fastned
to
a
stable
Body
(
convey'd
into
the
Receiver
,
)
and
the
crooked
Stem
was
tyed
to
one
end
of
a
string
,
whose
other
end
was
fastned
to
the
Turning-key
;
by
which
means
,
when
the
Air
had
been
diligently
pump'd
out
,
the
Stem
was
(
by
shortning
the
string
)
broken
off
,
and
the
Glass
drop
was
shatter'd
into
a
thousand
pieces
.
This
Experiment
was
long
after
repeated
with
the
like
success
,
and
having
at
that
time
no
Gage
to
try
how
far
the
Air
had
been
drawn
out
,
we
let
the
external
Air
impell
up
the
Water
out
of
the
Pump
into
the
Receiver
,
and
thereby
found
,
that
That
vessel
had
not
been
negligently
exhausted
.
EXPERIMENT
XLIII
.
About
the
production
of
Light
in
the
exhausted
Receiver
.
I
Presume
,
I
need
not
put
Your
Lordship
in
mind
,
that
divers
attempts
were
made
to
try
,
whether
either
a
Flame
,
or
kindled
Coals
would
be
made
to
continue
for
sometime
burning
in
our
Receiver
:
But
those
Tryals
making
it
evident
,
that
it
would
be
either
impossible
,
or
very
difficult
to
produce
any
durable
Light
,
without
the
presence
of
the
Air
,
by
the
burning
of
bodies
;
I
thought
it
not
amiss
,
considering
the
Nobleness
of
Light
,
to
make
trial
,
whether
it
might
be
otherwise
produc'd
in
our
exhausted
Receiver
;
since
whether
or
no
the
Attempts
should
prove
successful
,
the
Event
would
probably
be
instructive
.
For
as
t
is
the
property
of
Light
,
when
t
is
produc'd
,
to
be
discoverable
by
it self
;
so
in
such
a
Tryal
as
we
intended
,
it
would
teach
something
concerning
Light
,
to
find
that
the
absence
of
the
Air
would
or
would
not
hinder
it
from
being
produc'd
.
In
prosecution
of
this
Design
,
knowing
that
hard
Sugar
,
being
nimbly
scrap'd
with
a
knife
,
will
afford
a
sparkling
Light
,
so
that
now
&
then
one
would
think
that
sparks
of
Fire
fly
from
it
;
we
caus'd
a
good
lump
of
hard
Loaf-sugar
to
be
conveniently
and
firmly
placed
in
the
cavity
of
our
capp'd
Receiver
,
and
to
the
vertical
Cylinder
formerly
mentioned
we
caus'd
to
be
fastned
some
pieces
of
a
Steel-spring
,
which
being
not
very
thick
,
might
in
their
passage
along
the
Sugar
,
grate
,
or
rub
forceably
against
it
,
and
then
the
Receiver
being
diligently
exhausted
in
the
Night-time
,
and
in
a
dark
Room
,
the
vertical
Cylinder
(
whose
lower
Axis
was
inserted
into
the
often
mentioned
Trencher
)
was
made
for
a
pretty
while
to
move
round
by
the
help
of
the
Turning-key
,
EXPERIMENT
XLIV
.
About
the
production
of
a
kind
of
Halo
,
and
Colours
in
the
Exhausted
Receiver
.
VVE
took
a
large
inverted
Cucurbite
for
a
Receiver
,
which
being
so
well
wip'd
both
within
and
without
as
to
be
very
clear
,
allow'd
me
to
observe
,
and
to
make
others
do
so
too
,
That
when
the
Pump
began
to
be
set
a
work
,
if
I
caus'd
a
pretty
large
Candle
to
be
held
on
the
other
side
of
the
Glass
,
upon
the
turning
of
the
Stop-cock
to
let
the
Air
out
of
the
Receiver
into
the
Cylinder
,
the
Glass
would
seem
to
be
full
of
Fumes
,
and
there
would
appear
about
the
Flame
of
the
Candle
,
seen
through
them
,
a
kind
of
Halo
,
that
at
first
commonly
was
between
Blew
and
Green
,
and
after
some
Sucks
would
be
of
a
Reddish
or
Orange
colour
,
and
both
very
vivid
.
The
production
of
this
Meteor
(
if
I
may
so
call
it
)
was
,
according
to
my
conjecture
,
made
on
some
such
score
as
this
.
That
the
Cement
being
somewhat
soft
and
new
(
as
is
convenient
for
this
Experiment
)
abounds
with
Turpentine
,
and
having
a
litle
(
as
well
to
fasten
on
the
Receiver
,
as
for
the
other
purpose
)
apply'd
to
it
a
hot
Iron
,
whereby
the
Cement
was
both
softned
and
heated
,
it
seem'd
rational
to
expect
,
That
upon
the
withdrawing
of
the
Air
in
the
Receiver
,
the
Aerial
Particles
in
the
Cement
,
freed
from
their
former
Pressure
,
would
extricate
themselves
,
and
with
the
looser
steams
of
the
Turpentine
and
perhaps
of
the
Bees-wax
would
with
a
kind
of
Explosion
expand
themselves
in
the
Receiver
,
and
by
their
interposition
between
the
Light
and
the
Eye
exhibit
those
delightful
Colours
we
had
seen
.
To
confirme
which
,
I
afterwards
found
,
that
by
watchfully
observing
it
I
could
plainly
enough
perceive
the
colouring
steams
,
just
upon
the
turning
of
the
Stopcock
,
to
fly
up
from
the
Cement
towards
the
top
of
the
Glass
;
and
if
we
continued
Pumping
,
the
Receiver
would
grow
clearer
,
and
the
Colours
more
dilute
,
(
till
we
had
occasion
to
put
on
the
Receiver
,
and
heat
the
Cement
afresh
:
)
of
which
the
reason
might
be
,
partly
that
the
Aerial
and
Volatile
Particles
of
the
upper
part
of
the
Cement
did
in
that
tract
of
time
spend
themselves
more
and
more
;
and
partly
,
because
the
Agitation
they
receiv'd
from
the
heat
communicated
by
the
Iron
did
continually
decay
.
Not
to
mention
,
that
when
the
Receiver
is
more
exhausted
,
the
want
of
Air
makes
it
more
difficult
for
Steams
to
be
supported
,
and
as
it
were
swim
up
and
down
in
it
.
But
for
farther
Confirmation
,
I
caus'd
some
Cement
to
be
put
into
a
small
Crucible
,
warm
enough
to
melt
it
;
and
conveying
this
into
a
clear
Receiver
of
a
convenient
shape
and
size
,
I
caus'd
the
Pump
to
be
set
a
work
;
whereupon
it
appear'd
manifestly
enough
,
That
upon
the
opening
of
the
Stop-cock
to
let
out
the
Air
,
the
Steams
would
copiously
be
thrown
about
from
the
Crucible
into
the
capacity
of
the
Receiver
,
and
would
,
after
having
a
litle
play'd
there
,
fall
down
again
.
But
in
these
apparitions
the
Vividness
,
and
sometimes
the
Kind
of
the
exhibited
Colours
seem'd
much
to
depend
upon
divers
circumstances
,
such
as
the
degrees
of
Heat
,
the
bigness
and
shape
of
the
Receiver
,
the
quantity
of
Air
that
yet
remain'd
unpump'd
out
,
and
the
nature
of
the
Cement
its
self
;
which
last
particular
I
the
rather
mention
,
because
,
though
I
were
hinder'd
from
doing
it
,
I
had
thoughts
to
try
a
suspicion
I
had
,
that
by
varying
the
Materials
expos'd
to
this
kind
of
operation
,
some
pretty
variety
might
be
made
in
the
phaenomena
of
the
Experiment
.
Whether
or
no
the
Apparition
of
Whiteness
,
or
Light
,
that
we
sometimes
hapned
to
take
notice
of
divers
years
agoe
,
and
have
mentioned
in
the
already
[
*
](A28949-e11490-b)
*
pag.
156.
&c
▪
publish'd
part
of
our
Physico-mechanical
Experiments
,
may
be
partly
(
though
not
entirely
)
referr'd
to
some
of
the
Cements
I
then
imploy'd
,
differing
from
those
I
now
use
most
,
and
to
the
unheeded
temper
of
those
Cements
,
as
to
Warmth
,
and
degrees
of
Softness
,
is
a
Doubt
that
further
Observation
may
possibly
enable
us
to
determine
.
EXPERIMENT
XLV
.
About
the
production
of
Heat
by
Attrition
in
the
Exhausted
Receiver
.
THe
opinion
that
ascribes
the
Incalescence
of
solid
Bodies
,
struck
or
rubb'd
hard
against
one
another
to
the
attrition
or
vehement
agitation
of
the
intercepted
Air
,
is
famous
and
received
enough
to
seem
worthy
of
a
particular
Examination
.
But
I
confess
to
Your
Lordship
,
that
t
was
not
any
thing
relating
to
this
Opinion
that
chiefly
induc'd
me
to
make
the
Experiment
I
am
now
about
to
give
an
account
of
;
for
I
thought
it
might
be
usefull
to
more
purposes
than
one
,
to
be
able
to
produce
by
Attrition
a
somewhat
durable
Heat
even
in
our
exhausted
Receiver
:
and
therefore
though
't
were
easie
to
foresee
,
that
it
would
prove
no
easie
task
,
yet
we
thought
fit
to
attempt
it
in
spight
of
the
difficulties
met
with
at
our
first
Tryal
.
In
what
way
and
with
what
success
we
afterwards
made
this
attempt
,
I
now
proceed
to
relate
.
Cross
the
stable
Trencher
,
Besides
these
things
,
a
litle
fine
powder
of
Emery
was
put
between
the
convex
and
concave
pieces
of
Brass
,
to
make
them
more
congruous
,
and
facilitate
the
motion
that
was
to
be
made
;
and
there
was
fastned
to
the
upper
part
of
the
Turning
key
a
good
Wimble
,
without
which
we
presum'd
the
turning
of
the
Key
would
not
produce
a
sufficient
motion
:
in
order
to
the
making
of
which
,
it
was
,
after
the
first
Tryal
,
judged
requisite
to
have
a
strong
man
,
that
was
us'd
to
exercise
his
hands
and
armes
in
Mechanical
labours
,
upon
which
account
we
sent
for
a
certain
Lock-smith
,
that
was
a
lusty
and
dexterous
fellow
.
All
things
that
were
thought
necessary
being
thus
in
readiness
,
and
a
Mercurial
Gage
being
convey'd
into
the
Receiver
,
we
caus'd
the
Air
to
be
diligently
pump'd
out
;
and
then
the
Smith
was
order'd
to
turn
the
Wimble
,
and
to
continue
to
lean
a
litle
on
it
,
that
he
might
be
sure
to
keep
the
Turning-key
from
being
at
all
lifted
up
by
the
formerly
mentioned
Spring
.
Whilst
this
man
with
much
nimbleness
and
strength
was
moving
the
Wimble
,
I
watch'd
the
Gage
,
to
observe
whether
the
agitation
of
the
Stop-cock
,
and
consequently
the
Engine
,
did
not
prejudice
the
Experiment
;
and
for
greater
caution
I
caus'd
the
Pump
to
be
almost
all
the
while
kept
at
work
,
though
that
seem'd
not
so
necessary
.
When
the
Turner
of
the
Wimble
was
almost
out
of
Breath
,
we
let
in
for
hast
the
Air
at
the
Cover
of
the
Receiver
by
lifting
up
the
Turning-key
,
and
nimbly
removing
the
Receiver
we
felt
the
pieces
of
Brass
,
betwixt
whom
the
Attrition
had
been
made
,
and
,
as
we
expected
,
found
both
of
them
very
sensibly
warm
.
But
being
willing
to
confirm
the
Experiment
by
a
second
Tryal
,
which
we
hoped
might
,
after
the
Experience
taught
us
by
the
first
,
be
somewhat
better
performed
,
we
caus'd
the
Smith
,
after
he
had
well
refresh'd
himself
with
rest
and
drink
,
to
lay
hold
of
the
Wimble
again
,
when
the
Gage
made
it
appear
that
the
Receiver
was
well
exhausted
,
so
that
by
further
Pumping
the
Quick-silver
seem'd
not
to
be
further
deprest
.
And
in
this
2d
Tryal
the
nimble
Smith
plaid
his
part
so
well
,
(
the
Pump
in
the
mean
while
not
being
neglected
,
)
that
when
we
did
as
before
hastily
let
in
the
Air
,
and
take
out
the
Bodies
that
had
been
rubb'd
against
one
another
,
they
were
both
of
them
(
especially
the
uppermost
)
so
hot
,
that
I
could
not
endure
to
hold
my
hand
on
either
of
them
,
and
they
did
for
a
considerable
time
retain
a
not
inconsiderable
degree
of
Warmth
.
The
same
day
I
caus'd
to
be
made
at
the
Turners
two
bodies
of
Wood
,
for
size
and
shape
like
those
of
Brass
we
had
just
before
imploy'd
;
the
upper
of
these
was
of
hard
Oak
,
the
other
of
Beech
,
(
such
a
difference
between
Woods
,
to
be
heated
by
mutual
Attrition
,
being
thought
to
be
an
advantageous
circumstance
;
)
but
though
the
Wimble
was
swiftly
turn'd
as
before
,
and
that
by
the
same
Person
,
nevertheless
the
Wood
seem'd
not
to
me
(
for
all
the
By-standers
were
not
of
my
opinion
)
to
have
manifestly
acquired
any
Warmth
;
and
yet
that
there
had
been
a
considerable
Attrition
,
appear'd
by
the
great
Polish
which
part
of
the
Wood
had
evidently
acquir'd
,
vvhich
made
me
suspect
,
that
though
the
Wood
seem'd
dry
enough
,
yet
it
might
not
really
be
so
,
notwithstanding
the
contrary
was
affirm'd
to
me
:
but
not
being
willing
to
sit
down
with
a
single
Tryal
,
I
caus'd
the
Experiment
to
be
repeated
with
more
obstinacy
than
before
,
the
effect
of
which
was
,
that
the
Wood
,
especially
the
upper
piece
of
it
,
vvas
brought
to
a
Warmth
unquestionably
sensible
.
EXPERIMENT
XLVI
.
About
the
slaking
of
Quick-Lime
in
the
Exhausted
Receiver
.
THe
several
Scopes
I
aim'd
at
in
making
the
following
Tryal
are
not
necessary
to
be
here
particularly
taken
notice
of
.
But
one
of
them
may
be
guess'd
at
by
the
subsequence
of
this
Experiment
to
that
immediately
foregoing
,
and
the
phaenomena
of
it
may
be
mentioned
in
this
Epistle
upon
the
account
of
their
being
exhibited
by
our
Engine
.
We
took
in
an
Evaporating
Glass
a
convenient
quantity
of
Water
,
and
having
convey'd
it
into
a
Receiver
,
and
well
drawn
out
the
Air
,
we
let
down
into
it
by
the
Turning-key
a
lump
of
strong
Lime
,
about
the
bigness
of
a
Pipin
;
and
observ'd
not
that
at
the
first
immersion
,
nor
for
some
while
after
,
there
appear'd
any
considerable
number
of
Bubbles
,
but
within
about
1/4
of
an
hour
,
as
I
guess'd
it
,
the
Lime
began
(
the
Pump
having
been
and
being
still
ply'd
from
time
to
time
)
to
slack
with
much
violence
,
and
with
bubbles
wonderfully
great
,
that
appear'd
at
each
new
Exuction
,
so
that
the
inside
of
the
Receiver
(
though
pretty
large
)
was
at
length
lin'd
with
Lime-water
,
and
a
great
part
of
the
mixture
did
from
time
to
time
overflow
the
vessel
,
that
had
purposely
been
but
little
fill'd
;
nor
did
any
thing
but
our
weariness
put
a
period
to
the
bubling
of
the
mixture
,
whose
heat
was
sensible
even
on
the
outside
of
the
Receiver
,
and
which
continued
considerably
hot
in
the
Evaporating
Glass
for
¼
of
an
hour
(
as
I
conjectured
)
after
the
Receiver
was
removed
.
Note
,
That
the
Lime
imployed
about
this
Experiment
was
of
a
very
good
and
strong
kind
(
made
of
hard
stones
,
)
and
not
such
Lime
,
made
of
Chalk
,
as
is
commonly
used
at
London
,
which
probably
would
not
have
been
strong
enough
to
have
afforded
us
the
same
phaenomenon
.
EXPERIMENT
XLVII
.
About
an
attempt
made
to
measure
the
force
of
the
Spring
of
included
Air
,
and
examine
a
Conjecture
about
the
difference
of
its
strength
in
unequally
broad
mouth'd
Vessels
.
THough
several
of
the
foregoing
Tryals
have
sufficiently
manifested
that
the
Spring
of
the
Air
in
its
natural
or
wonted
state
,
hath
a
force
very
considerable
,
and
indeed
much
Greater
than
men
seem
to
have
hitherto
believed
;
Yet
I
could
not
hope
by
any
of
these
Experiments
to
determine
by
any
known
weight
,
how
Great
that
force
is
,
so
as
to
conclude
that
it
is
equivalent
to
such
a
Weight
,
as
so
many
Pounds
,
Ounces
,
&c.
and
to
no
more
.
Wherefore
among
the
Uses
I
had
design'd
to
make
of
our
Syringe
,
formerly
often
mentioned
,
it
was
One
,
to
try
if
by
the
help
of
that
Instrument
,
we
could
determine
somewhat
near
(
for
no
more
was
to
be
expected
)
how
much
Weight
a
Cylinder
of
uncomprest
Air
included
in
it
,
and
consequently
of
the
same
Diameter
vvith
the
cavity
of
the
Barrel
,
would
be
able
to
sustain
or
also
to
lift
up
.
In
order
to
this
Tryal
,
1.
we
provided
a
stable
Pedestal
,
or
Frame
,
wherein
the
Syringe
might
be
kept
firm
,
and
erected
.
Next
,
vve
also
provided
a
Weight
of
Lead
shap'd
like
our
Brass-hoop
,
or
Ring
,
[
*
](A28949-e11800-b)
*
Expe.
the
Vth.
formerly
describ'd
,
that
by
the
advantage
of
its
figure
it
might
be
made
to
hang
down
by
strings
from
the
top
of
the
Handle
of
the
Rammer
,
and
so
press
evenly
enough
on
all
sides
,
without
making
the
upper
part
of
the
instrument
top-heavy
.
3.
We
took
care
to
leave
,
between
the
bottom
of
the
Syringe
(
which
was
firmly
clos'd
with
strong
Cement
)
and
that
part
of
it
where
the
Sucker
was
,
a
convenient
quantity
of
Air
,
to
expand
its
self
,
and
lift
up
the
Weight
,
when
the
Air
external
to
that
included
Air
should
be
pump'd
out
of
the
Receiver
:
And
lastly
,
the
Handle
of
the
Rammer
(
from
which
the
Annular
weight
lately
spoken
of
depended
)
was
so
fastned
to
the
Turning-key
of
the
Cover
of
the
Receiver
,
that
the
Weight
might
not
compress
the
Air
included
in
the
Syringe
,
but
leave
it
in
its
natural
state
or
wonted
Laxity
,
till
the
Air
were
withdrawn
from
the
Receiver
.
But
notwithstanding
all
this
,
when
we
actually
tryed
the
Experiment
,
That
hapned
which
I
feared
.
For
though
by
this
method
the
included
Air
would
well
enough
lift
up
a
Weight
of
7
or
8
pound
,
yet
when
the
Rammer
came
to
be
clogg'd
with
so
considerable
a
Weight
,
as
my
scope
in
making
the
Experiment
required
,
the
Instrument
prov'd
not
so
stanch
,
but
that
it
was
easier
for
some
particles
of
Air
to
force
themselves
a
passage
,
and
get
away
between
the
Sucker
and
the
inside
of
the
Barrel
,
than
to
heave
up
so
great
a
Weight
.
And
yet
I
have
thought
fit
to
relate
the
Experiment
thus
particularly
,
because
,
if
an
exact
Syringe
can
be
procured
,
(
which
I
fear
will
be
very
difficult
,
but
do
not
think
impossible
,
this
seems
to
be
one
of
the
likeliest
and
least
exceptionable
wayes
I
know
,
of
measuring
the
force
of
the
Airs
Spring
.
But
despairing
to
get
such
a
Syringe
,
as
I
desir'd
,
in
the
place
where
I
then
was
,
I
bethought
my self
of
another
way
,
by
which
I
hop'd
to
be
able
(
though
not
to
arrive
at
an
exact
knowledge
of
the
full
force
of
the
Airs
Spring
,
yet
)
at
least
to
approach
nearer
it
than
I
have
been
able
to
do
by
the
help
of
the
Syringe
.
For
this
purpose
considering
with
my self
,
that
if
a
convenient
quantity
of
Air
were
included
in
a
fine
small
Bladder
,
the
sides
of
it
would
hinder
the
Air
from
getting
away
,
and
the
limberness
of
them
would
permit
the
Air
to
accommodate
it self
and
the
Bladder
to
the
Figure
of
a
Cylindrical
vessel
,
into
which
it
might
be
put
.
Wherefore
with
much
adoe
I
procured
to
be
made
by
a
person
exercised
in
Turning
a
couple
of
hollow
Cylinders
,
whose
sides
were
of
a
sufficient
thickness
,
(
that
they
might
resist
the
pressure
of
the
Air
to
be
imprisoned
in
them
,
)
and
of
such
differing
breadths
,
that
the
first
had
but
one
inch
in
Diameter
,
and
the
2d
two
;
their
depths
being
also
unequal
,
that
the
one
might
receive
a
much
larger
Bladder
than
the
other
.
With
the
lesser
of
these
(
which
was
very
carefully
Turned
)
I
made
a
diligent
Tryal
;
whose
Circumstances
I
cannot
now
acquaint
Your
Lordship
with
,
the
Paper
,
wherein
they
vvere
amply
recorded
,
having
been
vvith
other
Notes
belonging
to
this
Continuation
unluckily
lost
:
but
the
most
considerable
things
in
the
Event
were
,
That
t
was
very
difficult
to
procure
a
Bladder
small
and
fine
enough
for
that
litle
Cylinder
;
and
that
one
,
which
at
length
we
procured
,
would
not
continue
stanch
for
many
Tryals
,
but
would
after
a
vvhile
part
with
a
litle
Air
in
the
well
exhausted
Receiver
,
when
t
was
clog'd
with
the
utmost
Weight
it
could
sustain
:
but
whilst
it
continued
stanch
vve
made
one
fair
Tryal
vvith
it
,
from
vvhence
vve
concluded
,
that
a
Cylinder
of
Air
of
but
an
inch
in
Diameter
,
and
lesse
than
two
inches
in
length
,
was
able
to
raise
visibly
(
though
but
a
litle
)
a
Weight
of
above
ten
Pounds
,
(
I
speak
of
Averdupoiz
vveights
,
vvhere
a
Pound
contains
16
ounces
.
)
The
manner
of
making
this
Experiment
,
and
the
cautions
us'd
in
judging
of
it
,
Your
Lorship
may
learn
by
the
recital
of
the
subsequent
Tryal
;
my
Notes
about
which
were
not
so
unfortunate
as
those
that
concern'd
the
former
.
Into
a
hollow
Cylinder
of
Wood
of
four
inches
in
depth
,
Wherefore
we
substituted
for
a
7
pound
weight
one
that
was
estimated
at
14
,
(
for
then
we
had
not
a
Ballance
strong
enough
to
weigh
it
with
,
)
and
using
the
same
Bladder
we
repeated
the
Experiment
,
onely
having
a
care
to
support
a
litle
the
uppermost
Weight
by
the
Turning-key
,
till
the
Bladder
had
attained
its
expansion
;
and
then
the
Weight
being
gently
let
go
,
depress'd
not
the
Plug
so
low
,
but
that
we
could
yet
see
the
mark
on
it
,
(
which
yet
was
all
we
could
do
,
)
though
that
part
of
the
Plug
,
where
the
mark
vvas
,
vvere
manifestly
more
deprest
than
the
other
.
For
the
clearing
up
of
some
particulars
relating
to
this
Tryal
,
we
will
subjoyn
the
following
Notes
.
1.
The
Plug
is
to
be
so
fitted
to
the
Cavity
of
the
Cylinder
,
as
easily
to
slip
up
and
down
in
it
,
without
Grating
against
the
sides
of
it
,
lest
it
needlesly
increase
the
resistance
of
the
Weight
to
be
rais'd
.
And
this
Plug
ought
to
be
of
a
convenient
length
,
as
about
an
inch
and
1/2
at
least
,
that
it
may
be
the
fitter
to
help
to
reduce
the
Bladder
by
compression
into
a
somewhat
Cylindrical
shape
,
and
yet
that
it
may
not
be
thrust
in
too
deep
by
the
incumbent
Weight
;
and
that
the
Weight
might
rest
more
firmly
upon
it
,
there
was
a
broad
and
strong
Ledge
made
at
the
top
of
it
,
by
which
it
might
lean
on
every
side
upon
the
brim
of
the
hollow
Cylinder
.
2.
Before
the
Instrument
was
conveyed
into
the
Receiver
,
the
Bladder
(
which
ought
to
be
of
a
just
size
,
and
not
full
blown
,
and
of
a
fine
and
limber
contexture
)
was
put
into
the
Cylinder
,
and
by
divers
gradual
(
but
not
immoderate
)
compressions
was
reduc'd
to
conform
its
self
,
as
much
as
might
be
,
to
the
Cylindrical
shape
of
the
containing
vessel
.
And
then
the
Weight
being
put
on
,
and
taken
off
again
,
there
was
a
mark
(
in
the
form
of
an
horizontally
plac'd
Arch
)
made
with
Ink
,
where
the
edge
of
the
brim
of
the
hollow
Cylinder
did
almost
touch
the
Plug
.
This
we
thought
necessary
to
do
,
to
avoid
a
mistake
;
for
we
must
not
judg
,
that
all
the
Weight
,
that
might
be
rais'd
by
our
Bladder
,
may
pass
for
the
Weight
sought
after
by
our
Experiment
;
since
the
Air
in
the
Bladder
is
by
reason
of
the
incumbent
weight
more
comprest
than
t
was
before
,
and
consequently
its
being
able
to
heave
up
a
Great
weight
will
not
infer
,
that
our
common
Air
is
able
in
its
natural
state
(
as
they
call
it
)
to
exert
so
Great
a
strength
;
that
Weight
being
onely
to
be
lookt
on
as
rais'd
or
sustain'd
by
the
uncomprest
Air
,
that
is
rais'd
or
sustain'd
when
the
Plug
is
lifted
up
to
the
mark
,
since
till
then
the
Spring
of
the
Air
does
but
bring
it
back
from
its
new
state
of
adventitious
compression
to
its
natural
or
wonted
Laxity
.
3.
When
,
after
the
operation
was
ended
,
we
took
the
Bladder
out
of
the
vessel
,
it
had
obtain'd
a
form
Cylindrical
enough
,
and
though
it
could
be
but
2
inches
in
Diameter
,
yet
it
was
so
litle
as
to
be
but
half
an
inch
more
long
than
broad
.
4.
The
reason
why
I
chose
to
have
the
two
Cylinders
made
of
the
unequal
Diameters
above
mentioned
,
was
to
examine
,
as
far
as
by
this
way
I
could
,
a
conjecture
I
had
,
that
the
force
of
the
Spring
of
differing
Cylinders
of
Air
to
lift
up
solid
Weights
,
would
,
at
the
very
first
raising
of
the
Weights
,
be
in
duplicate
proportion
to
the
Diameters
of
their
Cylinders
,
(
those
Diameters
being
proportionable
to
the
Areas
of
the
plain
Superficies
,
against
which
the
Air
does
immediately
press
,
)
without
very
much
considering
the
inequality
that
may
be
between
the
quantity
of
the
several
parcels
of
Air
,
whose
pressures
are
compared
.
But
t
is
to
be
remembred
,
that
I
said
at
the
very
first
raising
of
the
weights
,
because
presently
after
That
,
the
quantity
of
the
parcels
of
Air
may
be
very
considerable
:
for
,
as
I
have
shewn
in
another
Treatise
,
two
very
unequal
quantities
of
Air
being
made
by
their
Expansion
to
possess
two
equal
spaces
,
the
lesser
quantity
of
Air
must
be
much
more
rarified
in
proportion
than
the
greater
;
and
consequently
,
(
to
bring
this
home
to
our
present
Argument
)
though
both
be
lifted
up
¼
or
½
of
an
inch
,
the
Spring
of
a
very
litle
Air
must
be
much
more
weakned
than
that
of
a
very
considerable
Quantity
,
and
so
it
cannot
continue
to
lift
up
its
weight
,
as
the
above
mentioned
proportion
would
(
if
it
were
not
for
this
Advertisement
)
seem
to
require
.
Taking
then
our
conjecture
in
the
sense
now
declared
,
the
success
of
our
Tryals
is
agreeable
to
it
,
inviting
us
to
conclude
,
that
the
Air
in
the
Bladder
,
which
was
but
two
inches
in
Diameter
,
was
able
by
its
Pressure
to
countervaile
the
weight
of
42
pound
,
which
is
about
four
times
the
weight
that
we
lately
observ'd
the
Spring
of
a
Cylinder
of
Air
of
one
inch
in
Diameter
to
be
able
to
lift
up
.
For
though
,
according
to
what
we
have
formerly
said
of
a
duplicate
proportion
,
42
pound
seems
to
be
somewhat
more
than
ought
to
have
been
lifted
up
in
the
Cylinder
of
two
inches
bore
,
when
that
of
one
inch
lifted
up
not
much
above
10
pound
;
yet
this
disagrees
not
with
the
Hypothesis
,
if
we
consider
that
the
substance
of
the
Bladder
straitens
the
cavity
of
the
smaller
Cylinder
in
a
Greater
proportion
than
that
of
the
bigger
.
5.
Though
we
have
thus
(
as
far
as
the
Instruments
we
were
able
to
procure
would
assist
us
)
measured
the
Pressure
of
included
Air
,
yet
I
must
not
forbear
to
advertise
Your
Lordship
,
that
considering
what
I
formerly
observ'd
to
You
about
the
weight
of
an
Atmospherical
Pillar
of
an
inch
in
Diameter
,
I
cannot
but
think
,
that
if
a
Cylinder
,
or
other
convenient
instrument
,
exactly
Tite
,
can
be
procured
,
the
Spring
of
an
Aerial
Cylinder
will
appear
to
be
Greater
than
we
found
it
by
the
foregoing
Tryals
;
in
which
I
consider
that
,
not
to
mention
the
resistance
of
the
Bladder
its
self
,
the
membraneous
substance
that
lin'd
the
Cylinders
(
though
t
were
very
thin
and
fine
)
could
not
but
somewhat
straiten
their
Cavities
,
and
consequently
somewhat
(
though
not
much
)
lessen
the
Diameters
of
the
included
Aerial
Cylinders
.
6.
To
all
these
Notes
I
must
adde
this
Advertisement
,
That
it
may
be
therefore
the
more
difficult
in
such
Tryals
as
ours
to
ascertain
the
force
of
the
Airs
Spring
,
because
,
that
Air
its
self
when
t
is
included
,
being
shut
up
with
the
Pressure
of
the
Atmosphere
upon
it
,
t
is
probable
,
that
since
that
Pressure
(
as
we
have
shewn
)
is
not
at
all
times
the
same
,
the
Spring
of
the
included
Air
will
accordingly
be
varied
.
And
,
if
my
memory
fail
me
not
,
when
the
lately
recited
Experiments
were
made
,
our
Barometer
declared
the
Atmosphere
to
be
somewhat
light
.
From
what
has
been
hitherto
delivered
,
this
may
result
;
that
t
is
likely
,
that
the
Spring
of
an
Aerial
Cylinder
an
inch
broad
,
may
be
able
to
sustain
,
if
not
raise
,
a
pretty
deal
more
than
ten
pound
Weight
;
and
that
the
past
Tryals
,
without
determining
that
the
Air
can
raise
no
more
than
in
them
it
did
,
do
,
at
least
,
prove
that
it
can
raise
up
as
much
Weight
as
we
have
related
,
since
we
actually
found
it
to
do
so
.
EXPERIMENT
XLVIII
.
About
an
easie
way
of
making
a
small
quantity
of
included
Air
raise
in
the
exhausted
Receiver
50
or
60
pound
,
or
a
greater
weight
.
I
Would
very
willingly
have
further
prosecuted
the
foregoing
Tryals
,
to
see
how
far
the
lately
propos'd
Conjecture
or
Hypothesis
would
hold
;
but
was
hindered
by
the
want
of
Receivers
tall
and
capacious
enough
to
contain
the
Weights
,
that
such
an
attempt
required
:
but
remembring
that
there
were
not
any
Experiments
made
in
our
Engine
,
that
appear'd
more
strange
to
the
Generality
of
Spectators
,
and
serv'd
more
to
give
them
a
high
opinion
of
the
Airs
Spring
,
than
those
wherein
they
saw
solid
Bodies
actually
lifted
up
by
it
,
and
remembring
,
that
I
had
lying
by
me
a
Brass
vessel
,
(
which
had
been
bespoken
for
another
Experiment
,
for
which
the
Workmen
had
not
made
it
fit
,
)
I
thought
it
not
amiss
to
imploy
it
about
making
a
Tryal
very
easie
,
and
yet
fit
to
be
shewn
to
Strangers
,
to
convince
them
,
that
the
Spring
of
the
Air
is
a
much
more
considerable
thing
than
they
imagined
.
We
took
then
a
Brass
vessel
made
like
a
Cylinder
,
and
having
one
of
his
Orifices
exactly
covered
with
a
flat
Plate
very
firmly
fastned
to
it
,
the
other
Orifice
being
wide
open
.
The
depth
of
this
vessel
was
4
inches
,
and
the
Diameter
should
have
been
precisely
(
but
wanted
about
a
quarter
of
an
inch
of
)
4
inches
.
To
this
hollow
Cylinder
we
fitted
a
wooden
Plug
,
like
one
of
those
described
in
the
foregoing
Experiment
,
save
that
it
was
not
quite
so
long
,
and
that
it
was
furnished
with
a
Rimme
or
Lip
,
which
was
purposely
made
of
a
considerable
breadth
,
that
it
might
afford
a
stable
Basis
to
the
Weight
that
should
lean
upon
it
.
And
then
taking
a
middle
siz'd
and
limber
Bladder
,
strongly
tyed
at
the
Neck
,
but
not
near
full
blown
,
we
press'd
it
by
the
help
of
the
Plug
into
the
Cylinder
to
make
it
the
better
accommodate
it self
to
the
figure
of
it
.
Then
taking
notice
by
an
inky
mark
how
much
of
the
Plug
was
extant
above
the
orifice
of
the
vessel
,
The
Weight
that
was
lifted
up
by
the
Bladder
in
the
Cylinder
4
inches
broad
,
was
75
pound
;
this
Weight
was
lifted
up
till
the
wooden
Plug
disclos'd
the
Mark
,
that
was
to
shew
the
height
,
at
which
the
Air
kept
the
said
Plug
before
it
was
comprest
:
disclos'd
it
I
say
visibly
at
the
5th
Exuction
,
and
at
the
7th
that
mark
was
⅛
,
or
rather
3/16
above
the
Edge
of
the
Cylinder
.
In
the
Gage
where
the
Mercury
in
the
open
Air
was
wont
to
stand
about
⅛
above
the
uppermost
Glass-mark
,
it
was
deprest
till
it
was
⅛
below
the
second
mark
.
When
the
Air
was
let
in
,
it
was
a
pretty
while
before
the
Weight
did
manifestly
begin
to
subside
;
the
Bladder
being
taken
out
,
and
the
place
it
had
possess'd
in
the
Cylinder
being
supply'd
with
a
Sleeve
,
or
some
such
thing
,
and
the
Weight
laid
again
upon
the
Plug
,
we
found
that
at
24
Exuctions
the
Mercury
was
deprest
to
the
lowest
Mark
of
the
Gage
;
and
it
was
the
34
or
35th
Exuction
before
the
Receiver
appear'd
to
be
so
exhausted
,
as
to
put
an
end
to
the
sinking
of
the
Mercury
,
which
was
then
above
⅛
beneath
the
lowest
mark
.
Your
Lordship
will
easily
believe
,
that
most
of
the
Spectators
of
such
Tryals
thought
it
somewhat
strange
to
see
a
small
quantity
of
Air
,
which
was
not
onely
uncomprest
in
the
Bladder
,
but
did
not
near
fill
it
,
(
and
left
it
very
soft
and
yielding
to
the
least
touch
,
)
lift
up
so
easily
by
its
bare
Spring
such
Great
Weights
as
indeavoured
to
oppress
it
.
But
this
not
being
any
thing
near
a
sufficient
Tryal
,
how
far
the
conjecture
or
Hypothesis
formerly
propos'd
will
hold
,
I
thought
fit
to
make
the
utmost
Tryals
the
tallest
Receivers
I
could
procure
would
admit
:
and
having
caus'd
leaden
weights
to
be
purposely
cast
flat
like
Cheeses
,
and
as
broad
as
we
could
conveniently
put
into
the
Receiver
,
that
by
the
advantage
of
this
shape
we
might
be
able
to
pile
up
the
more
of
them
,
without
much
danger
that
any
of
them
should
be
shaken
down
;
we
laid
divers
of
them
one
upon
another
,
and
then
the
upper
part
of
the
Receiver
growing
too
narrow
to
admit
more
of
them
,
we
added
a
less
broad
Weight
or
two
;
and
then
exhausting
the
Receiver
,
till
we
perceiv'd
by
the
Gage
that
the
Air
was
manifestly
withdrawn
,
we
found
(
as
near
as
we
could
measure
)
by
the
help
of
a
Mark
and
a
pair
of
Compasses
,
that
the
Plug
was
so
far
rais'd
,
as
that
t
was
concluded
,
that
the
Elevation
vvould
have
been
much
Greater
,
if
the
included
Air
,
being
put
upon
so
Great
a
Conatus
,
had
not
found
it
easier
to
produce
some
Leak
at
the
neck
of
the
Bladder
,
than
to
lift
up
so
Great
a
Weight
,
which
by
our
Reckoning
came
to
about
100
pound
of
16
ounces
to
the
pound
.
But
this
last
Experiment
,
for
want
of
some
requisite
accommodations
,
vve
vvere
hinder'd
from
repeating
and
promoting
;
though
the
above
mentioned
Hypothesis
made
me
presume
,
that
a
far
Greater
weight
might
this
way
have
been
rais'd
if
the
Bladder
had
been
stanch
,
and
the
Receiver
high
enough
.
I
need
not
tell
Your
Lordship
,
that
if
a
larger
Bladder
be
imploy'd
and
included
in
a
Brass
vessel
of
a
sufficiently
wide
Orifice
,
a
far
Greater
weight
may
be
lifted
up
by
the
Spring
of
the
internal
Air.
But
yet
it
will
not
be
amiss
to
give
Your
Lordship
on
this
occasion
this
Advertisement
,
which
may
be
fit
to
be
taken
notice
of
on
divers
others
:
That
care
must
be
had
not
to
make
Receivers
,
that
ought
to
be
well
emptied
,
too
large
,
and
especially
too
wide
at
the
Orifice
;
for
otherwayes
they
will
be
expos'd
to
so
great
a
Pressure
of
the
Atmosphere
,
that
they
need
be
of
an
extraordinary
strength
to
resist
it
;
and
even
Receivers
,
that
seem'd
thick
enough
proportionably
to
their
bulk
,
and
which
held
out
very
well
till
the
close
of
the
Operation
,
yet
when
they
came
to
be
very
diligently
exhausted
,
they
did
,
by
reason
of
the
wideness
of
their
Orifices
,
begin
to
crack
at
the
bottom
.
EXPERIMENT
XLIX
.
IN
one
of
my
publish'd
Experiments
[
*
](A28949-e12260-b)
*
viz.
the
XXXVI
.
I
long
since
told
Your
Lordship
,
that
when
I
endeavoured
,
by
the
help
of
a
seal'd
bubble
,
weigh'd
in
an
exhausted
Receiver
,
to
compare
the
Gravity
of
Air
and
Water
,
I
was
hinder'd
by
the
casual
breaking
of
the
Glass
from
compleating
the
Experiment
.
Wherefore
I
afterwards
thought
fit
to
repeat
the
Tryal
;
and
though
when
I
had
done
so
twice
or
thrice
,
having
given
away
the
large
Receiver
I
had
made
use
of
about
them
,
and
not
being
able
ever
since
to
procure
a
Good
one
,
that
was
capacious
enough
for
the
tender
Scales
I
thought
so
nice
an
Experiment
required
,
I
did
not
prosecute
that
Attempt
so
far
as
I
intended
;
yet
this
very
difficulty
I
met
with
to
procure
the
Requisites
of
making
the
Tryal
,
invites
me
to
subjoyn
the
two
following
Notes
,
which
I
find
among
my
loose
Papers
.
We
weigh'd
a
Bubble
in
the
Receiver
,
We
weighed
in
the
Receiver
a
Bubble
,
in
vacuo
27/32
of
a
Grain
:
the
Water
that
fill'd
it
weighed
720
¼
Grains
:
So
that
by
this
Experiment
the
proportion
of
the
weight
of
Air
to
Water
is
as
(
one
)
to
(
853
17/27.
)
The
Tryals
mentioned
in
these
Notes
,
though
they
were
too
few
for
me
to
acquiesce
in
,
yet
being
made
in
a
nevv
vvay
,
and
which
has
some
advantages
above
those
that
have
been
hitherto
imployed
to
weigh
the
Air
,
may
yet
serve
to
keep
us
from
the
contrary
.
Extremes
,
that
have
not
been
avoided
by
such
eminent
Mathematicians
as
Galileo
and
Ricciolus
;
the
former
of
which
makes
Water
to
be
but
about
400
times
as
heavy
the
Air
;
and
the
later
,
whose
conjecture
is
much
remoter
from
the
Truth
,
10000
times
heavier
.
But
it
is
so
desireable
a
thing
,
and
may
prove
of
such
importance
,
to
know
the
proportion
in
Weight
betwixt
Air
and
Water
,
that
I
shall
not
scruple
to
acquaint
Your
Lordship
with
an
attempt
or
two
that
I
made
to
discover
it
by
another
way
:
For
,
though
at
first
sight
this
Experiment
may
seem
to
be
the
same
with
one
publish'd
a
pretty
while
ago
in
the
learned
Schottus
his
Mechanica
Hydraulico
pneumatica
;
yet
Your
Lordship
will
easily
perceive
this
difference
between
them
:
That
,
whereas
the
industrious
Author
of
that
Experiment
contents
himself
to
shew
,
by
the
diminution
of
the
weight
of
a
Glass
,
when
the
Air
has
been
drawn
out
of
it
,
that
the
Air
,
before
t
was
drawn
out
,
was
not
devoid
of
Gravity
;
the
following
Tryal
does
not
onely
perform
the
same
thing
,
and
by
a
superadded
circumstance
confirm
the
Truth
to
be
thereby
prov'd
,
but
it
indeavours
also
to
shew
the
Proportion
in
Gravity
betwixt
the
Air
and
Water
.
The
Tryals
themselves
were
registred
among
my
Adversaria
as
follows
.
A
small
Receiver
being
exhausted
of
Air
by
the
Engine
,
and
counterpois'd
whilst
it
continued
so
;
the
Stop-cock
was
turn'd
,
and
the
Air
readmitted
,
which
made
it
weigh
36
Grains
more
than
it
did
before
:
and
to
prevent
Jealousies
,
we
caus'd
it
to
be
applied
the
second
time
to
the
Engine
,
by
which
the
Air
being
emptied
once
more
,
the
Glass
was
put
into
the
other
Scale
of
the
former
Ballance
,
and
so
counterpois'd
;
and
then
the
External
Air
being
readmitted
,
(
which
rush'd
in
as
formerly
with
a
whistling
noise
)
,
there
was
found
36
Grains
or
better
,
requisite
to
restore
the
Ballance
to
an
Aequilibrium
.
We
took
a
small
Glass
Receiver
fitted
with
a
Stopcock
,
and
having
exhausted
it
of
the
Air
,
and
counterpois'd
it
,
and
let
in
the
outward
Air
,
we
found
the
vveight
of
the
Vessel
to
be
increased
by
that
admission
36
Grains
.
This
done
,
we
took
the
Receiver
,
after
having
well
counterpois'd
it
,
out
of
the
Scale
;
and
having
apply'd
it
the
second
time
to
the
Engine
,
we
once
more
withdrew
the
Air
,
and
then
turning
the
Stop-cock
to
keep
out
the
external
Air
,
vve
took
care
that
none
of
the
Cement
,
imploy'd
to
joyn
it
to
the
Engine
,
should
stick
to
it
,
as
we
had
diligently
freed
it
from
adherent
Cement
before
we
last
apply'd
it
to
the
Engine
.
Then
weighing
it
again
,
we
found
it
to
weigh
either
35
or
36
Grains
(
but
rather
the
former
)
heavier
than
it
did
,
when
t
was
last
counterpois'd
in
the
same
Ballance
.
This
being
also
done
,
we
immers'd
the
Stop-cock
into
a
Bason
of
fair
Water
,
and
let
in
the
Liquor
,
that
we
might
find
how
much
Water
would
succeed
in
place
of
the
Air
vve
had
drawn
out
.
When
no
more
vvater
vvas
impell'd
in
,
vve
turned
the
Stop-cock
once
more
,
to
keep
it
from
falling
out
,
and
then
weighing
it
in
the
same
Scales
,
(
after
we
had
wip'd
the
Stop-cock
,
that
no
Water
might
stick
to
it
on
the
outside
,
)
we
found
the
water
(
without
computing
the
vessel
)
to
weigh
47
ounces
,
3
drachms
,
and
6
Grains
,
vvhich
divided
by
35
Grains
,
(
which
I
took
to
be
the
weight
of
the
Air
,
that
vvas
equal
in
Bulk
to
this
vvater
that
succeeded
it
,
)
the
Quotient
was
(
wanting
a
very
litle
)
650
Grains
,
for
the
proportion
of
the
vveight
between
Air
and
Water
of
the
same
bigness
,
at
the
time
when
the
Experiment
was
made
:
vvhich
circumstance
I
therefore
take
notice
of
,
because
the
Atmosphere
appear'd
by
the
Baroscope
(
wherein
the
Mercury
stood
then
at
29
inches
and
3/4
)
to
be
very
heavy
;
which
made
me
the
less
wonder
to
find
this
proportion
not
so
Great
,
as
at
other
times
I
had
observed
it
to
be
between
Water
and
Air
in
point
of
weight
:
though
I
suspected
,
that
because
this
odd
Experiment
cannot
be
nimbly
dispatched
,
some
litle
Air
may
have
got
in
at
the
Stop-cock
,
besides
the
Air
that
disclos'd
it self
in
numerous
bubbles
in
the
vvater
that
vvas
admitted
,
vvhere
though
it
lay
in
such
small
particles
as
not
to
be
discerned
before
;
yet
these
particles
,
by
this
opportunity
to
expand
themselves
,
extricated
themselves
from
the
vvater
,
and
by
getting
together
might
somewhat
resist
the
Ingress
of
more
;
vvhich
is
a
difficulty
,
vvhere
to
the
measuring
the
proportion
between
VVater
and
Air
in
a
heated
Eoliple
is
liable
.
But
the
Stealing
in
of
any
Air
,
before
the
vvater
vvas
let
in
,
is
mentioned
but
as
a
Suspicion
.
Your
Lordship
may
perhaps
think
it
somewhat
strange
,
that
I
should
present
You
Tryals
,
whose
Events
do
not
so
vvell
agree
together
,
as
perchance
You
expected
.
But
this
very
Disagreement
vvas
one
of
the
motives
that
induc'd
me
to
acquaint
You
vvith
them
:
for
all
those
compris'd
in
these
Experiments
being
made
faithfully
,
and
not
without
(
at
the
least
)
an
ordinary
diligence
,
as
they
seem
to
make
it
probable
,
that
one
may
without
any
Great
errour
estimate
the
proportion
of
our
English
Air
to
VVater
to
be
as
(
One
)
to
some
number
betwixt
600
and
1100
;
so
t
is
not
to
be
expected
,
that
the
Proportion
,
vvhatever
it
be
that
should
be
pitch'd
upon
,
should
be
accurate
and
stable
.
For
though
Learned
men
seem
to
have
hitherto
taken
it
for
granted
,
that
it
may
suffice
once
for
all
diligently
to
investigate
the
proportion
betwixt
those
two
Bodies
,
yet
,
not
onely
I
am
apt
to
believe
that
a
Determinate
quantity
of
Air
(
as
a
Pint
or
Quart
)
may
be
unequally
heavy
in
distant
Countreys
,
and
even
in
differing
places
of
the
same
Countrey
;
but
what
I
have
taken
notice
of
in
the
17th
of
the
printed
Experiments
,
and
afterwards
frequently
observ'd
of
the
Great
inequalities
of
the
vveight
of
the
Atmosphere
,
inclines
me
to
think
,
that
in
the
self
same
place
two
Experiments
may
be
made
with
the
same
Instruments
,
and
equal
diligence
,
and
yet
the
weights
of
the
Air
may
be
found
differing
enough
;
which
may
keep
Your
Lordship
from
much
wondering
,
that
in
the
36th
printed
Experiment
,
made
when
I
had
the
variations
of
the
Atmospheres
Gravity
in
my
Eye
,
I
found
the
Air
to
be
less
ponderous
in
reference
to
Water
,
than
in
these
later
Tryals
.
But
of
this
I
hope
I
shall
,
if
God
permit
,
make
further
Tryals
with
the
same
vessels
,
at
times
when
I
shall
perceive
by
the
Baroscope
,
that
the
Gravity
of
the
Atmosphere
is
very
Great
and
very
Small
.
And
I
wish
the
Curious
would
make
the
like
Tryals
in
other
Regions
.
I
do
not
forget
,
that
not
onely
the
School
philosophers
,
but
most
of
the
Moderns
deny
,
that
Air
hath
any
weight
in
Air
,
no
more
than
Water
in
Water
;
but
having
[
a
](A28949-e12480-b)
a
In
the
Hydrostatical
Paradoxes
.
elsewhere
declared
and
explained
my
sense
about
this
received
Opinion
,
I
shall
not
here
spend
any
of
the
litle
time
I
have
remaining
,
to
justifie
my
Dissent
;
for
which
Your
Lordship
may
find
sufficient
Grounds
in
the
newly
related
Experiments
,
especially
if
You
please
to
consider
,
that
though
the
Opinion
I
disallow
have
been
chiefly
and
generally
grounded
upon
some
Arguments
supposed
to
evince
,
that
vvater
has
no
vveight
in
vvater
,
I
have
[
b
](A28949-e12490-b)
b
In
an
Appendix
to
those
Paradoxes
.
elsewhere
shewn
those
Proofs
not
to
be
cogent
,
and
taught
a
Practical
way
of
weighting
vvater
in
vvater
with
a
pair
of
ordinary
Scales
.
[
c
](A28949-e12500-b)
c
This
method
was
omitted
in
the
English
Edition
of
the
newly
mentioned
Appendix
,
but
not
in
the
Latin
Version
.
EXPERIMENT
L.
About
the
disjoyning
of
two
Marbles
(
not
otherwise
to
be
pull'd
asunder
without
a
great
weight
)
by
withdrawing
the
pressure
of
the
Air
from
them
.
IN
our
formerly
publish'd
Experiments
about
the
Air
[
*
](A28949-e12560-b)
*
Experiment
the
XXXI
.
See
also
the
cause
of
this
Phaenomenon
discours'd
of
in
the
Authors
History
of
Fluidity
and
Firmness
.
,
I
did
,
if
I
misremember
not
,
acquaint
Your
Lordship
with
an
Attempt
I
had
made
to
make
a
couple
of
coherent
Marbles
fall
asunder
,
by
withdrawing
the
Air
from
them
;
but
though
I
then
esteem'd
that
their
Cohaesion
depended
upon
the
Pressure
of
the
Air
,
yet
not
being
at
that
time
furnish'd
with
all
the
accommodations
requisite
to
make
an
Experiment
not
easie
to
be
perform'd
succeed
,
I
thought
fit
,
when
I
had
afterwards
opportunity
,
to
prosecute
what
I
then
began
,
and
add
some
circumstances
that
I
could
not
then
make
Tryal
of
;
and
yet
whose
success
will
not
I
presume
be
unwelcome
,
since
it
supplies
us
with
no
less
than
matters
of
fact
;
whence
we
may
argue
,
that
this
Experiment
of
coherent
Marbles
(
which
not
onely
the
Aristotelian
Plenists
have
of
late
much
triumph'd
in
,
but
which
some
recent
Favourers
of
our
Hypothesis
have
declar'd
themselves
to
be
troubled
with
)
is
not
onely
reconcileable
to
our
Doctrine
,
but
capable
of
being
made
a
confirmation
of
it
;
notwithstanding
what
has
lately
been
publish'd
(
upon
the
supposition
of
a
case
,
which
at
first
Blush
may
seem
somewhat
of
kin
to
our
Experiment
,
)
by
a
very
learned
[
*
](A28949-e12610-b)
*
Dr.
H.
M.
in
the
2d
.
chap.
of
the
2d
.
Book
of
the
new
Edition
(
in
folio
)
of
his
Antidote
against
Atheism
.
Writer
,
to
whose
objection
against
our
Hypothesis
,
though
as
well
confidently
as
very
civilly
proposed
,
an
Answer
may
in
due
place
,
if
your
Lordship
desire
it
,
be
return'd
.
We
took
two
flat
round
Marbles
,
each
of
them
of
two
inches
and
about
3
quarters
in
Diameter
,
and
having
put
a
litle
Oyl
between
them
to
keep
out
the
Air
,
we
hung
at
a
Hook
fastned
to
the
Lowermost
a
Pound
weight
to
surmount
the
Cohaesion
,
which
the
tenacity
of
the
Oyl
and
the
imperfect
Exhaustion
of
the
Receiver
might
give
them
.
Then
having
suspended
them
in
the
cavity
of
a
Receiver
,
at
a
stick
that
lay
(
Horizontally
)
a
cross
it
;
when
the
Engine
was
fill'd
,
and
ready
to
work
,
we
shook
it
so
strongly
,
that
those
that
were
wont
to
manage
it
,
concluded
,
it
would
not
be
near
so
much
shaken
by
the
Operation
.
Then
beginning
to
pump
out
the
Air
,
we
observ'd
the
Marbles
to
continue
joyned
till
it
was
so
far
drawn
out
,
that
we
began
to
be
diffident
whether
they
would
separate
.
But
at
the
16th
Suck
,
upon
the
turning
of
the
Stop-cock
,
(
which
gave
the
Air
a
passage
out
of
the
Receiver
into
the
Pump
,
)
the
shaking
of
the
Engine
being
almost
,
if
not
quite
,
over
,
the
Marbles
spontaneously
fell
asunder
,
wanting
that
Pressure
of
the
Air
,
that
formerly
had
kept
them
together
:
which
Event
was
the
more
considerable
,
not
onely
because
they
hung
parallel
to
the
Horizon
,
but
adher'd
so
firmly
together
when
they
were
put
in
,
that
having
try'd
to
pull
them
asunder
,
and
thereby
observ'd
how
close
they
stuck
together
,
I
foretold
it
would
cost
a
good
deal
of
pains
so
far
to
withdraw
the
Air
,
as
to
make
them
separate
:
which
Conjecture
Your
Lordship
will
the
less
wonder
at
,
if
I
adde
,
that
a
weight
of
80
and
odd
pounds
,
fastned
to
the
lowermost
Marble
,
may
be
drawn
up
together
with
the
uppermost
,
by
vertue
of
the
firmness
of
their
Cohesion
.
NB.
This
is
not
the
onely
time
that
this
Experiment
succeeded
with
us
.
For
sometimes
,
when
they
were
not
so
closely
press'd
together
before
they
were
put
in
,
the
Disjunction
was
made
at
the
8th
Suck
,
or
sooner
,
and
we
seem'd
to
our selves
to
observe
,
that
when
we
hung
but
half
a
pound
weight
to
the
lower
Marble
,
it
requir'd
a
Greater
exhaustion
of
the
Receiver
to
separate
them
,
than
when
we
hung
the
whole
Pound
.
After
,
having
proceeded
thus
far
with
the
Instruments
we
then
had
,
meeting
with
an
Artificer
that
was
not
altogether
unskilful
,
we
directed
him
to
make
(
what
we
wanted
before
in
that
place
)
such
a
Brass-plate
to
serve
for
a
Cover
or
Cap
to
the
upper
orifice
of
Receivers
open
at
the
top
,
as
we
have
divers
times
had
occasion
to
mention
already
in
giving
accounts
of
some
of
the
foregoing
Tryals
:
by
the
help
of
which
Contrivance
we
prosecuted
the
newly
related
Experiment
much
further
than
we
could
do
before
,
as
may
appear
by
the
following
account
.
We
fasten'd
to
the
lower
most
of
the
two
Marbles
a
weight
of
a
very
few
ounces
,
(
for
I
remember
not
the
precise
number
,
)
and
having
cemented
the
capp'd
Receiver
with
the
Marbles
in
it
,
as
before
,
to
the
Pump
,
we
did
by
a
string
,
whereof
one
end
was
tied
to
the
bottom
of
this
Turning-key
,
and
the
other
to
the
uppermost
Marble
,
and
which
(
string
)
past
through
the
Crank
or
Hook
belonging
to
the
Brass-Cover
;
we
did
,
I
say
,
by
the
help
of
this
string
,
and
by
turning
round
the
Key
,
draw
up
the
superiour
Marble
,
and
by
reason
of
their
coherence
the
lowermost
also
,
together
with
the
weight
that
hung
at
it
:
by
which
means
being
sure
,
that
the
two
Marbles
stuck
close
together
,
we
began
to
pump
out
the
Air
that
kept
them
coherent
;
and
after
a
while
,
the
Air
being
pretty
well
withdrawn
,
the
Marbles
fell
asunder
.
But
we
having
so
order'd
the
matter
,
that
the
lowermost
could
fall
but
a
litle
way
beneath
the
other
,
we
were
able
by
inclining
and
shaking
the
Engine
to
place
them
one
upon
another
again
,
and
then
letting
in
the
Air
somewhat
hastily
,
that
by
its
Spring
it
might
press
them
hard
together
,
we
found
the
Expedient
to
succeed
so
well
,
that
we
were
not
onely
able
by
turning
the
abovementioned
Cylindrical
Key
,
to
make
the
uppermost
Marble
take
up
the
other
,
and
the
annexed
weight
;
but
we
were
fain
to
make
a
much
more
laborious
and
diligent
Exhaustion
of
the
Air
to
procure
the
disjunction
of
the
Marbles
this
second
time
,
than
was
necessary
to
do
it
at
the
first
.
And
for
further
prevention
of
the
Objections
or
Scruples
that
I
foresaw
some
Prepossessions
might
suggest
,
I
thought
fit
to
make
this
further
Tryal
,
that
when
the
Marbles
were
thus
asunder
,
and
the
Receiver
exhausted
,
we
did
,
before
we
let
in
the
Air
,
make
the
Marbles
fall
upon
one
another
as
before
;
but
the
litle
and
highly
expanded
Air
that
remained
in
the
Receiver
,
having
not
a
Spring
near
strong
enough
to
press
them
together
,
by
turning
the
Key
we
very
easily
rais'd
the
uppermost
Marble
alone
,
without
finding
it
to
stick
to
the
other
as
before
.
Whereupon
we
once
more
joyn'd
the
Marbles
together
,
and
then
letting
in
the
external
Air
,
we
found
them
afterwards
to
stick
so
close
,
that
I
could
not
without
inconvenience
strain
any
further
,
than
I
fruitlesly
did
,
to
pull
them
fairly
asunder
;
and
therefore
gave
them
to
one
that
was
stronger
than
I
,
to
try
,
whether
he
could
do
it
,
which
He
also
in
vain
attempted
to
perform
.
And
now
,
my
Lord
,
though
I
had
thoughts
of
adding
divers
other
Experiments
to
those
I
have
hitherto
entertained
You
with
;
yet
(
upon
a
review
)
finding
These
to
amount
already
to
fifty
,
I
think
it
not
amiss
to
make
a
Pause
at
so
convenient
a
Number
.
And
the
rather
,
because
an
odd
Quartainary
Distemper
,
that
I
slighted
so
long
,
as
to
give
it
time
to
take
Root
,
is
now
grown
so
troublesome
,
that
I
fear
it
may
have
too
much
influence
upon
my
Style
;
which
Apprehension
obliges
me
as
well
to
avoid
abusing
,
or
distressing
Your
Lordship's
Patience
,
as
to
allow
my self
some
seasonable
Refreshment
,
to
reserve
the
mention
of
the
design'd
Additions
till
they
can
with
less
trouble
to
us
both
be
presented
You
by
My
Dear
Lord
Your
Lordship's
most
humble
Servant
,
and
Affectionate
Uncle
,
ROBERT
BOYLE
.
Oxford
,
March
the
24.
1667.