MAGNETICALL
Aduertisements
.
CHAP.
I.
Of
the
magneticall
power
and
force
of
the
whole
Globe
of
the
Earth
.
COncerning
the
Magneticall
force
of
the
whole
body
of
the
Earth
,
I
haue
selected
these
experiments
to
proue
it
.
Take
any
peece
of
solid
earth
that
hath
some
toughnesse
to
hold
together
,
and
will
abide
the
fire
,
as
any
sort
of
clay
,
or
bricke
(
which
somtimes
was
clay
)
fashion
it
in
such
manner
that
it
bee
vniformely
extended
towards
both
ends
(
the
Ouall
or
long
figure
is
fittest
for
our
purpose
)
put
it
into
a
fire
of
charcoles
,
increasing
the
heat
by
little
and
little
,
and
at
the
length
with
often
blowing
,
make
it
throughly
as
red
hot
as
you
can
:
let
it
remaine
so
for
the
space
of
halfe
an
houre
,
or
more
,
that
thereby
all
superfluous
moisture
may
be
consumed
,
and
aduerse
qualities
separated
from
it
,
then
take
it
forth
,
and
let
it
coole
of
it selfe
,
being
first
set
North
and
South
,
with
either
end
answerable
to
the
variation
of
the
place
,
not
paralell
vnto
the
Horizon
,
but
eleuated
answerable
to
the
Latitude
as
nere
as
you
can
.
Certaine
it
is
that
this
peece
of
earth
thus
ordered
,
will
sensibly
shew
you
that
it
hath
true
Magneticall
vertue
.
But
here
before
I
proceed
any
farther
I
must
deliuer
vnto
you
a
necessary
obseruation
:
There
are
two
kindes
of
Attractions
(
as
they
are
commonly
called
)
the
one
Magneticall
,
the
other
Electricall
.
The
Magneticall
hath
alwaies
speciall
respect
vnto
the
North
&
South
points
of
the
Magnete
or
Magneticall
body
.
The
Electricall
body
hath
no
manner
of
respect
vnto
any
one
point
of
the
Electricall
body
,
more
than
another
:
And
by
this
difference
these
two
kinds
of
Attractions
are
easily
discerned
;
As
also
by
this
,
looke
what
end
of
the
Magneticall
needle
the
one
end
of
the
Magnet
doth
draw
,
the
other
will
chase
away
;
but
the
Electricall
body
draweth
alike
at
all
ends
.
And
thirdly
after
this
sort
,
lapp
this
Electricall
body
in
a
paper
and
it
will
draw
nothing
at
all
,
but
interposition
of
brasse
or
of
a
stone
wall
within
the
orbe
of
the
Magnets
vertue
,
doth
nothing
weaken
the
same
,
or
hinder
his
effect
towards
his
peculiar
obiect
.
Notwithstanding
(
to
speake
properly
)
Attraction
pertaineth
onely
to
Electricall
bodies
,
because
the
whole
attractiue
vertue
is
onely
in
the
Electricall
body
it selfe
,
and
nothing
at
all
in
the
thing
that
is
attracted
.
The
Attraction
(
commonly
so
called
)
of
the
Loadstone
is
rightly
to
be
termed
,
Concursion
,
Confluence
,
or
Coition
,
because
it
is
the
running
or
vigorous
meeting
together
of
two
Magneticall
bodies
hauing
a
mutuall
inclination
the
one
to
ioyne
with
the
other
,
or
by
any
other
name
,
bearing
like
sense
.
For
the
true
knowledge
thereof
,
being
but
lately
as
a
stranger
arriued
amongst
vs
,
common
vse
(
Quempenes
arbitrium
est
,
&
ius
&
normal
loquendi
.
)
hath
as
yet
scant
suted
it
,
with
a
conuenient
name
to
expresse
this
property
;
So
that
Magneticall
Concursion
is
neuer
but
betweene
two
bodies
,
such
as
both
of
them
are
Magneticall
;
As
of
one
Loadstone
with
another
,
or
of
a
Loadstone
with
yron
or
steele
,
or
yron
oare
if
it
be
prepared
,
or
betweene
two
peeces
of
yron
or
steele
that
are
reuiued
with
a
Loadstone
;
for
indeed
the
Loadstone
can
but
reuiue
,
and
multiply
Magneticall
force
in
a
body
that
naturally
hath
it
in
some
measure
before
:
but
cannot
infuse
it
into
any
thing
,
that
before
is
vtterly
voide
of
it
,
as
of
mettals
,
in
yron
or
steele
,
and
not
in
gold
,
siluer
,
brasse
,
&c.
Electrum
in
this
argument
is
named
that
which
is
either
Amber
in
substance
,
or
at
the
least
of
the
quality
,
and
that
Amber
,
being
rubbed
,
hath
,
to
take
vp
moats
,
feathers
,
strawes
,
sticks
,
and
other
small
things
.
The
which
property
is
also
in
ieate
,
brimstome
,
hard
waxe
,
(
if
it
be
smooth
)
and
in
infinite
other
things
both
naturall
and
compound
;
all
which
because
of
that
qualitie
in
this
argument
are
termed
Electricall
bodies
,
and
their
taking
vp
of
things
is
called
Electricall
attraction
,
hauing
onely
a
slender
resemblance
,
and
no
truth
of
the
Magneticall
qualitie
.
But
that
aboue-mentioned
peece
of
earth
,
prepared
in
such
sort
as
is
before
prescribed
,
will
by
Magneticall
concursion
shew
it selfe
to
be
a
true
Magneticall
body
.
For
the
one
end
of
the
Magneticall
needle
will
couet
towards
the
one
of
the
prepared
masse
,
and
flie
from
the
other
.
And
contrariwise
also
,
though
it
will
do
both
but
weakely
,
not
with
power
comparable
to
a
naturall
Loadstone
,
yet
as
truely
as
that
.
That
end
which
cooled
toward
the
South
,
will
draw
the
true
North
end
of
the
needle
,
and
that
end
which
cooled
toward
the
North
will
draw
the
true
South
end
of
the
needle
.
If
so
be
as
yet
you
will
haue
another
infallible
argument
,
doe
thus
:
Marke
what
end
draweth
the
North
end
of
the
needle
,
afterward
put
the
new
made
Magnet
into
the
fire
againe
,
and
when
it
hath
been
glowing
for
the
space
of
halfe
a
quarter
of
an
houre
,
take
it
out
and
coole
it
being
placed
with
that
marked
end
toward
the
North
,
most
assuredly
that
end
now
will
draw
the
South
end
of
the
needle
,
&
the
North
end
of
the
needle
will
shun
it
,
which
before
approached
vnto
it
.
The
reason
here
of
is
,
because
the
fire
hauing
abolished
all
the
former
Magneticall
qualitie
of
that
masse
wherewith
it
was
in
a
contrary
position
affected
in
the
former
cooling
,
now
leaueth
it
apt
and
fit
to
receiue
any
other
new
impression
:
which
presently
it
taketh
againe
either
regularly
,
if
in
the
cooling
it
be
placed
with
the
ends
to
the
North
and
South
,
or
(
if
it
be
placed
otherwise
)
confusedly
,
by
the
Magneticall
force
and
vertue
of
the
whole
body
of
the
earth
,
by
regular
and
confused
,
this
is
the
meaning
.
Take
any
lump
of
earth
,
or
any
brick-bat
ordered
in
this
sort
,
certaine
it
is
that
this
lumpe
of
earth
or
bricke-bat
hath
some
magneticall
vertue
therein
,
yet
so
feeble
and
weake
,
that
our
sence
cannot
discerne
it
,
because
of
the
vnfitnesse
of
the
forme
,
and
the
confused
dispersion
of
that
weake
force
,
through
the
whole
body
thereof
.
Then
suppose
you
will
bring
either
of
these
into
an
extended
ovall
forme
,
which
is
most
apt
(
as
before
I
said
)
for
any
body
magneticall
to
shew
his
force
,
yet
this
will
helpe
it
nothing
at
all
of
it selfe
,
as
you
may
easily
make
experience
in
euery
Loadstone
.
For
if
you
take
a
loadstone
of
a
confused
forme
,
it
is
not
inough
to
bring
it
into
a
conuenient
ovall
,
except
with
diligence
you
reserue
the
points
of
the
North
and
South
in
the
two
ends
thereof
,
for
if
you
leaue
the
points
in
the
sides
you
marre
it
with
this
ovall
forme
.
For
the
stone
will
not
lightly
be
of
one
quarter
of
the
force
,
it
was
ofbefore
;
For
the
ovall
forme
giueth
it
no
vertue
,
but
is
the
fittest
for
it
to
shew
the
vttermost
of
that
strength
,
which
of
it selfe
it
had
before
,
if
you
obserue
the
due
points
,
and
not
otherwise
.
But
in
this
earth
and
bricke
it
is
not
possible
to
finde
the
due
points
in
such
sort
as
you
may
in
a
Loadstone
,
because
of
the
weaknesse
of
the
magneticall
force
therein
contained
.
And
therefore
you
cannot
bring
that
into
a
regular
ovall
forme
,
to
haue
the
due
points
in
the
very
ends
.
But
if
you
first
make
it
into
an
ovall
forme
,
and
by
the
fire
take
away
the
confused
magneticall
force
,
and
all
other
peruerse
qualities
thereof
,
that
being
by
nature
a
magneticall
body
in
his
cooling
before
specified
,
receiueth
presently
by
that
vnresistable
power
of
the
earth
,
his
magneticall
vertue
,
according
vnto
that
forme
,
and
will
regularly
haue
his
due
points
precisely
in
the
ends
,
without
any
confusion
.
Iohannes
Baptista-Porta
Neapolitanus
,
writeth
that
hee
did
make
triall
of
the
way
that
Paracelsus
hath
set
downe
for
to
increase
the
vertue
of
a
magnet
,
namely
to
heate
him
red
hot
in
the
fire
,
and
to
quench
him
in
the
oyle
of
Crocus
Martis
:
And
Baptista
Porta
saith
,
that
hee
found
it
a
detestable
falshood
.
For
saith
hee
,
he
is
so
farre
from
increasing
his
vertue
,
as
that
(
being
once
red
hot
)
he
looseth
all
his
own
,
past
all
recouery
.
But
for
all
this
that
hee
saith
,
I
doubt
whether
Paracelsus
be
iustly
reprooued
or
not
,
for
by
mine
owne
experience
I
know
that
the
heating
of
a
Loadstone
vntill
he
be
red
hotte
doth
weaken
a
loadstone
,
but
taketh
not
away
all
his
force
,
and
in
my
triall
here
of
I
found
a
very
manifest
proofe
of
the
magnetisme
of
the
earth
,
which
I
thought
necessary
for
to
insert
in
this
place
.
I
haue
made
this
triall
of
Fragments
of
magnets
of
diuers
kindes
,
and
also
of
diuers
kindes
of
Iron
Mines
which
are
next
in
degree
vnto
magnets
,
namely
after
this
sort
.
Heate
him
in
the
fire
by
little
and
little
(
for
feare
of
breaking
)
vntill
he
be
red
hotte
,
then
take
him
out
and
let
him
coole
,
then
marke
(
with
chalke
or
what
you
please
)
those
parts
that
respect
the
North
and
South
and
you
shall
finde
those
marked
places
,
the
North
,
and
South
Poles
of
the
Magnet
:
put
him
into
the
fire
againe
,
vntill
he
be
red
hotte
,
and
coole
him
contrarily
,
and
you
shall
haue
the
contrary
effect
.
Therefore
if
Baptista
Porta
did
make
his
triall
with
a
Loadstone
very
long
in
forme
,
and
chaunced
(
for
Master
D.
Gilberts
mistery
of
the
Earths
magnetisme
,
was
not
then
reuealed
)
for
to
coole
him
in
his
oyle
of
Crocus
Martis
with
his
ends
East
and
West
,
the
axis
of
the
stone
being
then
ouerth
wart
in
the
middle
,
it
were
no
maruell
if
he
found
no
force
in
the
ends
.
And
I
do
not
thinke
it
improbable
,
but
that
Paracelsus
way
may
doe
some
good
rightly
vsed
.
Doctour
Gilbert
writech
that
some
Iron
mine
,
will
affect
a
magneticall
needle
,
as
it
is
of
it selfe
,
being
vnprepared
by
fire
:
but
as
yet
I
neuer
could
finde
any
such
,
but
this
I
haue
often
tried
,
that
it
being
of
no
manner
of
magneticall
vertue
of
it selfe
no
more
then
a
flintstone
vnprepared
by
fire
,
being
made
red
hott
,
and
cooled
,
is
presently
impregnated
with
very
apparant
magneticall
vertue
,
according
to
the
scituation
that
hee
is
cooled
in
,
and
although
you
heate
and
coole
him
often
,
and
diuers
waies
,
he
will
still
keepe
his
vertue
,
according
to
the
scituations
,
of
his
cooling
.
And
some
Iron
Mines
I
haue
found
,
which
being
but
in
this
sort
prepared
haue
had
as
strong
force
as
some
naturall
magnets
haue
had
.
It
is
the
goodnesse
of
the
Loadstone
ioyned
with
a
fit
forme
that
will
shew
great
force
.
For
as
a
very
good
forme
with
base
substance
can
doe
but
very
litle
,
so
the
substance
of
the
Loadstone
bee
it
neuer
so
excellent
,
except
it
haue
some
conuenient
forme
,
is
not
auaileable
.
For
example
,
an
excellent
loadstone
of
a
pound
waight
and
of
a
good
fashion
,
being
vsed
artificially
,
may
take
vp
foure
pounds
of
Iron
;
beate
it
into
small
pouder
,
and
it
shall
bee
of
no
force
to
take
vp
one
ounce
of
Iron
;
yea
I
am
very
well
assured
that
halfe
an
ounce
of
a
Loadstone
of
good
fashion
,
and
of
like
vertue
will
take
vp
more
then
that
pound
will
doe
being
beaten
into
powder
.
Whence
,
(
to
adde
this
by
the
way
)
it
appeareth
manifestly
,
that
it
is
a
great
error
of
those
Phisitions
and
Surgeons
,
which
to
remedy
ruptures
,
doe
prescribe
vnto
their
Patients
to
take
the
pouder
of
a
Loadstone
inwardly
,
and
the
small
filing
of
iron
mingled
in
some
plaister
outwardly
:
supposing
that
herein
the
magneticall
drawing
should
doe
great
wonders
.
Whereas
they
consider
not
that
the
stone
being
dissolued
into
powder
,
euery
little
particle
of
the
dust
hath
two
points
contrarie
,
the
one
drawing
to
,
the
other
repelling
and
putting
from
:
and
so
being
thus
confounded
by
a
contrarie
working
doth
much
more
harme
,
then
good
with
his
magneticall
quality
.
As
for
the
astringent
,
and
drying
properties
of
the
Loadstone
I
leaue
them
to
the
diligent
obseruation
and
iudgment
of
the
skilfull
in
phisicke
.
But
to
returne
to
our
purpose
,
and
to
alledge
this
also
,
besides
the
former
manifest
proofe
,
if
the
earth
were
not
by
nature
a
magneticall
body
,
the
afore
mentioned
peice
of
earth
could
not
receiue
from
a
Loadstone
any
magneticall
power
:
But
most
certaine
it
is
,
and
by
many
vndoubted
experiments
confirmed
,
that
it
will
euidently
receiue
magneticall
power
,
from
a
Loadstone
:
therefore
it
is
manifest
that
the
earth
is
by
nature
a
magneticall
body
.
Furthermore
,
as
among
all
the
mettals
iron
doth
incomparably
more
resemble
the
earth
in
substance
then
any
other
doth
,
it
likewise
doth
more
participate
with
the
earth
in
quality
,
and
principally
in
the
magneticall
peculiar
property
hereof
,
as
notorious
experience
declareth
,
yea
euery
peice
of
iron
Oare
,
being
naturally
(
as
D.
Gilbert
sheweth
)
a
magnet
,
although
of
feeble
force
,
and
all
magnets
being
a
kinde
of
iron
Oare
,
is
the
very
cause
,
that
onely
iron
or
steele
,
and
no
other
mettall
is
capable
of
that
vertue
,
namely
to
haue
that
reuiued
,
and
multiplied
by
the
vicinity
of
a
magnet
,
which
at
the
first
in
some
measure
,
was
originall
in
it selfe
,
as
it
is
aforesaid
;
It
is
also
well
knowne
,
that
the
magnet
is
a
Stone
most
commonly
of
inuincible
hardnesse
,
nothing
inferiour
to
any
iron
or
steele
of
the
excellentest
sort
,
notwithstanding
sometimes
wee
see
of
them
that
are
nothing
,
but
a
dry
lumpe
of
earth
,
and
yet
of
those
also
some
stronger
in
vertue
,
then
diuers
of
the
hard
stony
ones
are
:
Which
earthly
magnets
if
a
man
assay
to
bring
it
into
a
fashion
by
grinding
on
a
grinding
stone
(
according
to
the
common
vse
)
they
will
consume
into
very
mudde
in
the
water
.
Now
(
to
drawe
towards
an
end
of
this
matter
)
albeit
the
magneticall
vertue
be
most
eminent
in
the
magnet
,
as
in
the
precise
and
perfect
subiect
thereof
:
yet
is
the
selfe
same
quality
,
in
a
meaner
degree
,
euidently
to
be
discerned
in
euery
peice
of
earth
,
prepared
and
ordered
(
as
is
aforesaid
)
yea
although
it
be
not
cooled
with
his
ends
North
and
South
,
that
it
may
take
his
magneticall
force
from
the
vertue
of
the
earth
,
for
if
you
coole
it
with
his
ends
but
East
and
West
and
set
two
Loadstones
in
the
cooling
,
the
one
at
one
end
and
the
other
at
the
other
end
,
it
will
receiue
a
sensible
and
apparant
magneticall
vertue
according
to
those
points
of
the
Loadstone
that
were
applied
vnto
it
,
namely
that
end
which
was
next
the
South
point
of
the
Loadstone
will
haue
a
North
properly
,
and
that
end
that
was
next
the
North
point
,
will
haue
a
South
property
:
yea
if
you
set
the
North
part
of
two
loadstones
vnto
each
end
,
both
ends
of
this
new
made
magnet
will
haue
a
South
property
;
And
contrariwise
if
you
apply
the
South
ends
of
two
magnets
,
both
his
ends
will
haue
a
North
property
;
And
those
properties
before
mentioned
will
shew
themselues
to
be
magneticall
,
because
whether
end
of
this
new
magnet
draweth
any
one
end
of
a
magneticall
needle
,
the
same
will
chase
away
the
other
:
which
is
proper
only
vnto
magnets
,
and
magnetical
bodies
.
After
the
like
sort
,
only
by
application
of
two
strong
loadstones
by
the
space
of
24.
houres
you
may
alter
the
points
of
any
base
loadstone
,
which
you
would
,
and
make
them
both
North
or
South
as
you
please
:
so
that
the
loadstone
which
you
would
alter
be
but
base
in
qualitie
,
and
not
great
in
substance
,
and
that
the
other
be
of
a
reasonable
bignes
,
and
good
strength
.
And
this
vertue
by
such
application
of
two
loadstones
I
haue
often
found
effectuall
in
new
bricke
lately
taken
from
the
kill
without
any
farther
putting
into
the
fire
at
all
;
And
although
it
be
against
the
nature
of
a
loadstone
to
haue
both
his
ends
naturally
of
one
vertue
,
that
is
to
say
,
both
of
them
of
a
North
property
,
or
both
of
them
of
a
South
property
:
yet
here
it
is
to
be
vnderstood
,
that
it
is
the
forcible
violence
of
the
strong
ones
,
being
applied
iointly
vnto
each
end
of
the
weake
,
that
doe
chase
the
contrarie
property
of
the
weake
one
into
the
middle
thereof
:
And
therefore
if
you
diuide
this
weak
one
in
the
middle
,
then
both
those
ends
,
which
being
ioyned
together
were
the
middle
,
(
where
no
loadstone
can
shew
any
vertue
)
being
now
disioyned
,
and
become
ends
,
will
presently
shew
a
contrary
property
(
according
vnto
magneticall
nature
)
vnto
the
other
two
ends
.
CHAP.
II.
The
ambiguity
of
the
North
and
South
ends
of
Magnets
and
Magneticall
bodies
explained
,
and
Doctor
Gilbert
therein
defended
.
THere
is
not
any
one
errour
that
breedeth
a
greater
confusion
in
magneticall
knowledge
,
then
the
mistaking
of
the
right
vnderstanding
of
the
true
North
and
South
ends
,
aswell
in
magnets
themselues
,
as
also
in
magneticall
bodies
,
who
soeuer
therefore
that
will
take
a
little
paines
in
the
beginning
for
to
vnderstand
this
well
,
shall
free
himselfe
from
many
intricate
difficulties
in
this
argument
,
which
otherwise
must
needes
befall
him
;
wherein
some
hauing
limed
themselues
,
haue
fallen
into
many
errors
,
euery
one
still
begetting
another
worse
then
himselfe
.
All
those
which
did
write
before
Doctor
Gilbert
did
name
that
end
of
a
magnet
which
being
placed
in
a
wooden
dish
,
and
set
to
swimme
in
water
,
would
turne
and
settle
it selfe
towards
the
North
,
the
North
end
of
the
magnet
;
and
the
other
the
South
end
.
And
euen
so
did
they
of
all
Dial-needles
,
Compasses
and
magneticall
bodies
.
But
Doctour
Gilbert
,
not
for
any
new-fangled
innouation
,
or
selfe-conceit
,
but
vpon
good
reason
and
firme
demonstration
auoucheth
and
prooueth
the
contrarie
,
and
clearely
sheweth
,
that
the
former
vulgar
assertion
seriously
defended
,
tendeth
vnto
the
ouerthrow
of
all
magneticall
Philosophie
,
by
vndermining
(
as
it
were
)
the
whole
frame
thereof
;
and
yet
in
common
speech
the
old
rule
may
hold
,
Loquendum
cum
vulgo
sentiendum
cum
sapientibus
.
For
it
would
seeme
a
strange
speech
vnto
a
Marriner
to
tell
him
that
his
Flower
de
luce
were
become
the
South
point
of
his
compasse
,
and
yet
this
assertion
is
most
true
,
and
certaine
that
it
is
the
North
end
of
euery
magnet
and
magneticall
body
,
that
being
placed
in
a
thinne
wodden
dish
in
water
,
or
any
magneticall
needle
vpon
his
pinne
,
which
setteth
it selfe
and
pointeth
vnto
the
South
,
and
it
is
the
South
end
which
pointeth
vnto
the
North.
For
proofe
hereof
,
take
these
wordes
of
North
and
South
in
whether
of
the
two
former
significations
you
please
,
and
make
triall
thereof
in
any
two
magnets
,
or
any
two
magneticall
bodies
,
so
placed
that
they
may
freely
turne
according
vnto
their
natures
,
and
you
shall
alwaies
see
a
naturall
inclination
of
the
contrary
ends
of
the
one
vnto
the
contrary
ends
of
the
other
,
as
of
the
North
end
of
the
one
vnto
the
South
end
of
the
other
,
and
reciprocated
of
the
South
of
the
one
to
the
North
of
the
other
;
But
the
ends
in
the
one
and
the
other
will
alwaies
flie
from
those
of
like
denomination
,
as
the
North
end
of
the
one
from
the
North
end
of
the
other
,
and
the
South
end
of
the
one
from
the
South
end
of
the
other
.
For
as
much
then
as
all
magnets
themselues
,
and
all
magneticall
bodies
(
being
so
placed
as
they
may
haue
their
free
motion
)
compose
themselues
magnetically
towards
the
Poles
of
the
earth
,
it
must
needs
be
that
it
is
the
true
naturall
South
end
of
the
Magnet
or
Magneticall
needle
,
that
pointeth
towards
the
North
of
the
Earth
:
and
it
is
the
true
naturall
North
end
of
the
Magnet
or
Magneticall
needle
that
pointeth
towards
the
South
of
the
Earth
,
because
the
contrary
ends
doe
affect
one
an
other
,
and
each
of
them
doe
naturally
flie
,
the
one
end
of
the
one
,
from
that
end
of
the
other
,
which
is
of
like
denomination
vnto
it selfe
:
for
example
,
In
this
following
Diagram
of
the
whole
Magnet
,
E.
A
,
is
supposed
to
note
the
true
naturall
North
end
thereof
,
and
B.
the
South
end
.
This
Magnet
being
placed
in
a
woodden
dish
,
swimming
in
water
,
freely
must
,
and
will
,
of
Magneticall
necessitie
,
with
his
true
North
end
,
A.
settle
himself
so
,
that
A.
must
point
towards
the
South
of
the
Earth
.
And
the
South
end
,
B.
towards
the
North
of
the
Earth
:
Because
all
Magnets
and
all
Magneticall
bodies
,
do
naturally
affect
,
the
one
the
contrary
end
of
the
other
,
and
doe
auoide
and
flie
from
their
ends
of
like
denomination
.
Now
for
a
further
consideration
of
these
properties
suppose
that
you
will
cut
of
a
peece
of
this
Magnet
meridionally
,
viz.
C.
D
:
manifest
experience
will
shew
,
that
C
,
which
did
in
nature
participate
with
A.
in
the
entire
Magnet
,
E
:
(
as
being
both
of
the
true
North
part
thereof
)
now
being
separated
,
will
not
abide
it
.
In
like
manner
D
,
of
the
other
end
of
the
little
one
,
will
not
abide
,
B
:
of
the
great
one
,
with
whom
being
entire
in
nature
he
did
participate
,
as
being
both
true
Southerly
parts
of
the
entire
Magnet
,
E
:
And
that
because
the
ends
of
like
denomination
of
any
two
Magnets
,
doe
naturally
flie
the
one
from
the
other
.
CHAP.
III.
Certaine
generall
obseruations
of
the
nature
and
properties
of
the
Loadstone
.
LOadstones
of
diuers
and
sundry
parts
of
the
world
as
of
Norway
,
Elva
,
Bengala
,
&c.
haue
one
and
the
selfe-same
property
directiue
,
I
meane
of
shewing
the
North
and
South
,
and
also
the
selfe-same
points
respectiue
declining
or
dipping
vnder
the
Horizon
.
They
doe
likewise
agree
in
their
variations
,
and
each
one
will
draw
yron
,
and
likewise
one
another
.
Euery
Loadstone
,
of
what
forme
soeuer
he
be
,
hath
either
actually
or
potentially
two
points
,
the
one
Northern
,
the
other
Southerne
.
Actually
,
if
either
by
casualty
(
if
it
so
fall
out
)
or
by
industry
the
stone
be
so
fashioned
,
that
those
two
opposite
points
be
eminent
or
perspicuous
therein
:
Potentially
,
if
that
either
the
stone
be
flat
and
but
thin
in
the
dimension
of
North
and
South
though
broad
otherwise
,
for
so
shall
the
vertue
of
the
stone
be
dispersed
to
the
extreame
parts
thereof
,
in
the
edges
round
about
;
or
if
it
haue
the
two
opposite
points
in
any
concauitie
,
then
will
the
stone
shew
in
the
eminent
border
or
edge
of
that
concauitie
onely
a
confused
dull
force
,
and
in
the
concauitie
it selfe
very
little
or
nothing
at
all
.
That
stone
is
well
proportioned
for
touching
which
resembleth
an
Ouall
forme
,
and
hath
his
due
points
in
his
ends
,
and
is
voide
of
any
bunch
or
concauitie
.
For
the
generall
forme
of
a
stone
being
good
,
euery
concauitie
is
a
diminishing
of
his
force
,
and
euery
bunch
is
but
a
superfluous
burden
;
Insomuch
that
my selfe
haue
made
experience
of
a
stone
that
of
substance
was
very
good
,
and
of
weight
was
vpon
a
three
and
twenty
ounces
,
but
of
a
disordered
forme
,
I
therefore
tooke
away
twelue
ounces
from
him
,
and
yet
diminished
not
one
iote
of
his
force
.
And
this
did
I
in
a
stone
that
was
all
of
like
substance
.
But
if
it
be
one
that
is
intermingled
of
diuers
substances
(
as
many
such
there
are
and
those
easily
discerned
by
their
colour
)
you
may
somtimes
take
away
three
quarters
and
more
of
his
substance
without
diminishing
any
thing
at
all
of
his
vertue
.
For
colours
,
most
commonly
the
Iron-like
is
best
:
very
blacke
or
whitish
seldome
proues
good
;
gray
,
indifferent
;
the
more
white
in
any
stone
,
so
much
the
worse
.
There
are
certaine
that
are
of
an
yron
colour
,
mingled
with
red
,
of
which
some
bee
very
good
,
some
but
indifferent
.
By
three
waies
you
may
proue
whether
a
Magnet
be
good
or
not
;
the
one
is
,
by
taking
vp
yron
with
the
bare
stone
:
The
other
by
giuing
more
or
lesse
vertue
vnto
a
knife
,
or
any
such
thing
to
lift
yron
:
The
third
if
it
will
with
good
strength
moue
a
Magneticall
needle
a
pretty
good
distance
of
,
and
readily
alter
the
ends
of
the
needle
without
touching
of
them
,
making
the
North
South
,
and
the
South
North
:
The
two
latter
of
these
doe
neuer
faile
,
but
the
first
doth
diuers
times
.
And
very
certaine
it
is
,
that
whatsoeuer
stone
doth
most
strongly
impart
his
force
vnto
a
knife
,
or
moue
a
needle
with
quicknes
,
the
power
of
lifting
vp
yron
in
such
a
one
,
will
mightily
be
increased
with
a
Cap.
For
this
is
generally
the
nature
of
all
Magnets
,
that
if
there
be
2.
of
different
quantities
,
and
equall
strength
in
lifting
vp
yron
,
the
greater
will
giue
the
stronger
touch
,
and
moue
a
Magneticall
needle
farther
of
,
although
the
lesser
will
take
vp
as
much
yron
,
or
somewhat
more
,
than
the
greater
.
And
againe
suppose
there
be
a
Magnet
of
a
pound
weight
,
that
being
fitly
armed
,
will
take
vp
foure
pounds
of
yron
,
and
not
aboue
,
if
you
diuide
him
into
very
small
peeces
,
you
shall
finde
of
them
being
orderly
vsed
that
will
lift
vp
20
times
,
yea
40
times
his
owne
weight
and
a
great
deale
more
,
if
they
be
made
very
small
,
as
of
three
or
foure
graines
weight
;
And
yet
where
the
great
one
will
giue
a
touch
vnto
a
knife
for
to
take
vp
foure
ounces
of
yron
,
and
will
moue
a
Magneticall
needle
three
foote
of
;
this
little
one
will
not
giue
a
touch
vnto
a
knife
to
take
vp
a
needle
,
nor
moue
a
Magneticall
needle
foure
inches
of
;
that
as
a
Magnet
is
diminished
in
substance
(
I
meane
a
Magnet
of
a
regular
forme
)
so
doth
he
loose
in
his
vertue
of
touching
,
and
increaseth
for
his
small
quantitie
in
lifting
of
yron
,
whereby
it
is
manifest
that
these
two
properties
goe
not
alwaies
ioyntly
together
in
the
same
proportion
and
degree
.
And
here
hence
it
is
,
that
many
seeing
little
Magnets
artificially
set
in
rings
for
to
take
vp
(
for
their
quantitie
)
a
great
peece
of
yron
,
doe
wrongfully
imagine
that
the
great
one
(
whose
particles
they
are
)
or
any
other
great
one
,
should
doe
the
like
,
namely
to
take
vp
so
many
times
their
owne
weights
.
Also
very
often
it
is
seene
,
that
Magnets
being
of
like
forme
and
weight
,
but
of
diuers
kinds
,
the
one
will
take
vp
more
yron
of
himselfe
without
the
capp
,
and
yet
the
other
giue
a
farre
stronger
touch
;
but
then
,
if
you
doe
fit
both
of
them
accordingly
with
caps
,
he
which
gaue
the
stronger
touch
,
will
take
vp
more
yron
than
the
other
.
The
principall
force
of
the
Loadstone
well
proportioned
,
passeth
in
a
direct
line
,
from
the
middle
of
his
substance
,
being
(
as
it
were
)
a
Center
,
through
his
two
ends
or
points
,
which
are
the
imaginarie
lines
of
his
chiefest
force
,
from
which
Center
,
there
issue
infinite
others
also
through
all
parts
of
the
Superficies
of
the
stone
,
on
either
side
,
betweene
the
two
extreame
points
and
the
middle
,
all
which
on
either
side
of
the
middle
,
being
of
one
nature
and
property
in
respect
of
their
touch
are
exceedingly
different
in
strength
.
For
that
still
waxeth
lesse
and
lesse
,
as
it
approacheth
continually
nearer
and
nearer
the
middle
,
where
at
length
in
the
middle
,
betweene
the
two
ends
,
it
vtterly
fainteth
and
commeth
to
nothing
.
The
Loadstone
communicateth
his
property
to
the
yron
or
steele
that
is
touched
with
it
,
so
farre
forth
,
as
the
yron
,
or
steele
,
which
is
touched
,
hath
habilitie
to
receiue
,
and
so
that
good
skill
in
the
touching
be
obserued
,
steele
is
farre
better
than
yron
,
and
receiueth
a
farre
stronger
touch
,
and
much
more
effectuall
.
The
purer
steele
,
so
much
the
better
;
and
if
it
bee
yron
,
the
purer
likewise
,
the
better
,
alwaies
regarding
that
both
of
them
be
very
smooth
,
and
cleane
,
and
haue
their
due
temper
.
The
principall
property
in
common
vse
is
the
shewing
of
North
and
South
in
the
Horizon
,
with
the
appendants
therevnto
belonging
,
which
is
much
more
apparant
,
more
strong
,
and
more
commodious
in
the
iron
and
steele
,
that
is
touched
,
than
it
is
in
the
stone
it selfe
,
because
the
substance
of
them
may
be
filed
and
cut
away
,
and
drawne
into
any
forme
,
that
we
like
or
list
our selues
,
which
the
substance
of
the
stone
will
not
permit
.
The
Magnet
is
of
such
nature
,
that
euery
peece
broken
of
and
separated
from
the
whole
,
hath
all
the
properties
of
the
whole
,
the
same
seuerall
points
of
North
and
South
,
and
habilitie
also
for
the
touch
,
like
in
kinde
,
though
not
of
equall
power
,
according
to
the
quantitie
and
proportion
of
the
peece
,
and
the
part
of
the
stone
that
it
is
taken
from
,
and
this
propertie
in
a
meaner
sort
hath
the
touched
needle
and
wyar
of
a
Compasse
also
.
CHAP.
IIII.
By
what
meanes
the
chiefe
points
of
any
Magnet
of
what
forme
soeuer
may
easily
be
found
out
.
MAke
a
respectiue
or
declinatorie
needle
,
of
an
inch
or
thereabouts
in
length
and
giuing
him
his
touch
,
fasten
him
by
his
Axis
vpon
a
little
forked
sticke
,
or
any
such
thing
,
that
the
needle
may
haue
free
scope
,
then
offer
the
stone
neere
the
needle
,
turning
it
round
about
,
and
immediately
you
shall
see
the
North
of
the
needle
(
as
it
is
as
yet
commonly
called
,
because
it
pointeth
vnto
the
North
)
point
directly
vnto
the
true
North
end
of
the
stone
as
soon
as
it
commeth
neere
vnto
it
,
and
as
you
turne
away
the
end
of
the
stone
the
needle
will
point
still
somewhat
towards
it
,
till
the
South
end
of
the
stone
approacheth
,
for
then
will
the
needle
wheele
about
vpon
his
Axis
,
and
point
directly
with
his
South
,
and
to
the
true
South
of
the
stone
.
But
if
you
hold
the
needle
neere
the
stone
,
in
such
sort
that
it
cannot
turne
about
at
liberty
then
the
force
of
the
stone
may
soone
change
the
properties
of
the
ends
of
the
needle
,
that
the
one
point
which
was
North
shall
become
South
,
and
that
the
other
which
was
South
shall
become
North
,
yet
the
thing
it selfe
is
easily
discerned
:
For
the
Northerly
end
will
alwaies
hang
lower
.
And
wheresoeuer
the
needle
,
being
held
neerer
vnto
the
stone
doth
stand
parrallell
vnto
it
not
inclining
with
either
end
,
towards
the
stone
there
directly
,
vnder
the
middle
of
the
needle
,
the
North
and
South
properties
of
the
stone
doe
diuide
and
part
themselues
.
This
matter
is
much
better
performed
,
with
a
smal
narrow
loadstone
of
halfe
an
inch
(
more
or
lesse
)
in
length
,
hauing
in
the
ends
his
due
points
of
North
and
South
and
wrought
ouer
with
silke
of
two
colours
from
the
midle
to
each
end
;
as
for
example
yellow
and
white
;
That
part
which
pointeth
to
the
North
let
it
be
wrought
ouer
with
white
,
and
the
other
with
yellow
.
Then
if
you
hang
that
in
the
midle
by
a
fine
silke
thread
,
and
apply
it
vnto
any
other
loadstone
,
the
South
end
of
the
one
will
readily
finde
out
the
North
end
of
the
other
;
and
contrariwise
.
In
like
manner
,
with
this
magneticall
instrument
you
may
see
two
pretty
conclusions
.
The
one
if
you
touch
a
knife
with
the
end
of
a
forcible
loadstone
,
whether
it
be
North
or
South
,
and
hang
this
wrought
one
by
a
silke
thread
in
the
midle
,
that
it
may
hang
freely
,
the
one
end
will
craue
towardes
the
point
of
the
knife
,
and
the
other
will
not
abide
it
.
The
other
is
,
if
you
hang
it
end-long
,
with
the
true
North
end
right
ouer
the
North
end
of
a
forcible
loadstone
or
with
the
South
end
ouer
the
South
end
of
the
other
,
you
shall
see
that
it
will
in
no
wise
(
being
let
downe
)
come
vnto
the
North
point
of
that
loadstone
,
but
will
(
contrary
to
philosophicall
principles
that
heauie
things
should
tend
directly
downewards
)
by
the
meanes
of
the
silke
thread
,
swimme
or
wheele
about
the
end
of
the
loadstone
in
the
aire
:
yea
and
lift
it selfe
somewhat
vpward
,
rather
then
perpendicularly
light
downe
vpon
it
,
yea
this
it
will
do
although
you
place
a
plate
of
siluer
,
lattin
,
or
any
such
thing
,
betweene
the
stone
and
it selfe
.
The
second
way
.
Thread
a
common
sowing
needle
,
and
touch
the
point
of
it
with
the
North
end
of
any
loadstone
,
then
offer
it
vnto
that
stone
whose
points
you
would
find
out
,
holding
the
needle
by
the
thread
about
an
inch
there-from
,
and
in
turning
the
stone
about
,
you
shall
presently
see
the
needle
point
vnto
the
North
end
of
this
stone
,
and
flie
from
the
other
end
,
when
by
your
turning
it
commeth
neere
.
The
contrary
effect
ensueth
,
if
you
touch
the
point
of
the
Needle
with
the
other
end
of
the
stone
,
wherein
you
may
behold
that
ancient
conceiued
,
and
of
late
yeeres
maintained
errour
of
the
contrarietie
of
Magnes
and
Theamedes
to
be
nothing
else
but
a
contrarie
property
of
one
and
the
selfe
same
Magnes
.
The
third
way
.
Breake
off
the
point
of
a
sowing
needle
,
halfe
an
inch
long
or
longer
(
if
the
stone
be
good
)
but
not
aboue
a
quarter
of
an
inch
,
(
if
it
be
a
base
stone
)
lay
it
vpon
the
stone
,
and
moue
it
to
and
fro
vpon
the
Superficies
thereof
(
being
smooth
)
with
the
needles
point
forwards
,
and
as
it
commeth
neere
any
of
the
two
points
of
force
,
it
will
raise
it selfe
more
and
more
:
but
being
brought
vnto
the
point
it selfe
,
it
will
stand
there
straight
vpright
;
If
the
stone
be
ragged
this
cannot
well
be
practised
,
otherwise
of
all
other
it
is
the
most
certaine
way
.
Now
whether
it
be
your
North
or
South
end
the
effect
will
soone
declare
.
The
fourth
way
.
Hauing
an
ordinarie
Diall
with
a
magneticall
needle
,
or
a
sayling
compasse
,
or
any
magneticall
needle
standing
on
a
sharpe
pinne
,
hold
neere
thereunto
the
stone
turning
it
in
your
hand
,
then
will
the
north
end
of
the
needle
(
I
meane
the
end
that
pointeth
to
the
North
)
respect
the
true
North
point
of
the
stone
.
The
fift
way
.
Also
if
you
touch
a
common
sowing
needle
(
the
longer
the
better
)
and
put
ti
through
a
little
peice
of
corke
,
not
bigger
then
may
well
beare
it
vp
,
so
that
by
the
meanes
thereof
,
it
may
swimme
in
a
bason
of
water
,
the
same
if
you
offer
the
stone
vnto
it
,
will
shew
the
like
effect
.
And
here
it
is
to
be
remembred
,
that
none
other
way
whatsoeuer
will
more
readily
or
truely
define
the
magneticall
Meridian
,
then
this
of
the
needle
with
corcke
in
the
water
.
And
therefore
as
it
is
very
requisite
for
many
purposes
that
euery
Traueller
either
by
land
or
especially
by
sea
should
alwaies
haue
(
if
he
may
)
an
aequinoctiall
Diall
with
him
,
so
would
I
not
wish
that
any
of
them
should
be
without
some
sowing
needles
touched
with
a
good
stone
which
wil
both
serue
the
proper
vses
of
sowing
without
impairing
their
touch
(
for
it
is
open
aire
and
rust
that
are
the
greatest
enemies
thereof
)
And
at
any
time
with
a
peice
of
corcke
,
or
a
drie
sticke
in
the
water
will
shew
the
magneticall
meridian
;
a
matter
though
meane
and
triuiall
in
shew
,
yet
betweene
whiles
of
so
great
importance
that
it
may
serue
to
saue
very
many
mens
liues
.
A
sixth
way
.
Also
if
you
prepare
a
little
round
Loadstone
of
a
quarter
of
an
inch
diameter
or
there
about
(
but
it
must
be
a
very
good
one
)
hauing
his
two
poles
marked
and
fitted
in
such
manner
that
it
easily
turne
about
in
a
little
frame
according
vnto
this
picture
.
The
like
also
in
his
sort
will
come
to
passe
,
if
you
hang
a
small
declinatorie
Needle
in
a
frame
in
this
manner
.
Then
by
mouing
it
in
his
frame
all
ouer
the
stone
,
the
North
pole
of
this
will
finde
the
South
of
the
other
;
And
likewise
will
the
South
,
the
North
of
the
great
one
;
For
it
is
not
in
outward
shew
between
one
magnet
and
another
,
as
it
is
betweene
a
magnet
and
a
magneticall
needle
,
the
contrarie
ends
of
the
magnet
will
couet
in
their
motion
to
meete
together
,
but
the
end
of
the
needle
which
turneth
North
,
will
come
vnto
the
North
of
the
stone
:
For
in
very
truth
it
is
the
South
point
of
the
needle
,
euen
as
the
magnet
it selfe
being
placed
in
a
woodden
dish
in
water
will
turne
with
his
North
end
vnto
the
South
,
and
with
his
South
end
,
dish
and
all
,
towards
the
North
,
as
it
is
largely
declared
in
the
second
Chapter
of
this
booke
.
The
like
effect
will
also
follow
if
you
hang
as
aforesaid
a
small
magnet
in
the
middle
by
a
small
silke
thread
,
that
it
may
freely
turne
without
impediment
according
vnto
his
owne
nature
.
But
this
property
it
will
shew
quicker
,
or
slower
according
vnto
the
goodnesse
of
the
substance
,
and
fitnesse
of
the
forme
.
The
best
forme
for
this
purpose
is
the
extended
ovall
,
hauing
his
poles
precisely
in
his
ends
.
If
his
poles
be
some
pretty
distance
,
the
one
end
towards
the
East
of
the
stone
,
and
the
other
asmuch
towards
the
West
,
this
stone
in
his
length
will
not
point
vnto
the
magneticall
North
and
South
(
as
otherwise
he
would
)
but
vnto
some
other
point
of
the
Horizon
;
yea
following
this
experiment
in
this
sort
,
you
may
make
him
stand
vnto
any
point
of
the
Compasse
:
onely
you
ought
to
abridge
the
stone
in
his
length
that
he
may
come
somewhat
neerer
vnto
a
circuler
forme
,
that
so
his
diameter
of
North
and
South
(
being
through
the
magnetisme
of
the
earth
,
the
cause
of
this
motion
)
may
be
so
much
the
longer
in
comparison
of
the
Masse
of
the
stone
,
and
consequently
more
effectuall
.
After
the
like
manner
you
may
so
touch
the
wiers
of
a
Compasse
,
that
the
Flower
de
luce
of
the
flie
,
shall
stand
vnto
what
point
of
the
Horizon
you
please
,
although
the
Diameter
of
the
wiers
doe
still
remaine
fixed
vnder
the
Flower
de
luce
,
and
the
South
point
of
the
Carde
.
Finally
to
conclude
this
point
with
a
magneticall
delight
,
if
you
touch
two
sowing
needles
in
a
contrary
sort
,
that
is
,
the
point
of
the
one
northerly
and
of
the
other
Southerly
,
and
set
them
with
their
corckes
the
one
at
the
one
side
of
a
bason
of
water
and
the
other
at
the
other
,
you
shall
see
them
,
as
quickned
with
vitall
spirit
,
euen
so
to
moue
the
one
end
towards
the
other
,
at
the
first
faire
and
softly
,
but
when
they
draw
neere
they
will
rush
together
(
as
it
were
)
with
a
kinde
of
violence
,
the
point
of
the
one
striking
precisely
at
the
point
of
the
other
,
you
must
place
the
needle
,
whose
point
is
touched
for
the
North
on
the
South
side
of
of
the
bason
,
and
the
other
on
the
other
side
:
Otherwise
the
heads
and
not
the
points
will
runne
together
,
a
thing
farre
more
worthy
of
admiration
,
then
all
the
selfe
moouers
of
any
Daedalus
or
Architas
Tarentinus
,
and
more
strange
to
behold
then
the
connexion
of
Iron
rings
combined
by
vertue
magneticall
,
whereat
S.
Augustine
so
much
,
and
that
iustly
,
did
wonder
.
CHAP.
V.
The
manner
of
capping
both
with
single
and
double
cappes
and
the
nature
of
them
.
THe
stone
being
brought
vnto
his
perfect
forme
you
must
haue
a
mould
made
of
Iron
of
the
very
same
proportion
in
euery
respect
and
equall
in
all
his
dimensions
,
then
setting
the
stone
aside
,
let
your
workeman
frame
&
fashion
his
cappes
and
fit
them
vpon
this
mould
as
if
it
were
the
stone
,
thus
shall
you
be
sure
to
preserue
your
magnet
from
many
dangers
,
very
incident
vnto
rude
handling
:
And
hauing
so
done
you
may
set
them
on
the
stone
it selfe
,
amending
any
small
faults
,
without
endangering
the
stone
,
either
with
bruisings
,
or
knocks
;
For
the
thicknesse
and
largenesse
of
the
cappes
,
there
can
bee
no
generall
rule
prescribed
,
but
it
must
be
left
vnto
the
triall
and
ingenious
dexterity
of
the
workeman
:
as
also
for
the
handsome
fastening
either
by
soadering
,
or
riuetting
of
them
with
lattin
plates
to
the
Caps
to
keepe
them
in
their
places
firme
and
steddy
,
according
as
you
see
in
this
picture
of
a
stone
,
armed
with
single
Cappes
.
Now
therefore
in
this
position
,
both
ends
of
the
Magnet
being
applied
vnto
the
two
ends
of
the
iron
,
these
two
contrary
forces
striue
in
this
peece
of
iron
,
the
North
to
repell
the
South
,
and
the
South
the
North
:
so
that
each
force
is
driuen
neerer
his
owne
end
,
and
becommeth
there
so
much
the
stronger
then
otherwise
it
would
be
.
For
proofe
whereof
,
take
a
little
narrow
square
peece
of
iron
,
of
the
length
of
the
capped
stone
,
and
ioyned
in
the
middest
with
Copper
after
this
sort
:
A.
is
supposed
to
be
a
long
square
,
or
a
square-like
peece
of
iron
,
in
length
fitting
the
two
double
caps
of
a
Loadstone
.
B.
a
long
square
peece
,
the
ends
iron
,
the
middle
copper
.
C.
hath
a
lesse
space
of
copper
,
and
D.
least
of
all
.
If
you
apply
the
Loadstone
vnto
A
,
he
will
hold
A
very
strongly
;
but
if
you
put
any
of
the
other
three
peeces
vnder
A
,
that
it
may
touch
any
of
them
,
hee
will
not
by
any
meanes
lift
it
vp
.
If
you
apply
the
Loadstone
vnto
B
,
he
will
take
it
vp
very
weakly
,
and
C
somewhat
more
strongly
,
but
D
strongest
of
all
these
three
,
yet
not
comparable
to
the
strength
wherewith
hee
taketh
vp
A.
Againe
,
although
the
Loadstone
taketh
vp
B
but
weakly
,
yet
if
you
place
B
vpon
A
,
he
will
take
them
both
very
strongly
;
yea
more
,
place
B
vpon
C
,
these
two
vpon
D
,
all
three
vpon
A
,
apply
the
Loadstone
vnto
B
,
being
the
vppermost
,
and
he
will
lift
them
all
vp
very
easily
.
The
cause
hereof
is
,
when
a
Loadstone
with
his
double
cappe
is
placed
vpon
A
,
the
force
of
both
ends
striuing
in
that
peece
of
iron
paralel-wise
vnto
the
Axis
of
the
stone
,
the
North
and
South
forces
are
driuen
more
closely
vnto
their
proper
ends
.
But
in
B
,
(
because
of
the
intermediate
copper
)
there
can
be
no
such
close
driuing
of
his
forces
into
their
proper
ends
,
as
was
in
A
:
and
therefore
the
Loadstone
lifteth
vp
B
,
but
only
as
if
his
two
ends
were
two
little
loose
peeces
of
iron
,
hanging
in
the
aire
,
and
the
intermediate
copper
a
burthen
vpon
them
.
But
placing
B
vpon
A
,
A
in
the
manner
(
as
it
were
)
of
a
bridge
,
ioyneth
the
two
ends
together
into
their
former
combats
,
and
the
two
ends
of
B
,
forasmuch
as
they
are
but
(
as
it
were
)
two
loose
peeces
of
iron
hanging
in
the
aire
,
the
two
forces
of
the
Loadstone
North
and
South
,
distinctly
and
seuerally
passe
thorow
them
downwards
into
A
,
which
it
could
not
doe
,
if
it
had
beene
one
entire
peece
of
iron
:
and
so
all
those
foure
peeces
,
being
placed
one
vpon
another
,
so
that
A
be
vndermost
,
whether
directly
or
sidewise
,
the
Loadstone
will
easily
lift
them
all
vp
,
and
not
otherwise
.
When
a
Loadstone
lifteth
vp
iron
at
one
end
onely
,
the
vertue
of
the
stone
is
infused
into
the
whole
body
downward
of
that
iron
,
if
it
be
not
very
long
.
But
when
by
the
meanes
of
the
double
cappes
,
both
ends
doe
lift
iron
ioyntly
together
,
he
infuseth
very
small
force
downeward
into
the
body
of
the
iron
that
it
lifteth
vp
for
the
forces
of
the
both
ends
are
so
striuing
in
a
collaterall
line
of
the
iron
,
paralell
vnto
the
Axis
of
the
stone
,
that
whereas
a
good
Magnet
lifting
vp
at
one
end
,
will
extend
his
vertue
downewards
twelue
or
fourteene
inches
,
in
applying
both
ends
vnto
the
iron
,
by
the
meanes
of
the
double
caps
,
hee
will
not
extend
his
force
downeward
the
distance
of
one
inch
,
nor
with
any
strength
the
distance
of
halfe
an
inch
,
as
in
this
former
example
.
Pliny
in
his
naturall
historie
writeth
,
that
Dinocrates
that
famous
Architect
builder
of
Alexandria
,
at
Ptolemies
commandement
began
to
vault
a
Temple
with
Magnets
,
that
there
might
seeme
to
hang
in
the
aire
the
image
of
his
sister
Arsinoe
,
made
of
iron
for
that
purpose
:
but
both
Dinocrates
and
Ptolemie
dying
in
the
meane
space
,
that
enterprise
ceased
.
Neither
indeed
(
if
they
both
had
liued
)
could
it
euer
haue
come
to
passe
by
that
means
,
by
reason
of
two
impossibilities
:
The
one
is
,
that
by
the
force
of
the
Loadstones
,
nothing
can
so
hang
in
the
aire
,
but
that
it
either
must
touch
the
stone
it selfe
,
or
some
other
intermediate
substance
betweene
it
and
the
stone
,
that
barreth
it
from
comming
to
the
stone
it selfe
.
For
example
,
lay
two
or
three
needles
vpon
a
smooth
table
,
put
a
siluer
or
pewter
plate
vpon
them
,
and
vpon
the
plate
a
Loadstone
,
then
lift
vp
the
plate
aloft
with
the
Loadstone
lying
still
vpon
it
,
and
you
shall
see
the
needles
hanging
indeed
in
the
aire
endlong
,
and
if
you
moue
the
stone
about
the
plate
,
following
still
vnderneath
,
but
euermore
touching
the
plate
,
which
is
the
intermediate
body
,
that
keepeth
them
from
comming
to
touch
the
stone
,
which
otherwise
by
their
naturall
inclination
very
speedily
they
would
doe
.
But
as
for
that
image
of
Arsinoe
;
how
had
it
beene
possible
for
it
to
haue
touched
at
once
,
mediately
or
immediately
,
so
great
a
number
of
Magnets
,
whereof
the
pretended
vault
must
needs
haue
consisted
?
The
other
is
,
that
such
a
multitude
of
Magnets
would
nothing
but
confound
the
one
the
others
forces
,
so
that
one
of
them
alone
being
solitarie
and
seuered
from
his
company
,
might
shew
more
force
then
al
that
insociable
societie
could
doe
,
each
one
hindering
the
efficacie
of
the
other
.
Much
like
a
teeme
of
many
horses
,
where
euery
one
drawing
his
sundry
way
,
might
soone
with
disordered
stretching
tire
himselfe
and
his
fellowes
,
but
neuer
moue
the
loade
one
iot
from
the
place
.
Insomuch
as
one
(
and
possibly
the
worst
)
would
doe
more
good
alone
,
where
hee
might
orderly
and
freely
vse
his
owne
strength
,
then
hee
and
all
the
many
of
them
could
doe
being
ioyned
together
in
vicinitie
of
bodies
,
but
extremely
distracted
through
contrarietie
of
courses
.
The
only
way
to
performe
such
a
matter
(
if
it
were
worth
a
doing
)
would
be
to
prepare
one
mightie
great
Loadstone
of
excellent
goodnesse
:
which
hauing
his
due
proportion
,
after
an
extended
ouall
forme
,
should
be
fitted
with
double
cappes
,
and
so
placed
in
the
roofe
of
a
building
,
that
his
Axis
be
paralell
to
the
Horizon
:
in
this
sort
(
out
of
all
doubt
)
a
faire
large
image
might
bee
held
vp
very
strongly
by
such
a
Magnet
,
let
the
stuffe
or
substance
thereof
be
whatsoeuer
,
(
howbeit
the
lighter
the
better
)
so
that
there
be
fastened
vnto
the
vppermost
part
of
the
Image
a
small
peece
of
iron
accordingly
prepared
and
placed
for
the
two
prominent
ends
of
the
double
cappes
of
the
stone
,
to
lay
hold
thereon
.
But
enough
hereof
.
In
the
capping
of
Magnets
,
this
generall
rule
is
to
be
obserued
,
that
they
ought
to
be
made
of
the
finest
and
softest
iron
,
and
not
of
steele
:
the
waight
also
,
which
the
Magnet
taketh
vp
,
should
be
of
the
like
iron
,
and
not
of
steele
,
as
aforesaid
.
For
although
steele
retaineth
at
the
least
ten
times
as
much
vertue
as
iron
,
when
it
is
once
separated
from
the
stone
,
can
doe
;
yet
as
long
as
there
is
any
contiguitie
betweene
the
stone
and
them
,
hee
holdeth
iron
more
strongly
then
steele
.
Both
which
differences
in
either
of
them
by
manifest
experience
are
certaine
,
and
seeme
to
proceede
of
notable
fastnesse
or
closenesse
in
the
steele
aboue
the
iron
;
by
meanes
whereof
the
magneticall
vertue
doth
longer
and
more
forcibly
continue
in
that
then
in
this
:
euen
as
fire
more
mightily
possesseth
,
and
for
a
greater
space
abideth
in
stone
,
or
any
such
firme
or
solid
matter
,
then
in
wood
,
or
straw
,
or
the
like
thinne
and
hollow
substances
:
and
therefore
those
compasse-makers
,
that
make
the
wiers
of
their
flies
for
sailing
compasses
of
meere
iron
,
ought
not
by
any
meanes
to
be
suffered
:
for
to
gaine
two
pence
in
a
compasse
(
and
scarcely
that
)
they
intollerably
abuse
those
that
trauell
by
sea
,
to
their
great
danger
and
mischiefe
.
CHAP.
VI.
Of
cementing
and
peecing
of
Loadstones
.
FOr
your
Simmon
,
doe
thus
:
Take
the
fine
powder
of
a
Loadstone
,
halfe
so
much
powder
of
new
bricke
made
very
small
and
subtill
,
one
part
of
Burgundie
pitch
,
halfe
so
much
Rossen
,
a
small
portion
of
vnwrought
waxe
:
mingle
all
these
together
very
well
vpon
a
soft
fire
,
and
make
the
whole
masse
in
little
roules
.
Now
when
you
will
cement
a
stone
,
doe
thus
:
heat
the
two
peeces
of
the
stone
very
hot
,
and
likewise
the
simmon
,
then
strake
the
places
that
you
will
soder
,
ouer
with
the
simmon
very
thinly
,
and
ioyne
them
somewhat
hard
together
,
letting
them
so
stand
vntill
they
be
cold
,
and
you
shall
haue
it
fully
as
strong
,
as
if
it
were
an
entire
stone
of
it selfe
,
and
not
to
be
seuered
but
by
great
heat
of
fire
.
In
peecing
of
the
Loadstones
,
there
must
diligent
heede
be
taken
to
the
nature
of
the
Loadstone
in
generall
,
and
also
to
those
particular
peeces
which
you
would
ioyne
together
.
The
Loadstone
in
generall
(
as
it
is
shewed
before
)
that
his
force
issueth
(
as
it
were
)
from
a
center
in
the
middle
of
the
stone
,
to
all
the
superficies
thereof
vniuersally
,
but
most
strongly
vnto
the
Poles
from
the
middle
,
one
way
the
stone
is
all
of
a
Northerly
nature
,
and
all
of
it
Southerly
the
other
way
.
For
example
.
A.
must
be
ioyned
vpon
A
,
and
B.
vpon
B
:
but
if
you
ioyne
the
two
so
,
that
A.
lighteth
vpon
B
,
you
marre
the
new
Magnet
,
by
confounding
his
forces
.
Notwithstanding
if
you
like
to
ioyne
them
in
length
onely
,
not
in
thicknesse
,
then
indeed
must
you
combine
B.
and
A
,
and
not
A.
and
A
,
nor
B.
and
B
,
lest
here
also
you
incurre
the
former
inconuenience
,
of
confusion
of
forces
.
Take
another
example
:
Suppose
a
Loadstone
to
bee
long
and
somewhat
round
,
smaller
at
one
end
then
at
the
other
,
the
smaller
end
to
be
North
signed
with
A
,
the
other
South
signed
with
B
:
let
this
Magnet
bee
diuided
long-wayes
into
two
equall
parts
,
thorow
both
the
Poles
,
A.
and
B.
And
let
one
of
these
halfes
be
placed
vpon
a
peece
of
glasse
or
a
smooth
Table
;
certaine
it
is
,
that
if
you
do
offer
to
touch
A
,
of
this
,
with
A
,
of
the
other
,
this
A
will
turne
away
from
that
,
which
(
the
stone
being
entire
)
it
did
ioyne
with
before
:
Or
if
you
offer
B
,
vnto
B
,
it
will
doe
the
like
.
And
no
maruaile
,
for
in
this
case
of
touching
A
,
with
A
,
or
B
,
with
B
:
what
else
in
effect
doe
you
,
but
attempt
to
ioyne
the
two
halfes
in
length
and
that
at
like
ends
?
A
thing
directly
repugnant
to
the
principles
of
Magneticall
Philosophie
.
But
let
me
admonish
you
,
to
put
the
rounder
side
of
the
stone
downewards
,
next
vnto
the
glasse
,
that
it
may
turne
the
quicker
:
yet
if
the
stone
be
excellent
it
will
doe
the
same
also
vpon
the
flat
side
.
Moreouer
if
you
place
this
two
halfes
,
the
one
vpon
the
other
precisely
as
they
were
at
the
first
,
they
will
agree
very
well
:
because
they
are
as
one
,
and
the
selfe-same
Magnet
.
But
if
you
place
them
the
one
swaruing
from
the
other
,
at
either
end
,
then
will
A
,
of
the
one
,
turne
about
vnto
B
,
of
the
other
;
because
they
are
now
as
two
seuerall
and
diuers
Magnets
.
For
the
better
conceiuing
hereof
,
you
are
to
remember
,
that
euery
part
of
a
Loadstone
(
be
it
an
half
or
any
other
)
being
once
diuided
from
the
whole
,
is
(
as
Schoole-men
call
it
)
Totum
integrale
,
a
whole
Loadstone
by
it selfe
,
vtterly
diuerse
and
estranged
from
that
whole
,
whose
part
before
it
was
,
and
therefore
reteineth
distinctly
in
it selfe
,
all
the
properties
of
a
Loadstone
,
though
not
so
strong
,
as
the
whole
had
when
this
was
ioyned
therevnto
.
In
Loadstones
there
is
a
part
truely
said
to
be
diuided
from
the
whole
,
when
the
points
of
that
part
,
or
ends
,
or
Poles
(
and
so
,
by
necessary
consequence
,
the
Axis
and
Aequator
,
in
which
the
vniuersall
frame
of
Magneticall
power
consisteth
,
haue
a
position
diuers
from
the
Poles
or
points
of
the
whole
.
For
this
cause
,
in
the
last
example
the
one
halfe
A
:
B
:
being
supposed
to
swarue
from
the
other
halfe
B
:
A
:
at
either
end
,
must
needs
presently
be
diuided
from
it
,
and
now
cannot
be
pars
integri
,
but
is
of
necessitie
Totum
integrale
,
a
seuerall
and
absolute
Magnet
of
it selfe
,
and
so
by
an
essentiall
property
common
to
all
Magnets
,
coueteth
with
his
point
A
,
the
contrary
B
:
of
that
which
is
vnder
it
.
Wherefore
like
as
exact
agreement
is
betweene
two
Mathematicall
figures
when
being
applied
together
,
the
extreames
of
the
one
,
doe
precisely
fall
vpon
the
extreames
of
the
other
,
each
vpon
his
correspondent
extreame
,
and
is
made
one
therewith
:
euen
such
is
the
perfect
composition
or
setting
together
of
the
parts
of
a
Magneticall
body
,
and
namely
of
those
two
equall
parts
before
exemplified
,
you
must
so
ioyne
one
vpon
another
,
that
the
two
extreames
,
or
ends
,
be
alwaies
of
the
same
nature
Northerly
,
or
Southerly
,
in
both
parts
:
And
that
by
due
application
of
the
parts
,
the
two
Northerly
ends
be
vnited
,
and
become
one
,
as
also
the
two
Southerly
ends
after
the
same
manner
.
But
if
these
parts
,
being
of
equall
length
be
ioyned
longwise
,
the
North
of
the
one
,
vnto
the
South
of
the
other
;
those
two
ends
that
were
(
being
now
no
ends
but
the
iust
middle
of
one
Magnet
)
haue
lost
their
properties
which
they
had
,
when
they
were
ends
.
For
those
properties
,
by
this
vnition
,
are
abolished
:
but
their
other
ends
still
reserue
their
former
and
stronger
vertues
of
North
and
South
:
And
so
,
according
vnto
Magneticall
nature
,
one
Magnet
shall
haue
but
two
Poles
,
the
one
North
,
the
other
South
.
Againe
,
if
you
will
peece
two
Loadstones
together
in
thicknes
,
the
one
of
them
being
longer
,
than
the
other
;
then
you
must
either
cut
the
longer
,
that
it
may
be
fit
in
length
,
vnto
the
shorter
;
or
else
peece
the
shorter
in
such
sort
as
is
afore
described
that
he
be
equall
in
length
to
the
longer
,
&
what
soeuer
disorderly
parts
perhaps
shall
bee
in
any
of
them
,
they
may
,
euen
after
they
are
cemented
,
very
well
be
ground
away
.
Also
if
there
bee
holes
or
dents
,
with
little
peeces
of
Loadstones
cemented
(
their
points
being
obserued
)
they
may
be
filled
vp
,
without
any
manner
of
dammage
or
deformitie
,
no
more
than
there
had
not
been
any
such
at
all
.
And
after
this
method
you
may
(
with
labour
and
industry
)
of
many
Magnets
,
make
one
as
huge
,
and
of
what
forme
you
please
.
And
although
the
Magnets
of
this
body
,
magnetically
compact
(
as
I
haue
here
shewed
)
were
neuer
so
many
in
number
,
yet
the
whole
will
haue
but
two
principall
points
,
the
one
North
,
the
other
South
,
euen
as
if
it
were
one
naturall
Loadstone
:
and
all
of
them
will
contribute
their
forces
,
vnto
those
two
points
;
So
that
if
there
were
twenty
of
them
,
being
after
this
order
cemented
together
into
one
body
,
the
whole
would
haue
but
two
points
,
but
if
you
will
place
them
in
a
vault
,
according
to
a
Masons
trade
they
will
haue
40
points
,
twenty
North
,
and
as
many
South
,
and
will
worke
the
like
effect
in
drawing
yron
,
as
(
to
vse
the
former
grosse
similitude
)
if
a
teeme
of
horses
were
set
in
their
traces
contrary
the
one
to
the
other
,
the
one
to
pull
one
way
,
the
other
another
.
As
for
the
Turkes
Mahomet
,
hanging
in
the
ayer
with
his
yron
chest
it
is
a
most
grosse
vntruth
,
and
vtterly
impossible
is
it
for
any
thing
so
to
hange
in
the
ayer
by
any
Magneticall
power
,
but
that
either
it
must
touch
the
stone
it selfe
,
or
else
some
intermediate
body
,
that
hindreth
it
from
comming
to
the
stone
(
like
as
before
I
haue
shewed
)
or
else
some
stay
below
to
keepe
it
from
ascending
,
as
some
small
wier
that
may
scantly
bee
seene
or
perceiued
.
CHAP.
VII
.
Of
the
variation
of
the
Magneticall
Needle
with
the
Appurtenances
therevnto
belonging
.
THE
variation
of
the
Magneticall
Needle
,
being
aptly
fitted
and
placed
vpon
his
pinne
,
is
nothing
else
,
but
the
swaruing
of
the
pointing
thereof
in
the
Horizon
,
from
the
meridian
line
there
,
the
portion
of
the
Horizon
intercepted
betweene
the
true
Meridian
line
and
this
pointing
,
sheweth
of
what
quantitie
the
variation
is
,
and
giueth
it
his
name
,
to
wit
,
which
way
it
lyeth
,
either
Easterly
,
or
Westerly
,
and
it
is
obserued
by
either
end
of
the
needle
as
you
please
.
In
times
past
men
obserued
onely
by
the
North
end
of
the
needle
,
because
they
vnderstood
not
that
the
Loadstone
hath
a
South
vertue
,
as
well
as
a
North
;
And
therefore
did
touch
their
needles
and
wyars
of
their
compasses
alwaies
for
the
North
onely
,
leauing
those
ends
of
the
wyars
bare
,
that
they
might
be
refreshed
with
a
new
touch
at
any
time
afterwards
:
but
the
other
ends
they
couered
,
not
knowing
that
they
were
also
apt
to
receiue
as
forcible
a
vertue
from
the
Loadstone
for
the
South
,
as
the
other
for
the
North.
For
the
right
vnderstanding
of
the
variation
,
with
his
necessary
dependants
,
wee
must
vse
the
meanes
of
two
circles
:
The
one
of
them
I
will
call
the
Magneticall
Almicanter
;
The
other
is
already
knowne
by
the
name
of
the
Magneticall
Meridian
.
This
Magneticall
Almicanter
is
a
circle
paralell
vnto
the
Horizon
,
whose
center
is
the
verticall
point
,
and
is
described
by
the
distance
betweene
the
verticall
point
,
and
the
neerer
Pole
of
the
earth
.
The
true
Magneticall
Pole
is
the
pole
of
the
earth
;
The
magneticall
respectiue
Pole
,
or
(
which
is
all
one
)
the
Pole
of
the
Magneticall
Meridian
,
is
a
point
in
the
Magneticall
almicanter
,
distant
Easterly
or
Westerly
from
the
true
pole
as
many
degrees
in
that
almicanter
,
as
the
variation
of
that
place
containeth
in
the
Horizon
,
but
alwaies
it
is
in
the
contrary
part
of
the
true
Meridian
,
that
is
,
if
the
variation
of
the
South
point
of
the
needle
be
Easterly
the
respectiue
pole
is
Westerly
:
but
if
you
obserue
with
the
North
end
of
the
needle
,
the
respectiue
pole
and
the
variation
are
both
one
way
in
all
our
Northerne
Climates
.
If
the
variation
of
the
South
point
of
the
needle
bee
Westerly
,
then
is
the
respectiue
pole
so
many
degrees
in
the
said
almicanter
Easterly
,
and
therefore
alwaies
of
the
same
height
with
the
true
pole
aboue
the
Horizon
.
For
since
all
great
Circles
of
the
globe
doe
necessarily
cut
one
another
in
two
points
into
two
equall
parts
:
these
two
therefore
must
needes
doe
euen
so
in
the
Zenith
and
Nadir
,
by
their
very
definitions
;
So
that
these
two
points
(
the
Zenith
and
Nadir
)
are
alwaies
alike
common
vnto
them
both
,
aswell
vnto
the
true
,
as
vnto
the
Magneticall
Meridian
.
Where-hence
it
followeth
necessarily
,
that
alwaies
the
one
halfe
of
the
magneticall
meridian
is
on
the
East-side
,
and
the
other
on
the
West
side
of
the
true
meridian
,
the
common
Zenith
and
Nadir
euermore
keeping
their
equall
distances
from
the
Poles
▪
of
the
one
of
them
,
as
they
doe
from
the
other
.
For
example
:
Suppose
the
common
Zenith
to
be
in
the
Aequator
,
you
sayling
East
or
West
,
as
long
as
there
is
no
variation
,
there
is
no
magneticall
meridian
,
there
are
no
magneticall
Poles
,
but
those
of
the
world
.
But
as
soone
as
,
sayling
still
vnder
the
line
you
doe
finde
a
variation
it
is
the
magneticall
meridian
,
that
by
his
swaruing
from
the
true
meridian
of
the
world
in
the
Horizon
sheweth
the
quantity
of
the
variation
,
and
giueth
it
also
the
denomination
of
Easterly
or
Westerly
,
and
his
axis
is
the
line
of
variation
.
But
supposing
the
common
Zenith
,
to
be
in
any
paralel
,
betweene
the
Aequator
and
the
Pole
,
then
is
it
not
the
axis
,
but
some
other
Diameter
of
the
magneticall
meridian
,
which
sheweth
the
variation
in
the
Horizon
;
And
the
magneticall
meridian
euermore
cutteth
iust
so
many
degrees
of
the
magneticall
almicanter
on
the
one
side
of
the
true
meridian
,
as
the
same
Magneticall
Pole
is
distant
in
the
same
almicanter
,
on
the
other
side
of
the
true
Meridian
from
the
Pole
of
the
World
.
And
this
is
to
be
vnderstood
in
correspondent
manner
,
as
well
of
the
South
Hemisphere
,
as
of
the
North.
The
respectiue
Magneticall
meridian
(
where
any
variation
is
)
is
a
circle
that
passeth
by
the
verticall
point
and
the
Nadir
,
and
both
the
respectiue
Poles
,
crossing
the
Horizon
at
right
angles
in
the
points
of
variation
,
of
which
circle
the
line
of
variation
is
a
Diameter
,
but
where
there
is
no
variation
the
true
and
Magneticall
meridian
are
both
one
&
the
selfe
same
,
and
so
in
like
manner
are
their
Diameters
.
Those
circles
and
poles
are
tearmed
respectiue
because
that
in
euery
place
where
any
variation
is
,
the
Magneticall
needle
doth
respect
them
,
as
well
in
the
property
of
direction
,
as
in
that
of
declination
,
or
inclination
.
For
thus
also
very
well
it
may
bee
tearmed
.
By
the
property
of
direction
,
I
doe
meane
,
with
Doctour
Gilbert
,
the
Horizontall
motion
of
the
Magneticall
needle
:
By
the
declination
,
or
inclination
,
I
meane
the
descending
,
and
(
as
it
were
)
the
sinking
motion
of
the
neede
vnder
the
Horizon
,
in
his
proper
Azimath
,
or
Magneticall
meridian
;
But
if
there
be
no
variation
,
the
needle
alwaies
pointeth
vnto
the
true
Meridian
of
the
earth
,
and
towards
the
Poles
therof
,
in
both
those
properties
.
The
true
Poles
of
the
earth
(
which
are
those
two
points
equally
distant
from
each
part
of
the
Aequinoctiall
of
the
earth
are
alwaies
the
selfe
same
.
The
respectiue
Poles
alter
with
euery
Horizon
,
where
there
is
any
variation
,
but
neuer
out
of
the
aforenamed
almicanter
of
that
place
.
The
causes
of
the
differences
of
the
respectiue
Poles
and
Meridians
from
the
true
Poles
and
meridians
,
and
so
of
all
variations
,
are
onely
two
;
The
chiefe
and
most
generall
is
the
vastenesse
of
the
Ocean
sea
,
by
moistnesse
whereof
the
Magneticall
collaterall
force
of
so
much
earth
as
it
couereth
,
is
much
hindered
and
dulled
.
And
by
that
meanes
the
next
great
Continent
hath
more
power
ouer
the
correspondent
end
of
the
Magneticall
needle
,
then
otherwise
it
could
haue
if
all
were
alike
one
entire
Continent
:
and
therefore
causeth
the
directiue
property
of
the
needle
somewhat
to
swarue
towards
that
way
,
which
is
that
,
which
we
call
variation
;
but
yet
the
vastenesse
of
the
Ocean
doth
not
hinder
the
declination
of
the
Magneticall
needle
;
Because
his
hangings
consisteth
but
in
length
and
breadth
,
and
not
in
depth
.
For
although
in
comparison
of
a
pond
or
riuer
,
the
sea
is
said
to
be
of
a
wonderfull
depth
,
yet
if
this
depth
be
compared
with
a
Semidiameter
of
the
earth
,
it
beareth
a
very
exceeding
small
proportion
,
nothing
at
all
to
hinder
the
mightie
magneticall
declinatory
force
of
the
whole
earth
;
For
the
greatest
depth
that
euer
any
man
of
skill
esteemed
it
at
,
was
not
aboue
two
English
mile
,
at
the
vttermost
,
when
as
daily
experience
maketh
it
manifest
,
that
a
great
Continent
wil
shew
his
Magneticall
collaterall
force
,
by
causing
a
variation
,
aboue
two
hundred
miles
of
from
the
place
,
and
therefore
Doctor
Gilberts
feare
in
that
point
I
take
to
be
needlesse
,
supposing
a
variation
of
declination
.
The
second
cause
of
variation
,
is
any
great
mountainous
region
not
farre
of
,
when
a
man
is
in
some
great
Latitude
towards
either
of
the
Poles
:
if
that
mountainous
region
lie
Easterly
or
Westerly
from
you
,
it
will
cause
the
needle
somewhat
to
swarue
that
way
.
But
variations
of
this
sort
are
of
small
continuance
,
and
in
sayling
subiect
vnto
sudaine
alterations
,
yea
many
times
quite
contrary
from
Westerly
to
Easterly
&
afterwards
backe
againe
within
short
space
:
as
our
first
famous
Pilote
Steuen
Burrough
found
by
his
experience
in
the
discouery
of
the
Scythian
sea-coast
between
the
north
Cape
of
Finmarke
and
Vaygates
.
The
reason
whereof
ought
heedfully
to
be
regarded
which
is
that
the
Magneticall
force
of
the
whole
earth
,
doth
(
as
in
all
Magnets
)
shew
it selfe
most
strongely
in
the
two
Poles
thereof
,
and
in
those
places
which
are
neere
vnto
them
:
but
alwayes
it
must
be
remembred
,
that
all
the
force
they
haue
doth
issue
out
of
the
whole
terrestriall
body
,
as
it
doth
likewise
in
all
Magnets
out
of
the
body
of
the
Magnet
:
and
therefore
in
any
part
of
the
superficies
of
the
whole
terrestriall
body
,
it
is
impossible
that
any
variation
be
aboue
90.
degrees
,
because
the
vertue
of
the
whole
can
neuer
bee
ouerswaied
by
the
imperfection
of
a
part
,
and
especially
of
so
small
a
part
as
any
one
portion
of
the
Ocean
is
in
his
very
superficies
,
in
respect
of
the
body
of
the
whole
earth
:
yea
I
am
thorowly
perswaded
,
that
there
neuer
was
nor
euer
will
bee
any
variation
,
by
any
good
obseruation
found
for
to
bee
so
much
as
ninety
;
neither
any
shew
of
so
great
variation
any
where
,
except
it
bee
very
neere
vnto
either
of
the
Poles
,
where
there
is
small
credit
to
be
giuen
to
the
obseruing
of
any
variation
:
for
the
variation
being
(
as
aforesaid
)
the
difference
of
the
pointing
of
the
magneticall
Needle
in
the
Horizon
from
the
true
Meridian
,
for
asmuch
as
in
places
neere
the
Pole
,
there
is
no
manner
of
certaintie
of
either
of
these
,
it
is
not
possible
to
finde
the
variation
,
if
there
be
any
.
The
reason
whereof
is
this
,
no
man
may
trauell
those
Seas
,
but
whiles
the
Sunne
abideth
on
that
side
of
the
Aequator
,
whereby
they
haue
continuall
day
,
and
by
that
meanes
are
secluded
from
any
helpe
of
the
starres
,
neither
if
they
might
bee
seene
,
would
they
bring
any
great
helpe
.
For
the
difference
of
heighth
in
many
houres
is
so
small
,
that
by
a
very
large
instrument
a
diligent
obseruer
with
great
paines
will
hardly
finde
the
Meridian
Line
,
all
the
Meridians
themselues
comming
so
neere
one
to
another
,
and
meeting
in
the
Pole
,
and
their
Horizon
being
in
a
manner
paralell
vnto
the
Aequinoctiall
.
And
as
for
the
horizontall
magneticall
Needles
,
to
shew
their
pointing
in
the
Horizon
as
they
were
wont
to
doe
,
they
comming
into
this
climate
may
say
,
Fuimus
Troes
.
Their
direction
is
as
it
were
giddy
and
vncertaine
,
and
when
their
center
commeth
vnto
the
Pole
it selfe
,
it
is
quite
vanished
away
;
for
from
thence
all
the
points
of
the
Horizon
are
onely
South
,
if
it
be
at
the
North
Pole
,
and
North
from
the
South
Pole
,
and
therefore
in
that
place
the
instrument
of
declination
is
farre
more
sure
then
the
Horizontall
Compasse
.
And
as
in
the
Poles
themselues
there
is
no
direction
at
all
,
so
of
necessitie
neere
vnto
them
it
must
bee
a
very
confused
direction
.
Those
two
places
,
that
are
called
the
Poles
,
haue
no
strength
of
themselues
(
as
aforesaid
)
but
as
it
is
contributed
vnto
them
of
the
whole
.
As
in
a
Magnet
,
if
you
breake
off
a
peece
of
the
contrary
end
,
the
end
that
is
left
will
bee
according
vnto
that
proportion
diminished
in
his
strength
,
and
the
polar
peece
,
that
was
broken
off
(
be
it
neuer
so
little
)
will
haue
two
poles
as
well
as
the
great
:
so
that
the
two
parts
will
haue
foure
Poles
,
two
of
them
North
,
and
two
South
.
Put
this
little
peece
that
was
broken
off
,
in
his
place
againe
,
and
then
each
peece
will
lose
one
of
his
Poles
in
the
same
very
instant
,
and
the
whole
will
haue
but
two
Poles
,
the
one
North
,
the
other
South
,
as
at
the
first
.
Againe
,
if
you
cut
off
a
peece
of
one
side
of
a
Loadstone
,
that
is
brought
into
a
round
or
an
ovall
forme
,
hauing
his
Poles
marked
in
their
due
places
at
each
end
,
presently
both
end
will
be
abridged
of
part
of
the
force
they
had
,
and
the
Poles
themselues
will
be
remoued
vnto
the
other
side
,
from
the
places
that
were
marked
,
and
those
markes
will
stand
but
for
idle
ciphers
in
comparison
of
that
they
were
before
.
Againe
,
take
a
Magnet
of
a
round
or
an
extended
ovall
forme
,
(
I
doe
still
exemplifie
in
these
,
because
they
are
of
all
others
,
as
I
haue
often
admonished
,
for
all
magneticall
proofes
the
most
excellent
formes
)
and
set
markes
on
the
two
Poles
,
take
a
fine
needle
,
or
any
straight
small
wier
,
and
set
it
on
the
aequinoctiall
,
(
I
meane
thereby
the
middle
betweene
the
two
ends
of
the
stone
)
then
will
it
point
directly
towards
each
Pole
,
if
the
stone
bee
sound
without
any
flawes
,
or
any
other
grosse
substance
(
as
may
bee
)
intermingled
with
it
:
and
if
you
thrust
this
needle
towards
either
end
,
according
vnto
his
owne
direction
he
will
trace
you
a
circle
right
ouer
both
of
these
marked
Poles
,
which
is
the
true
Meridian
of
the
stone
.
But
if
this
stone
hath
in
either
of
the
sides
any
imperfection
,
when
the
needle
commeth
vnto
the
edge
or
brinke
thereof
,
it
will
swarue
somewhat
towards
the
sounder
side
,
and
will
point
to
neither
of
the
true
Poles
.
And
if
a
circle
bee
drawne
according
to
his
pointing
,
as
hee
standeth
still
in
that
place
,
this
shall
be
a
respectiue
Meridian
of
that
stone
,
proper
vnto
that
place
:
and
the
Poles
.
the
respectiue
Poles
,
differing
from
the
true
Meridian
of
the
stone
and
his
Poles
.
Now
if
you
thrust
the
needle
further
towards
the
end
,
vpon
the
brinke
of
this
imperfection
,
it
will
not
point
(
as
before
)
but
either
further
off
,
or
neerer
towards
the
true
Poles
▪
and
will
giue
his
direction
for
a
new
respectiue
Meridian
;
and
new
respectiue
Poles
,
And
in
such
manner
infinitely
,
if
you
place
the
needle
in
the
middle
of
this
imperfection
,
equally
distant
from
the
sound
parts
,
then
will
it
indeede
poynt
towards
the
true
Poles
of
the
stone
,
And
the
Consequence
heereof
is
the
maine
reason
,
that
towards
the
midst
of
the
Ocean
;
and
likewise
of
any
great
continent
there
is
no
variation
.
Thus
may
you
especially
in
a
round
Loadstone
(
as
in
a
liuely
example
)
see
the
true
causes
of
all
the
variations
that
are
in
the
whole
world
,
reckoning
as
much
space
as
the
Ocean
couereth
,
to
bee
some
imperfection
in
the
body
of
the
whole
,
in
respect
of
the
Horizontall
motion
of
the
Compasse
.
For
the
euidence
of
the
truth
heereof
,
let
a
man
examine
generally
the
variations
of
our
most
expert
Nauigators
(
Although
by
reason
of
their
diuersities
of
the
sets
of
their
Compasses
,
and
vnfitnesse
and
vnapt
handling
of
their
instruments
,
they
very
seldome
times
agree
among
themselues
)
obserued
in
the
Atlanticke
Ocean
,
from
the
Aequator
vnto
the
parts
of
Norway
,
all
along
the
East
coast
from
the
Meridian
of
the
Azores
:
And
in
like
manner
from
the
Aequator
to
the
parts
of
New-found-land
and
vpwards
,
all
along
the
Westerne
Coast
from
the
Azores
,
as
farre
North
,
as
heereunto
hath
beene
discouered
,
and
he
shall
finde
the
ordinary
practise
to
testifie
the
truth
heereof
,
as
also
after
the
same
sort
from
the
Aequator
Southward
vnto
the
straights
of
Magellan
,
and
all
along
the
backeside
of
America
in
the
South
Sea
:
and
on
the
East
Coast
vnto
the
Cape
of
Bona
speranza
,
and
he
shall
perceiue
the
like
agreement
:
But
in
sailing
from
the
Cape
of
Bona
speranza
,
farther
Eastward
,
that
sometime
they
doe
finde
it
otherwise
,
the
cause
is
the
different
manner
of
the
scituation
of
the
South
,
as
yet
vndiscouered
Continent
.
And
wheras
in
the
middest
of
the
Atlanticke
Ocean
,
about
30.
leagues
Westwards
from
the
Azores
,
they
find
no
variation
at
all
,
no
maruell
thereof
:
For
it
is
about
the
middle
distance
betweene
the
two
great
Continents
of
America
and
ours
.
Wherefore
the
round
Loadstone
is
significantly
termed
by
Doct.
Gilbert
Terrella
,
that
is
,
a
little
,
or
rather
a
very
little
Earth
:
For
it
representeth
in
an
exceeding
small
modell
(
as
it
were
)
the
admirable
properties
magneticall
of
the
huge
Globe
of
the
earth
.
Heerein
also
wee
may
beholde
the
reason
why
,
the
magneticall
needle
varieth
least
in
the
Aequinoctiall
,
and
most
towards
the
Pole
,
and
in
the
Poles
themselues
giueth
no
direction
at
all
:
For
proofe
heereof
,
take
a
needle
and
place
it
vpon
the
Aequinoctial
of
the
stone
,
there
you
shal
see
him
stand
equally
ballanced
and
very
strongly
,
so
that
if
you
turne
him
from
his
direction
,
as
soon
as
you
let
him
goe
,
hee
will
presently
turne
vnto
it
againe
.
The
reason
is
,
because
each
Pole
doth
equally
strengthen
his
correspondent
end
of
the
needle
.
Mooue
this
needle
toward
either
of
the
Poles
,
then
doth
the
neerer
Pole
strengthen
his
end
of
the
needle
;
but
the
farther
(
because
of
the
distance
)
cannot
doe
the
like
vnto
his
,
but
very
weakly
,
and
this
needle
will
not
stand
any
more
equally
ballanced
(
as
it
did
in
the
Aequinoctiall
)
but
that
end
next
the
Pole
will
couch
downe
,
and
the
other
will
rise
vp
.
For
on
the
North
side
of
the
Aequator
,
the
true
South
end
is
predominant
,
and
on
the
other
the
North
end
hath
the
mastery
.
And
that
this
is
also
in
the
earth
it selfe
,
all
our
late
Trauellers
confirme
vnto
vs
by
their
daily
experience
,
and
all
the
very
Artizans
and
needlediall-makers
in
the
world
must
needes
be
daily
witnesses
of
it
.
As
for
example
:
Let
any
workman
in
our
Climate
make
a
needle
for
a
diall
,
when
he
hath
fitted
it
and
placed
it
on
the
pinne
,
that
it
may
stand
thereon
equally
ballanced
and
paralell
to
the
Horizon
touch
it
with
the
Magnet
,
then
presently
that
which
pointeth
towards
the
North
will
hang
downe
(
yea
,
although
you
touch
onely
with
the
South
end
)
and
will
not
stand
,
as
before
the
touch
equally
ballanced
and
paralell
to
the
Horizon
:
except
you
cut
or
file
somewhat
from
that
end
,
that
hangeth
downe
;
or
else
adde
a
peece
of
waxe
or
some
other
thing
vnto
the
other
end
of
the
needle
to
counterpoise
it
,
and
make
it
stand
equidistant
as
it
did
at
the
first
setting
on
:
and
this
is
a
thing
very
certaine
,
that
this
Northerly
descent
of
the
needle
,
will
be
more
or
lesse
in
all
places
of
Northerly
Latitude
:
In
the
greater
Latitude
the
more
,
and
in
the
lesser
Latitude
the
lesse
.
But
if
any
traueller
carry
this
needle
beyond
the
Aequator
in
the
like
Latitude
Southerly
,
that
end
which
tendeth
downewards
in
the
Northerly
,
will
rise
vp
in
the
Southerly
,
and
the
other
sincke
downe
,
euen
as
much
:
and
the
neerer
you
trauaile
towards
either
Pole
,
the
more
,
that
end
which
pointeth
towards
the
Pole
,
will
tend
downewards
:
This
is
most
certaine
in
euery
Diall-needle
:
but
a
great
deale
more
apparant
it
is
in
a
long
one
,
then
it
is
in
a
short
one
.
Wee
cannot
find
that
the
property
of
direction
by
the
Magnetical
needle
hath
beene
vulgarly
practized
(
for
sailing
)
much
aboue
200.
yeeres
.
And
as
for
the
property
of
declination
vnder
the
Horizon
,
thereby
to
shew
the
Latitude
by
the
Instrument
thereunto
belonging
,
it
is
as
yet
a
very
new-come
guest
into
the
world
,
borne
and
bred
with
vs
in
England
,
and
(
except
it
bee
in
exceeding
few
mens
hands
)
not
yet
in
vse
,
much
lesse
come
vnto
his
perfection
.
But
this
it
not
to
be
maruelled
at
:
because
it
is
scantly
sixteene
yeeres
olde
;
neither
is
it
to
bee
wondred
if
any
Criticall
fellowes
doe
contemne
and
deride
it
.
Forasmuch
as
either
their
want
of
knowledge
,
or
of
patience
,
will
not
giue
them
leaue
truely
to
consider
of
it
.
But
what
Nauigator
,
or
rather
Nugator
soeuer
contemneth
it
,
shall
bee
sure
to
repent
it
if
euer
hee
come
to
his
right
wits
to
consider
what
it
is
that
he
hath
contemned
.
And
although
the
needles
for
direction
and
declination
doe
differ
much
in
their
shapes
,
each
from
other
;
yet
the
properties
are
both
one
and
the
selfe
same
.
For
the
needles
for
direction
doe
decline
(
as
aforesayd
)
as
farre
as
the
vnfitnesse
of
their
forme
and
placing
will
permit
them
:
and
the
declining
needle
will
not
worke
,
but
onely
in
his
Magneticall
Meridian
,
which
himselfe
will
finde
out
,
if
you
turne
the
Instrument
about
,
vntill
the
needle
shew
his
least
declination
vnder
the
Horizon
,
and
there
doe
play
vp
and
downe
&
stop
in
the
end
in
the
same
place
again
.
But
if
you
would
haue
a
needle
fitted
to
shew
both
properties
,
doe
thus
,
cause
a
needle
to
bee
made
a
bout
sixe
inches
long
,
euen
and
smooth
,
sauing
that
he
must
be
a
little
bigger
in
the
middle
,
then
insteed
of
an
Axis
(
which
declinatory
needles
haue
)
let
him
haue
a
small
hole
drilled
precisely
in
the
middest
,
and
this
hole
being
very
small
,
let
it
bee
somewhat
wider
outwards
on
each
side
then
in
the
middest
,
(
which
our
workmen
call
sinckboared
)
where
it
must
bee
left
very
sharpe
,
euen
almost
as
the
edge
of
a
knife
:
put
through
this
hole
a
small
verginall
lattine
wiar
,
and
fit
the
needle
so
that
it
hang
precisely
euen
vpon
this
wiar
,
insteed
of
an
Axletree
:
then
touch
him
with
the
Loadstone
,
and
you
shall
presently
see
the
end
that
should
point
towards
the
North
,
decline
or
bend
downe
to
his
due
place
of
declination
,
if
he
be
placed
in
the
Magneticall
Meridian
;
set
a
little
peece
of
waxe
or
any
other
thing
vpon
the
contrary
part
for
a
counterpoyse
that
the
needle
may
stand
paralell
with
the
Horizon
,
then
if
it
stand
at
right
angles
with
that
verginall
wiar
,
it
is
certainly
in
the
Magneticall
Meridian
:
otherwise
it
will
neuer
stand
at
right
angles
,
but
will
make
his
sharper
angle
alwayes
towards
the
Magneticall
Meridian
.
So
that
hanging
in
this
counterpoise
if
you
turne
about
the
wiar
vntill
the
needle
doe
make
right
Angles
with
it
,
then
doth
the
needle
by
his
directiue
vertue
poynt
vnto
the
Magneticall
Meridian
line
.
Take
off
the
counterpoise
,
then
it
sheweth
the
declination
for
that
place
,
and
by
consequent
the
Latitude
,
if
you
in
that
manner
place
him
in
the
Instrument
of
declination
;
so
that
one
and
the
selfe
same
needle
in
the
same
place
onely
,
by
taking
off
,
and
putting
on
a
little
peece
of
wax
,
sheweth
plainely
both
those
properties
of
directions
and
declinations
,
as
in
like
manner
euery
inclinatory
needle
will
doe
,
if
the
poynts
of
his
Axis
be
sharpe
,
and
held
in
his
boxe
paralell
vnto
the
Horizon
,
he
will
shew
both
those
properties
of
direction
and
declination
:
A
fine
peece
of
corcke
or
leather
,
or
any
tough
snbstance
may
serue
this
needle
for
a
counterpoyse
in
all
Latitudes
by
thrusting
it
towards
the
center
in
lesse
Latitudes
,
and
towards
the
end
in
the
greater
,
and
I
thinke
it
not
impossible
,
but
that
a
skilfull
Geometrician
may
so
graduate
the
one
halfe
of
such
a
needle
,
that
it
alone
with
his
counterpoyse
,
may
bee
a
meanes
to
giue
a
probable
coniecture
for
the
Latitude
of
any
place
whatsoeuer
.
CHAP.
VIII
.
A
discouery
of
errours
committed
in
making
and
touching
Magneticall
Needles
and
Wyars
of
sayling
Compasses
,
with
an
aduise
for
the
true
and
right
making
and
touching
of
them
.
FIrst
the
wyars
that
are
commonly
made
both
with
vs
,
and
in
forraine
countries
,
are
of
so
base
and
drossie
iron
,
not
apt
nor
sufficient
to
receiue
the
tenth
part
of
the
vertue
that
fine
steele
wyar
could
doe
.
Secondly
,
the
ends
of
the
wiars
bee
for
the
most
part
not
filed
smooth
nor
fitted
euen
together
vpon
the
Axis
of
the
flie
;
By
meanes
whereof
the
touch
of
the
stone
is
more
dully
receiued
,
and
the
standing
of
the
flie
,
the
more
vncertain
,
the
magneticall
force
not
being
in
the
true
axis
thereof
.
The
reason
heere
of
is
this
,
the
Magnet
giueth
his
force
(
Secundum
mensuram
recipientis
)
according
to
the
capacity
of
that
which
receiueth
it
,
and
that
euer
more
after
his
owne
nature
,
which
is
to
haue
his
force
strong
in
his
ends
,
and
none
at
all
in
the
middle
,
if
you
touch
the
blade
from
the
middle
,
with
either
end
of
the
stone
,
the
other
end
of
the
haft
will
immediate
receiue
and
shew
the
contrary
quality
:
euen
so
also
will
it
come
to
passe
,
if
you
make
proofe
with
any
Magneticall
needle
,
although
that
his
force
will
bee
faint
and
weake
in
comparison
of
the
other
.
And
in
your
touching
you
must
obserue
,
that
in
pressing
with
the
stone
from
the
middle
of
the
needle
vnto
the
end
,
as
you
bring
your
hand
backward
to
iterate
the
touch
,
you
must
lift
your
hand
somewhat
high
,
and
not
bring
it
backeward
,
close
to
the
needle
.
For
that
would
diminish
the
strength
of
the
touch
.
But
if
that
end
of
the
needle
be
also
touched
with
the
other
end
of
the
stone
,
in
manner
as
aboue
I
haue
rehearsed
,
then
shall
hee
at
each
end
be
a
great
deale
the
more
strong
,
and
the
contrary
fainter
forces
shall
recoile
and
settle
in
the
middle
of
the
needle
,
where
they
can
nothing
at
all
disturbe
the
motion
thereof
.
CHAP.
IX
.
Of
the
touching
with
a
Laadstone
capped
and
without
the
cappe
.
BY
capping
,
is
meant
the
placing
of
two
peeces
of
iron
handsomely
fitted
and
fastened
vpon
the
two
points
of
the
stone
,
for
iron
for
this
purpose
is
better
then
steele
.
And
likewise
concerning
the
the
waight
that
is
to
bee
lifted
vp
,
it
is
better
to
bee
made
of
soft
iron
then
of
steele
,
and
the
stone
will
lift
more
therof
,
as
long
as
there
is
contiguity
:
but
if
if
the
iron
and
steele
be
separated
from
the
contiguity
of
the
stone
,
the
steele
will
alwayes
carry
at
the
least
tenne
times
more
vertue
then
the
iron
,
as
is
before
mentioned
.
Now
whether
it
were
best
to
touch
the
wiers
with
a
Magnet
being
thus
capped
,
or
with
the
bare
stone
it selfe
,
some
there
be
that
make
a
question
.
I
haue
beene
tolde
by
one
of
great
skill
and
practise
,
that
he
found
by
experience
,
the
Compasse
touched
with
a
capped
stone
,
not
to
receiue
his
force
so
well
,
as
the
other
,
and
the
party
comming
vnto
me
,
when
he
was
to
vndertake
a
long
voyage
,
to
haue
his
compasse
touched
,
requested
mee
in
any
wise
to
doe
it
with
the
bare
stone
:
But
yet
I
thinke
it
were
good
,
that
this
bee
confirmed
by
more
then
one
mans
experience
,
before
it
be
beleeued
,
because
by
some
error
he
might
possibly
mistake
the
matter
.
Sure
I
am
that
the
capped
stone
giueth
somewhat
more
vertue
in
his
touch
,
and
by
all
experience
that
I
haue
made
,
I
finde
it
to
continue
as
firmely
and
as
long
.
Howbeit
I
referre
mee
heerein
to
the
ttiall
of
others
also
.
A
man
may
therefore
touch
the
wiars
first
with
the
bare
stone
,
&
then
with
the
same
being
capped
,
or
contrariwise
to
bee
surer
of
the
greater
force
,
and
yet
if
any
shall
imagine
the
difference
of
the
strength
of
the
touch
,
to
be
according
to
the
taking
vp
of
iron
with
the
cap
or
without
it
,
he
is
very
greatly
deceiued
.
For
I
haue
often
tried
them
both
,
but
neuer
could
see
the
touching
strength
in
the
needle
to
be
increased
halfe
a
quarter
more
with
the
cap
then
without
it
;
whereas
I
haue
alwayes
(
especially
if
the
stone
were
very
good
)
found
that
the
stone
wil
lift
at
the
least
ten
times
as
much
iron
:
yea
,
a
great
deale
more
,
(
and
sometimes
twenty
times
)
with
the
cap
(
if
it
be
artificially
fitted
)
then
he
is
able
to
doe
without
it
.
Some
,
who
would
seeme
to
be
of
great
skill
,
haue
imagined
,
that
the
best
way
to
adde
strength
to
a
needle
,
is
with
a
hammer
to
giue
some
forcible
strokes
to
one
point
of
the
stone
,
thereby
causing
litragges
(
as
it
were
)
or
beard
,
to
hang
downe
from
it
,
&
that
the
needle
in
his
touching
,
taking
some
part
of
that
with
him
,
should
haue
the
stronger
touch
.
But
they
that
so
suppose
deceiue
themselues
therin
:
for
that
beard
is
nothing
else
,
but
the
fine
dust
of
the
stone
,
hanging
together
by
vertue
thereof
:
which
being
separated
from
the
stone
(
although
it
were
a
right
good
one
)
is
not
able
any
whit
at
all
to
turne
a
needle
of
it selfe
.
The
triall
is
soone
made
by
this
meanes
,
let
them
take
of
that
beard
from
the
stone
with
a
sticke
,
and
lay
it
vpon
the
end
of
a
needle
not
touched
,
and
they
shall
finde
in
it
no
force
at
all
,
nay
it
is
a
hurt
vnto
the
needle
.
For
it
giueth
a
superfluous
burthen
for
a
small
time
,
and
cannot
but
incumber
his
action
,
by
reason
that
euery
one
of
those
little
parcels
of
dust
(
though
beaten
out
at
one
end
)
hath
also
for
his
small
quantity
both
a
North
and
South
vertue
.
And
therefore
marreth
as
much
as
it
maketh
at
either
end
of
the
needle
.
The
proofe
heereof
is
manifest
,
if
you
put
off
that
dust
or
beard
vpon
a
paper
,
and
hold
a
Magnet
therunder
,
for
as
you
turne
towards
the
paper
the
North
or
South
of
the
stone
,
so
will
euery
one
of
those
particles
in
like
sort
turne
it selfe
,
shewing
thereby
a
double
nature
.
CHAP.
X.
Of
the
fashioning
of
the
compasse
needle
.
THe
Compasse
needle
,
being
the
most
admirable
and
vsefull
instrument
of
the
whole
world
,
is
both
amongst
ours
and
other
nations
for
the
most
part
,
so
bungerly
and
absurdly
contriued
,
as
nothing
more
.
And
therefore
entreating
now
of
the
nature
and
vse
of
the
Magnet
.
I
haue
thought
good
,
also
,
to
employ
my
best
endeauour
,
to
aduance
this
noblle
instrument
towards
his
highest
perfection
,
being
the
principall
thing
,
by
which
the
worthy
effect
of
the
Magnet
,
is
made
most
profitable
vnto
mankinde
.
Heerein
fiue
things
are
to
be
considered
,
the
substance
that
it
is
made
of
,
the
forme
,
the
waight
,
the
capitell
,
and
the
pin
it
standeth
vpon
:
The
substance
in
any
wise
ought
to
bee
pure
steele
,
and
not
iron
.
For
most
assuredly
steele
will
take
at
the
least
tenne
times
more
vertue
then
iron
can
doe
,
but
especially
if
it
hath
his
right
temper
.
And
that
is
this
:
Heat
it
in
the
fire
vntill
it
be
past
red
hot
,
that
it
be
whitish
hot
and
qnench
it
in
cold
water
suddenly
:
So
is
it
brickle
in
a
manner
as
glasse
it selfe
,
and
is
at
that
time
incapable
of
the
vertue
of
the
Loadstone
.
Then
must
you
,
laying
it
vpon
a
plaine
table
,
warily
rubbe
with
fine
sand
all
the
blacke
cullour
from
it
,
if
before
you
put
it
into
the
fire
,
you
annoynt
it
with
soape
,
it
will
scale
white
of
it selfe
,
then
heat
a
barre
of
iron
well
neere
red
hot
,
and
holding
one
end
of
the
needle
with
a
small
paire
of
tongs
,
lay
the
other
end
vpon
the
hot
barre
,
and
presently
you
shall
see
that
end
turne
from
white
to
a
yellowish
,
and
after
to
a
blewish
cullour
,
then
take
that
end
with
your
tongs
,
and
doe
thlike
vnto
the
other
,
thrusting
it
forward
vpon
the
barre
vntill
the
cullour
of
the
whole
needle
become
blewish
:
then
throw
it
on
a
table
,
and
let
coole
of
it selfe
:
and
so
is
he
of
the
excellentest
temper
,
and
most
capable
to
receiue
the
greatest
power
from
the
Magnet
.
If
this
seeme
too
curious
especially
for
some
fashions
of
needles
,
then
vse
but
the
hammer
hardening
(
as
workmen
call
it
)
which
is
well
neere
as
good
.
As
concerning
the
forme
,
diuers
men
are
of
diuers
mindes
,
some
vse
a
kind
of
square
one
,
others
a
loop
(
I
meane
an
extended
ouall
forme
)
and
this
is
most
common
.
But
now
a
dayes
,
a
narrow
straight
place
(
being
somewhat
broader
in
the
middle
)
is
in
great
request
:
Of
these
three
I
holde
the
loope
or
ouall
forme
(
if
it
bee
well
made
)
to
bee
the
best
,
which
is
,
that
if
it
be
of
steele
,
his
ends
be
welded
together
,
hauing
a
lattin
narrow
plate
,
issuing
from
the
capitell
vnto
the
middle
of
the
two
sides
of
the
Loope
,
and
there
riuetted
,
and
riuetting
,
if
it
bee
handsomely
shouldered
in
by
the
workman
,
is
better
then
soadering
:
because
,
hauing
fitted
the
lattin
plate
bearing
the
capitell
vnto
the
Loope
,
you
may
first
put
your
Loope
into
his
temper
,
and
then
riuet
this
vnto
him
afterwards
,
which
otherwise
would
bee
marred
in
the
fire
,
and
the
wide
Loope
is
better
then
the
narrow
or
the
straight
plate
,
and
that
for
two
reasons
.
The
one
is
,
hecause
,
as
in
a
Magnet
it selfe
,
the
force
that
is
in
the
whole
body
,
sheweth
it selfe
most
strongly
in
his
two
poles
,
euen
so
this
being
a
Magneticall
body
,
doth
the
like
in
his
ends
which
are
his
poles
:
and
the
sides
of
a
wide
compassed
Loope
(
being
longer
,
then
of
a
narrower
)
of
the
same
length
,
in
the
Axis
,
must
needes
containe
so
much
the
more
vertue
;
the
other
reason
is
,
because
it
supposeth
the
flie
in
his
circular
motion
more
equally
ballanced
then
the
other
:
and
therefore
were
it
not
for
some
other
inconueniences
,
a
true
circle
were
best
of
all
,
which
is
that
except
you
marke
the
two
places
,
that
you
would
haue
for
the
North
and
Souch
,
very
curiously
,
you
shall
neuer
giue
him
the
right
touch
:
yea
,
very
exceeding
hardly
,
although
you
doe
marke
them
;
and
also
the
lattin
stay
,
that
holdeth
the
capitell
,
would
bee
exceding
long
and
a
superfluous
burden
:
but
the
very
best
forme
of
all
(
as
I
take
it
)
in
all
respects
is
this
,
a
true
circle
,
hauing
his
Axis
going
out
beyond
the
circle
,
at
each
end
narrow
and
narrower
,
vnto
a
reasonable
sharpe
point
,
and
being
pure
steele
as
the
circle
it selfe
is
,
haning
in
the
middest
,
a
conuenient
receptacle
to
place
the
capitell
in
.
This
circle
must
haue
foure
very
small
holes
drilled
through
it
,
equally
distant
each
from
other
,
for
the
foure
cardinall
points
,
and
in
both
the
two
poynts
,
that
issue
without
the
circle
,
being
for
North
and
South
of
equall
distance
betweene
the
circle
and
the
end
of
the
poynt
two
moe
,
if
it
be
a
large
one
,
otherwise
one
is
enough
,
according
vnto
this
picture
following
.
And
this
needle
is
most
fit
to
be
vsed
for
the
obseruation
of
the
variation
alone
without
any
flie
,
as
I
will
shew
at
the
latter
end
of
this
Treatise
.
Whensoeuer
you
wil
set
this
needle
vnto
the
fly
,
you
must
put
the
capitell
through
the
center
of
the
flie
very
precisely
,
and
placing
the
points
of
the
Diameter
where
you
will
haue
them
,
thrust
little
small
pins
through
the
vpper
face
of
the
flie
,
and
those
small
holes
in
the
needle
,
the
heads
of
the
pinnes
will
shew
you
(
if
the
flie
bee
larger
then
your
needle
)
at
what
poynt
your
needle
standeth
,
and
bowing
the
body
of
your
pinnes
(
being
thrust
through
those
little
holes
)
close
to
the
card
below
,
will
keep
it
steddy
at
that
place
,
and
from
warping
also
.
And
so
foure
pins
at
the
foure
cardinall
points
will
serue
the
turne
.
Againe
,
if
you
please
for
to
place
this
needle
vpon
the
vpper
face
of
the
Card
according
vnto
Steuinius
.
it
is
no
more
but
to
haue
the
capitell
loose
,
thrust
thorough
the
center
in
the
bottome
of
the
flie
,
and
the
needle
placed
and
fastened
on
the
top
,
or
vpper
face
of
the
carde
.
But
if
you
will
haue
a
Magneticall
needle
to
serue
onely
for
one
size
of
a
flie
,
the
best
way
is
,
insteed
of
the
two
pinnes
in
the
ends
of
the
Axis
,
to
haue
a
couple
of
little
halfe
staples
and
a
Flower
de
luce
on
one
of
them
,
as
you
see
in
the
Loope
,
riuetted
there
.
That
in
turning
about
the
needle
,
they
may
still
keep
the
flie
close
vnto
it
,
and
so
fasten
it
with
a
skrew
vpon
the
capitell
wheresoeuer
you
please
.
As
for
his
waight
it
must
bee
according
vnto
his
largenesse
,
and
the
waight
is
one
principall
cause
,
that
very
large
compasses
are
vnprofitable
.
For
the
waight
of
the
large
carde
,
and
heauy
needle
,
pressing
vpon
the
pinne
,
will
cause
the
motion
of
the
flie
to
be
dull
and
vncertaine
,
and
therefore
let
the
pastboard
be
no
heauier
then
you
must
needes
;
and
for
the
size
of
sixe
inches
Diameter
of
your
past-board
,
and
a
needle
of
that
length
.
I
know
that
a
needle
of
halfe
an
ounce
waight
,
and
halfe
a
quarterne
at
the
vttermost
(
if
a
good
workman
haue
it
in
hand
)
will
be
very
fully
sufficient
,
of
what
forme
soeuer
.
The
capitell
ought
to
be
lattin
,
and
hammer
hardned
,
well
and
truely
boared
,
not
too
shallow
,
but
of
a
good
conuenient
depth
and
widenesse
at
the
bottome
,
fitting
the
pinne
it
standeth
vpon
at
the
top
.
The
pinne
ought
to
be
either
of
lattin
,
or
copper
,
and
not
of
iron
or
steele
,
as
some
vse
;
for
they
are
very
subiect
to
rust
:
and
the
steele
,
especially
by
long
vse
,
will
weare
a
little
hole
in
the
top
of
the
capitell
,
and
by
that
meanes
the
Compasse
becommeth
dull
,
and
they
hardly
(
if
euer
)
will
find
the
reason
of
it
;
for
the
hole
will
bee
passing
small
,
and
entring
an
exceeding
little
way
in
,
and
yet
disturbeth
all
.
Moreouer
,
in
any
wise
there
must
bee
alway
an
especiall
diligent
care
had
of
fitnesse
betweene
the
capitell
and
the
pinne
.
Oteerwise
,
all
things
else
appertaining
vnto
the
compasse
are
nothing
worth
.
This
pinne
must
bee
very
firmely
fixed
in
the
iust
center
of
the
boxe
,
and
the
bottome
marked
,
that
whensoeuer
you
take
it
off
to
sharpen
the
pin
(
which
vse
will
make
blunt
)
you
may
set
him
in
the
same
place
againe
.
As
I
haue
sayd
that
in
a
Magnet
it selfe
,
the
vertue
is
in
the
whole
body
,
and
sheweth
it selfe
most
forcible
in
his
poles
;
euen
so
likewise
our
Compasse-needle
,
being
a
Magneticall
body
,
sheweth
his
force
in
his
ends
,
which
are
his
poles
,
although
that
force
doth
proceede
out
of
the
whole
body
of
the
Needle
.
Which
now
I
thought
good
to
make
apparant
by
an
euident
demonstration
:
I
caused
my
workeman
to
make
a
needle
of
a
Loop
fashion
,
8.
inches
long
,
or
ouall
forme
in
all
respects
fitted
to
be
set
vnto
a
flie
,
sauing
that
there
was
but
one
inch
or
a
little
more
at
each
end
of
steele
,
all
the
intermediate
part
between
the
two
ends
,
being
of
brasse
:
These
two
ends
I
did
touch
with
the
North
and
South
ends
of
a
very
good
Magnet
:
And
whereas
in
a
true
Magneticall
Needle
,
I
should
haue
had
but
two
points
,
the
one
North
and
the
other
South
,
this
Mongrell
yeelded
me
six
,
the
two
ends
adioyning
vnto
the
brasse
of
contrary
natures
vnto
the
sharpe
points
,
&
would
no
more
doe
the
office
of
a
Magneticall
needle
then
a
woodden
sticke
,
because
the
vertue
was
not
in
the
whole
,
and
so
communicated
vnto
the
two
ends
,
but
each
end
was
a
totall
of
himselfe
,
being
separated
,
and
(
as
it
were
)
diuorced
,
the
one
from
all
community
with
the
other
by
that
intermediate
brasse
:
the
which
being
taken
away
,
and
the
two
forkes
ioyned
together
for
that
length
,
presently
they
became
one
perfect
true
Magneticall
Needle
,
and
the
vertue
of
those
foure
confused
points
,
which
ere
while
was
was
lost
in
the
forkes
,
will
presently
bee
found
in
the
two
sharpe
ends
,
and
now
his
naturall
seats
:
Both
these
ends
of
steele
were
fastened
vnto
the
brasse
,
and
then
that
needle
had
no
Magneticall
motion
;
but
being
taken
off
,
and
ioyned
together
,
they
presently
(
without
any
further
touching
of
them
)
became
a
true
Magneticall
Needle
.
To
conclude
this
chapter
of
the
Compasse-needle
,
The
needle
that
is
still
working
vpon
his
pinne
continually
will
keepe
his
force
better
,
then
that
which
is
otherwise
layd
vp
,
although
there
bee
no
doubt
of
the
other
,
for
a
mans
whole
age
,
or
longer
,
if
it
be
of
good
mettall
,
and
kept
from
open
aire
and
rust
,
and
from
too
neere
vicinity
of
iron
,
but
especially
of
any
Loadstone
.
No
better
keeping
from
rust
,
then
by
varnishing
him
,
although
it
be
but
with
a
drop
or
two
of
Linseed
oyle
alone
;
the
needle
that
is
continually
vpon
his
pinne
,
is
still
strengthened
by
the
Magneticall
power
of
the
earth
,
setting
himselfe
alwayes
towards
the
Poles
thereof
(
which
the
other
cannot
doe
)
and
needeth
onely
to
haue
his
pinne
sharpned
now
and
then
:
The
which
of
all
the
faults
incident
vnto
the
Compasse
,
is
most
easily
and
safely
amended
.
And
yet
,
if
it
bee
not
very
well
looked
vnto
,
it
disturbeth
all
the
operation
of
the
Compasse
more
then
any
other
.
And
diuers
wrong
themselues
in
being
too
busie
in
often
touching
of
their
Compasses
,
the
fault
being
in
this
which
no
touching
can
amend
.
CHAP.
XI
.
A
Sayling
Compasse
fitted
for
obseruing
at
Sea
the
variation
,
amplitude
of
either
sunne
or
starres
,
capes
or
trendings
,
&c.
I
Haue
thought
good
to
conclude
this
short
Treatise
of
Magneticall
aduertisements
,
with
a
little
additament
vnto
the
ordinary
sayling
Compasse
,
fitting
him
thereby
to
bee
answerable
vnto
the
title
heere
prefixed
,
as
also
with
a
comparison
of
the
seuerall
vses
,
of
the
Horizontall
and
inclinatory
needles
:
Let
the
glasse
of
the
inner
boxe
of
the
Compasse
bee
of
good
thicknesse
and
strength
(
but
yet
cleere
)
and
euen
,
those
that
come
from
Venice
for
looking
glasses
before
the
foile
be
set
on
are
the
best
,
if
a
man
may
haue
them
large
enough
.
Let
this
glasse
be
very
well
fitted
vnto
the
boxe
,
and
simmond
vnderneath
vpon
the
shouldring
that
beareth
vp
the
glasse
,
with
a
mixture
of
waxe
,
turpentine
,
sallet
oile
and
rosin
mingled
together
:
or
with
any
other
simmon
as
you
shall
thinke
good
,
aboue
vpon
the
glasse
let
there
be
a
ring
of
thin
pastboard
,
of
the
bredth
of
the
shouldring
vnderneath
,
in
like
manner
simmoned
on
:
then
must
you
haue
a
circle
of
lattin
about
the
bredth
of
the
pastboard
ring
,
of
conuenient
thicknesse
for
strength
:
which
must
bee
diuided
into
degrees
:
This
circle
must
haue
a
plate
of
latten
,
of
halfe
an
inch
broad
or
broader
,
according
vnto
the
largenesse
of
the
circle
for
strength
,
that
must
crosse
ouer
the
middest
of
the
circle
,
cut
out
of
the
same
place
with
the
circle
,
or
else
so
adered
with
siluer
so
ader
:
this
must
haue
a
line
all
along
the
middest
of
it
,
and
a
little
loope
at
each
end
cut
through
the
two
ends
of
the
loopes
being
precisely
in
that
line
.
Last
of
all
,
you
must
haue
a
moueable
ruler
with
two
long
folding
sights
,
of
about
the
length
of
the
Semidiameter
of
the
circle
in
bredth
about
halfe
an
inch
:
the
one
of
them
must
haue
a
slit
through
the
length
thereof
,
of
about
a
quarter
of
an
inch
broad
,
as
you
shall
thinke
conuenient
,
and
two
little
holes
,
the
one
in
the
top
,
and
the
other
in
the
bottome
,
iust
in
the
middle
of
it
,
to
fasten
a
string
,
hauing
a
very
little
bead
to
slide
vp
and
downe
vpon
it
.
And
this
sight
must
be
of
the
thicker
stuffe
then
the
other
.
For
otherwise
,
because
of
that
which
is
cut
out
,
it
would
be
ouerpaised
by
the
other
,
and
so
the
boxe
would
swarue
towards
the
other
;
and
the
sights
must
each
of
them
haue
a
little
notch
in
the
middest
of
the
top
of
them
:
this
ruler
must
be
fastened
(
but
yet
so
that
he
may
turne
about
)
in
the
middle
of
the
crosse
plate
most
precisely
in
the
center
of
the
circle
,
his
ends
cut
,
that
he
may
shew
the
Fiduciall
line
in
the
diuisions
of
the
circle
,
the
other
sight
needeth
to
bee
but
a
a
plaine
plate
,
hauing
a
line
in
the
middle
,
from
the
top
to
the
bottome
.
The
description
followeth
,
being
the
very
same
in
substance
with
that
,
which
in
the
Nauigators
Supply
,
I
call
the
Compasse
of
variation
;
although
all
things
easier
performed
with
this
,
then
with
that
,
The
Picture
.
The
Vses
.
The
Compasse
being
thus
fitted
,
place
the
circular
needle
described
in
the
sixth
chapter
,
vpon
his
pin
alone
without
any
flie
.
For
being
disburdened
of
the
card
,
he
will
shew
his
vertue
the
more
strongly
,
and
being
of
that
for
me
he
will
ballance
himselfe
sufficiently
.
Place
the
circle
vpon
the
glasse
and
pastboard
,
in
such
sort
that
you
may
turne
the
circle
round
about
,
very
close
and
euen
,
within
the
brim
of
the
boxe
.
When
you
will
set
the
same
vnto
the
Compasse
,
turne
the
circle
about
,
vntill
thorough
the
Loopes
of
the
middle
stay
or
plate
,
you
see
the
Axis
of
the
needle
right
vnder
the
Fiduciall
line
of
the
middle
stay
,
then
holding
the
circle
so
,
turne
the
mooueable
ruler
with
the
stringed
sight
towards
the
sunne
,
vntill
the
shadow
of
the
string
fall
vpon
the
fiduciall
line
of
the
moueable
ruler
,
for
then
doth
the
end
of
the
ruler
,
among
the
degrees
,
shew
the
true
place
or
Azimuth
of
the
sunne
from
the
Magneticall
Meridian
,
so
that
two
obseruations
,
the
one
in
the
forenoone
,
the
other
in
the
afternoone
,
thus
made
,
with
the
seuerall
heights
of
the
Sunne
,
being
one
and
the
very
same
,
halle
the
differences
of
those
places
of
the
sun
,
from
the
Magneticall
needle
is
the
variation
.
As
for
example
,
if
the
ends
of
the
ruler
did
cut
forty
in
the
forenoone
,
and
fifty
in
the
afternoone
,
the
difference
is
then
,
the
halfe
therof
fiue
:
so
much
must
the
variation
be
Westward
.
If
a
man
haue
no
exact
instrument
to
take
the
height
of
the
sunne
,
hee
may
make
some
reasonable
shift
,
by
setting
the
little
bead
towards
the
top
of
the
string
,
that
it
may
in
the
forenoone
cast
a
shadow
vpon
the
Fiduciall
line
of
the
ruler
;
and
marking
that
place
with
any
thing
(
as
inke
or
blacke
lead
)
in
the
afternoone
attend
,
vntill
the
shadow
of
the
bead
(
the
bead
remaining
still
where
it
was
)
fall
vpon
that
place
.
For
then
shall
you
haue
that
same
height
,
if
you
will
take
the
amplitude
of
the
suns
rising
or
setting
,
set
the
circle
,
and
turne
the
ruler
,
as
before
,
vntill
the
shadow
of
the
string
do
fall
vpon
the
middle
line
of
the
other
sight
.
Then
doth
the
end
of
the
ruler
shew
,
how
farre
the
sunne
riseth
or
setteth
from
the
magneticall
Meridian
.
When
you
will
take
the
amplitude
of
the
rising
or
setting
of
any
starre
,
you
must
vse
the
helpe
of
another
,
to
holde
the
circle
ouer
the
needle
(
as
before
)
and
so
you
turning
the
ruler
,
vntill
you
see
the
starre
in
his
rising
or
setting
,
through
the
two
Notches
on
the
tops
of
the
sights
,
then
doth
the
end
of
the
ruler
shew
your
desire
,
The
like
is
to
be
done
in
obseruing
any
cape
,
or
the
trendings
of
any
land
for
the
dedescription
of
any
Coast.
CHAP.
XII
.
A
comparison
of
the
seuerall
vses
of
the
Horizontall
and
inclinatory
Magneticall
Needles
.
THe
Horizontall
and
inclinatory
motions
of
Magneticall
needles
are
both
of
them
but
one
and
the
selfe
same
effect
of
the
Magnet
or
Loadstone
,
the
making
of
the
Horizontall
or
Diall-needle
,
is
among
our
artificers
very
well
known
and
triuiall
,
only
they
are
to
be
put
in
minde
that
they
doe
alwaies
make
them
of
pure
steele
and
not
of
iron
.
But
as
for
the
making
of
the
inclinatory
needles
,
it
is
a
very
curious
peece
of
worke
:
It
must
be
of
pure
steele
,
and
in
his
right
temper
,
the
needle
and
his
axis
must
bee
at
right
angles
the
one
with
the
other
,
and
must
bee
so
hanged
on
the
two
ends
of
his
axis
that
hee
bee
very
pliant
for
his
motion
,
and
that
(
before
he
haue
his
touch
)
he
bee
so
equally
ballanced
,
that
the
one
end
be
not
one
iot
heauier
then
the
other
,
for
if
it
be
,
all
the
rest
is
in
vaine
.
When
you
will
vse
the
inclinatory
instrument
,
thus
you
must
doe
,
hanging
him
by
his
little
ring
,
turne
him
about
vntill
hee
make
his
least
declination
(
or
inclination
)
vnder
the
Horizon
of
the
instrument
:
for
then
is
hee
iust
in
his
Magneticall
Meridian
,
and
there
sheweth
his
due
poynt
,
the
which
otherwise
he
can
neuer
do
.
But
here
I
must
admonish
you
of
two
very
great
errors
published
in
the
contriuing
of
this
noble
instrument
.
The
one
is
,
that
he
would
haue
a
little
box
with
an
Horizontall
Needle
fastened
vnto
the
bottome
of
the
inclinatory
instrument
:
for
to
direct
the
instrument
vnto
the
Magneticall
Meridian
:
and
by
his
picture
of
the
Instrument
,
the
distance
should
be
but
a
little
more
then
an
inch
,
where
it
is
impossible
but
that
the
one
needle
must
needes
disturbe
the
other
,
so
that
neither
of
them
can
shew
aright
,
yea
,
although
they
were
six
inches
asunder
,
and
more
,
where
the
little
box
will
giue
little
direction
for
that
purpose
?
and
besides
that
,
it
is
altogether
vnnecessary
,
because
the
instrument
will
finde
the
Magneticall
Meridian
,
by
the
least
declination
of
the
needle
(
as
is
shewed
before
)
vnder
the
Horizon
,
without
the
helpe
of
any
other
.
The
other
error
is
this
,
that
he
would
haue
that
end
of
the
needle
prepared
to
hang
towards
the
North
,
to
bee
framed
somewhat
higher
then
the
other
,
as
is
vsuall
in
Horizontall
needles
:
what
workman
soeuer
obserueth
this
direction
,
I
will
assure
him
,
that
hee
shall
lose
his
labour
,
and
assoone
hee
may
wash
a
Blacke-moore
white
,
as
to
make
such
a
needle
serue
that
turne
.
The
reason
is
,
because
it
is
onely
the
magneticall
vertue
that
worketh
this
effect
,
the
which
ouerwaight
,
in
either
end
of
the
needle
(
in
this
motion
)
doth
vtterly
ouerthrow
.
For
Horizontall
needles
in
our
Northerne
Climates
,
it
is
necessary
:
but
for
inclinatory
needles
,
it
is
vtterly
vntrue
in
all
Climates
of
the
whole
world
wheresoeuer
.
The
motion
of
the
Horizontall
needle
,
is
naturally
stronger
then
the
inclinatory
for
two
causes
,
The
one
is
because
his
motion
is
onely
sidewaies
,
the
which
is
easier
for
the
Magneticall
motion
to
worke
in
,
then
that
which
is
vp
and
downe
,
and
that
there
is
no
difference
which
way
you
place
the
boxe
wherein
he
standeth
,
so
that
it
bee
paralell
vnto
the
Horizon
;
whereas
the
inclinatory
motion
is
in
a
verticall
circle
vp
and
downe
,
and
must
stand
onely
in
his
Magneticall
Meridian
to
performe
his
office
.
The
other
cause
is
because
of
the
diuersity
of
their
placing
in
their
boxes
:
for
the
Horizontal
needle
standeth
more
fitter
for
his
motion
,
being
placed
with
his
capitell
vpon
the
poynt
of
his
sharpe
pinne
,
than
the
inclinatory
can
doe
,
being
placed
vpon
the
two
ends
of
his
axis
,
although
neuer
so
neere
the
poynts
:
But
yet
he
will
doe
very
well
,
if
he
be
rightly
fitted
:
And
for
Nauigation
vnder
either
Pole
(
if
there
be
any
passage
that
way
)
it
is
the
onely
Instrument
of
the
world
.
For
where
the
Horizontall
needle
(
or
compasse
)
faileth
,
he
is
strongest
,
for
the
neerer
the
Pole
,
the
stronger
he
is
in
his
Motion
,
contrariwise
,
it
is
with
the
Horizontall
needle
or
compasse
,
for
he
is
strongest
at
the
Aequinoctial
,
and
of
no
force
vnder
the
Pole
.
The
reason
whereof
is
this
,
vnder
the
Aequinoctiall
the
Horizontall
needle
standeth
paralell
vnto
the
Axis
of
the
earth
,
and
is
equally
strengthened
for
his
motion
with
the
two
poles
of
the
earth
:
but
vnder
the
poles
,
hee
standeth
crosse-wise
,
at
right
angles
with
the
Axis
,
his
center
representing
the
very
pole
of
the
earth
it selfe
;
so
that
the
Aequinoctiall
,
and
the
Horizon
being
there
all
one
,
if
the
needle
should
haue
any
Horizontall
motion
there
,
it
must
needes
be
an
East
or
West
motion
paralell
vnto
the
Aequinoctiall
,
directly
contrary
vnto
nature
,
and
to
all
Magneticall
doctrine
.
Yet
at
the
pole
,
the
inclinatory
needle
is
in
his
cheefest
strength
,
framing
himselfe
to
bee
in
the
same
direct
line
with
the
Axis
of
the
earth
it selfe
:
so
that
the
vicinity
of
the
neerest
pole
of
the
earth
,
holdeth
his
conuenient
end
of
the
needle
most
strongly
,
being
nothing
at
all
hindered
by
the
aduerse
pole
,
to
affect
the
vpper
(
or
other
)
end
of
the
needle
.
The
which
in
all
other
scituations
either
more
or
lesse
it
doth
,
and
especially
vnder
the
Aequinoctiall
,
where
each
pole
affecting
his
conuenient
end
of
the
inclinatory
needle
,
it
must
stand
very
goglingly
and
vnsteddily
for
that
motion
:
although
most
strongly
for
the
Horizontall
,
if
you
place
him
accordingly
.
Where
hence
it
followeth
,
that
neere
the
Aequinoctiall
large
compasses
,
and
small
inclinatories
are
fittest
;
and
neere
the
poles
large
inclinatories
,
and
small
compasses
are
best
,
for
looke
vnto
what
motion
the
Magneticall
force
is
weakest
,
the
smaller
instruments
ought
for
to
be
applied
.
And
moreouer
,
for
as
much
as
the
Magneticall
reuolution
of
the
inclinatory
needle
,
about
the
globe
of
the
earth
maketh
his
motion
for
the
difference
of
euery
alteration
of
Latitude
neere
vnto
the
Aequinoctiall
,
farre
more
large
&
easier
to
be
discerned
,
then
it
can
be
neere
the
poles
,
therefore
a
lesse
Instrument
will
serue
the
turne
there
:
And
because
that
neere
the
pole
,
his
motion
for
differences
of
Latitudes
are
exceeding
small
,
and
hard
to
be
discerned
.
Therefore
very
large
instruments
inclinatory
are
there
to
bee
vsed
,
especially
because
the
Magneticall
strength
of
the
needle
for
that
motion
,
is
there
so
strong
and
steddy
,
that
it
maketh
som
recompence
for
the
slowuesse
of
his
moouing
.
And
therefore
I
suppose
that
three
in
Diameter
,
will
serue
neere
the
Aequinoctiall
,
and
fifteene
neere
the
Pole
.
And
because
this
great
one
may
be
the
lesse
cumbersome
,
you
may
cut
off
the
circle
at
forty
and
fiue
degrees
of
each
side
of
the
Zenith
and
Nadir
of
the
Instruments
,
and
yet
leaue
the
needle
scope
enough
,
for
all
Latitudes
between
sixty
Degrees
and
the
Pole
:
and
for
the
the
steddy
standing
of
the
inclinatory
instrument
at
the
sea
,
you
may
doe
thus
:
about
the
middle
of
the
instrument
(
or
rather
somwhat
aboue
the
middle
)
let
there
be
two
round
pins
of
brasse
,
about
three
quarters
of
an
inch
long
,
issue
out
;
and
in
a
box
of
a
sayling
Compasse
,
the
inner
circle
being
taken
away
,
make
of
each
side
two
halfe
round
notches
in
the
outer
circle
,
there
place
the
Instrument
vpon
those
two
pins
,
the
which
must
haue
towards
their
ends
,
littles
circles
cut
in
,
that
they
slip
not
out
of
their
rings
that
they
are
placed
in
:
then
will
this
Instrument
stand
as
steddy
,
euen
at
sea
,
as
the
sayling
compasse
will
doe
:
for
the
motion
of
the
inner
circle
is
performed
by
the
turning
of
those
two
pins
in
their
notches
,
and
the
outer
circle
is
common
vnto
them
both
,
alwaies
remembring
that
you
hang
some
pretty
waight
in
the
bottome
of
the
instrument
,
to
make
his
motion
more
certaine
:
If
the
shaddowing
of
the
box
hinder
your
sight
from
discerning
the
point
,
that
the
needle
standeth
at
,
it
is
soon
holpen
with
the
light
of
a
little
waxe
candle
put
downe
vnto
it
:
and
yet
this
you
ought
to
vnderstand
as
aforesayd
,
that
the
Horizontal
and
inclinatory
motions
are
but
one
and
the
selfe
same
effect
of
the
touch
of
the
Loadstone
,
and
one
and
the
selfe
same
needle
will
very
well
performe
both
motions
,
namely
,
the
inclinatory
needle
,
not
the
Horizontall
,
because
his
placing
vpon
the
pinne
maketh
him
very
vnfit
for
the
inclining
motion
.
But
the
inclinatory
needle
resting
with
one
poynt
of
his
Axis
(
the
poynts
of
his
Axis
being
very
sharpe
)
in
his
little
hole
,
his
boxe
being
placed
paralell
vnto
the
Horizon
,
will
performe
the
Horizontall
motion
very
well
.
For
being
placed
with
the
sharp
point
of
his
axis
in
that
hole
,
it
is
all
one
in
effect
,
as
the
Horizontal
is
with
his
capitel
on
the
sharp
point
of
his
pin
,
but
that
the
one
is
vpward
and
the
other
downward
,
&
yet
either
of
them
being
as
fit
for
that
motion
,
as
the
other
.
Vpon
the
consideration
hereof
,
my
workman
of
Winchester
minding
to
present
Prince
Henry
with
a
rare
Instrument
,
contriued
an
Aequinoctiall
Diall
&
an
Inclinatory
Instrument
both
in
one
,
and
one
needle
to
serue
very
well
both
those
turnes
.
Heerein
now
appeareth
the
wonderfull
wisdome
of
our
God
,
in
limitting
his
times
and
seasons
for
the
reuealing
of
these
wonderfull
properties
for
the
vse
of
men
,
in
this
poore
stone
;
namely
that
aboue
2000.
yeeres
after
that
it
was
knowen
and
wondred
at
in
the
world
,
for
lifting
vp
of
iron
(
for
it
was
an
antiquity
in
Platoes
time
)
the
vse
of
the
Horizontall
needle
was
known
,
in
common
vse
,
scant
200.
yeeres
agone
;
and
very
few
yeeres
since
(
yea
scant
as
yet
)
the
inclinatory
is
in
any
common
vse
:
and
who
is
there
that
can
behold
and
consider
both
these
vses
,
viz.
both
to
shew
the
quarters
of
the
world
(
as
East
,
West
,
North
and
South
,
&c.
)
and
also
the
Latitude
of
the
place
:
to
know
both
these
in
any
place
of
the
world
,
bee
the
heauens
neuer
so
much
ouercast
with
clowds
,
who
is
he
,
I
say
,
that
can
beholde
these
two
admirable
and
precious
vses
performed
,
euen
with
the
turning
of
an
hand
,
the
which
neither
the
Grecian
Philosophers
,
nor
the
fine-witted
Romans
,
nor
the
Persian
Magi
,
nor
the
Indian
Gymnosophists
could
finde
out
with
all
their
skill
and
cunning
,
but
he
must
needs
say
with
that
Kingly
Prophet
,
O
Lord
,
our
Lord
,
how
great
is
thy
name
through
all
the
Earth
,
who
hast
set
thy
glory
aboue
the
Heauens
?