1065534r
1.
Of the manner to observe the variation of
compasse, or of the wires of the same, by the sonnes
rising or
Of the manner to observe the variation of
compasse, or of the wires of the same, by the sonnes
rising or
There are two sortes of compasse ordayned for the the observatioobserving the variation of the
wires; one hath a moveable fy fly; the other hath none. The flour de
lure or north poynt of the fly standeth directly with the fly wires in both.
And the utmost circle of both is devided in to poynts & degrees; there being
11 degrees & a quarter betwixt poynte & This being rememebred of your compasses. Then for your observat-
on you are to do the l as
wires; one hath a moveable fy fly; the other hath none. The flour de
lure or north poynt of the fly standeth directly with the fly wires in both.
And the utmost circle of both is devided in to poynts & degrees; there being
11 degrees & a quarter betwixt poynte & This being rememebred of your compasses. Then for your observat-
on you are to do the l as
In the morning or eveninge when you may see the sonne rise or set
(your compasse standing fit;) you are to marke upon what
how many degrees
the sonne riseth from the East poynt of the comp fly; or setteth from
the west, & note whether to the southwardes or northwards; this observation
& as many as you can make enter into your booke; noting the day & place
that where you made
(your compasse standing fit;) you are to marke upon what
how many degrees
the sonne riseth from the East poynt of the comp fly; or setteth from
the west, & note whether to the southwardes or northwards; this observation
& as many as you can make enter into your booke; noting the day & place
that where you made
Then for the finding of the variation, I have calculated a speciall
table for the purpose; whose title is A table for the sonne rising
& setting from the true East & West. which you are to use in
this manner. first consider what declination the sonne hath
that present day which you may know by your Regiment; Also what
is the elevation of the pole at that plane, which you are to know upon
reckoning from your last
table for the purpose; whose title is A table for the sonne rising
& setting from the true East & West. which you are to use in
this manner. first consider what declination the sonne hath
that present day which you may know by your Regiment; Also what
is the elevation of the pole at that plane, which you are to know upon
reckoning from your last
Then in the sayd table of thes onnes rising & setting loke in the
head of the table the degrees of the sonnes declination; & on left right
side or left of the table loke the Degree of elevation & right agaynst the
same under the declination you efore noted; (in the common angle)
you shall find how much the sonne riseth or setteth from the true east
or west in degrees & minuts. rising is always to the northward
if the sonne hath north declination, or southward if the declination
be south. And this nomber of degrees & minuts for brevity & distinction
sake hereafter to be used is called the sonnes
head of the table the degrees of the sonnes declination; & on left right
side or left of the table loke the Degree of elevation & right agaynst the
same under the declination you efore noted; (in the common angle)
you shall find how much the sonne riseth or setteth from the true east
or west in degrees & minuts. rising is always to the northward
if the sonne hath north declination, or southward if the declination
be south. And this nomber of degrees & minuts for brevity & distinction
sake hereafter to be used is called the sonnes
Now to conclude how much your your compasse doth vary the breefest
& most intelligible way is this: note upon the same fly you made
your observation by, or upon any other in any booke that hath degrees
in the utmost circle, the degree that the prime rose be set upon: Then
from that marke towards the East reckon or nomber the degrees of the
sonnes Amplitude northward if the sonne hath south declination; or reckon
southward if the sonne hath north declination & where the degrees end there
is the true east or west; which being had, it self it is then manifest
both how much your compasse doth vary & which
& most intelligible way is this: note upon the same fly you made
your observation by, or upon any other in any booke that hath degrees
in the utmost circle, the degree that the prime rose be set upon: Then
from that marke towards the East reckon or nomber the degrees of the
sonnes Amplitude northward if the sonne hath south declination; or reckon
southward if the sonne hath north declination & where the degrees end there
is the true east or west; which being had, it self it is then manifest
both how much your compasse doth vary & which
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