NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: UNK
Date: 2012 Oct 3, 11:14 -0700
List,
I would like some help in identifying the diagram between pages 14 and 15 of the this book: http://archive.org/details/primerofcelestia006282mbp
Here is some accompanying text of the OCR scan:
Outer circumference represents the celestial sphere in the
plane of its equator seen from north.
p at top is "First Point of Aries" from which right ascension
is counted in a circle divided into 24 hours, numbered counter-
clockwise. These are shown in the 2nd band....
Fifty-five navigational stars including Polaris whose right
ascensions and declinations change very little are shown in
the outer band in approximately correct positions. Those with
a minus sign added are o southern declination and lie below
(behind) the diagram while all others are of northern declina-
tion above (in front of) the diagram. These are the stars for
which complete data are given in the Nautical Almanac and
which are most easily used for position finding.
The 12 "Signs of the Zodiac" are included in the 3rd band
for popular interest only. ......
The 4th band of months is for locating the earth in its orbit.
The five circles outside the sun as labeled are for the orbits
of the earth and the four planets used in navigation, with their
periods of rotation, all counterclockwise.
The "spokes" are to show two-hourly intervals of R. A.
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