NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Patrick Goold
Date: 2011 Jan 14, 14:00 -0500
Puzzle 1: the d a the bottom of the NA pages for Jan 13,14,15 has no units. I gather from what you say that the units are minutes of arc. Is that right? So we are talking a very small correction here.
Puzzle 2: I don't see the increments table giving me any fractions. How do you get your one half? I look at the table for 30 minutes 00 seconds and I get a number in the "sun/planets" column of 7º 30' and in the first column to the right of the double line (which I think is the one I am supposed to be looking at) labelled "v or d corrn" I see two entries <0.0'. 0.0'> What am I not seeing?
Best regards and with gratitude for your help,
Patrick
Patrick,
I believe the d value you are referring to is the hourly change of declination. The minutes and seconds of time increments in the back of the Nautical Almanac will give you the fraction of the d value to add or subtract from the whole hour declination figure. For example if making an observation on the half hour then half of the 0.4' d value (-0.2') would be subtracted from the south declination on your January 14th date. During periods near the solstice the "d" value is small and conversely large near the equinox.
Greg Rudzinski
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--
Dr. Patrick Goold
Department of Philosophy
Virginia Wesleyan College
Norfolk, VA 23502
757 455 3357
Charles Olson: "Love the World -- and stay inside it."
