A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2020 Apr 23, 15:23 -0700
Here are some observations I have made during the lockdown.
The format of 249, which was published in the early 1950s is IMHO logical. The page is selected by latitude same/contrary. On each page dec is tabulated horizontally and LHA tabulated vertically.
Contrast this with 229 which was published in the 1970s. Assume I want H & Z for lat 40° LHA 30°. The page numbers refer to my particular volume. On p62 I find LHA 30°, lat same as dec. On p63 is also LHA 30° but for contrary names. On each page lat is tabulated horizontally from 30° to 37° and LHA vertically.. Obviously the next page will be LHA 30°, lat 38°- 45° so all I have to do is turn the page.
When I turn the page I am very confused. P64 is LHA 31° lat 30° to 37°. To cut a long story short I hunt through the pages until I reach P244 and find LHA 30° dec 30° - 45°.
Maybe there is a logical reason that this illogical (to me) format was chosen? Is it one of the reasons that 249 is used today rather then the newer 229. Note that I am using NP 401 (3) aka HD 605 (III). I wonder if the UK version was assembled differently to the US version?