A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2022 May 11, 06:02 -0700
While trying to find the Vol.1 of the "Hints to Travellers" Edition 9, I stumbled upon Edition 5 from the year 1883.
On pages 73 and 74 it presents a graphical way to clear a lunar distance.
As usual (for the otherwise nice book) there is no explanation - why and how it does work.
After several readings and re-readings I got a slight idea on what they are talking about. Apparently they ask to take the lengths of the segments equal to the values of chords of the relevant angles. And - finally - to measure the resulting segment's length to convert it back to the angular value.
Still I'm puzzled by the VooDoo of the method, can't even guess where those magical divisors (53 and 62) come from.
I'd be glad to get some insights on that.
Thank you in advance.
Also I'd like to get the Vol.1 Ed.9 too!