A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2016 Dec 7, 19:17 -0800
A few days ago the weather cooperated and I managed to take a PM sight when the sun was on the prime vertical.
ho 35° 50.1'
GPS 41° 06.5' 175° 05.2'
t 61 22' by calculator
GHA 246° 16.8'
From which long = 175° 05.2' !!!!!!!!
From Norie A = .46 B = .46 C = 0
so azimuth = N 90° W
Error in long = error in lat * C = 0
I recalculated t for lat +- 6' and confirmed that there was no error in long. A lat error of +-30' gave a small error in long.
There isn't anything particularly amazing in the above except that it confirms what I learned four decades or more ago. A method used by 19th century navigators really does work!!!!!!!
The telescopes on my sextant do not work (I am missing a tube) and usually I use a sight tube. For the above sight I used the binoculars with one objective covered with a piece of thick card. The larger images made it much easier to touch limbs.