A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2016 Aug 2, 16:22 -0700
For many years I had a passive interest in Nautical Astronomy. I studied the subject and from time to time purchased a second hand book. I formed the impression that reducing sights by the hav-cosine formula and tables such as Norie was difficult/tedious/complicated/took a long time. On the other hand short methods were quick and easy. Having now worked sights by hav cosine/Norie, Ageton and Norie A-K I am not so sure.
In this age of GPS and massive computing power it is difficult to put ourselves in the minds of navigators in the pre-electronic and pre-inspection table eras. Also I am writing this in armchair comfort and safety. However I would like to ask the question "Were short methods any shorter than hav cosine/Norie?"
I took my work forms for hav-cosine and Ageton and stripped out the common elements - HS correction, determination of GMT, t and dec. I then merged the two forms. See the attached pdf.
The pros of Ageton are the small physical size of the tables and the lack of interpolation. The cons (in my opinion) are that there is little if any saving in work and it is probably easier to get confused.
So, in hindsight, were short methods an improvement over the hav-cosine method?