question about manual setting circles
Posted 05 May 2013 - 11:09 PM
Posted 05 May 2013 - 11:22 PM
The only calculation one might make is to compensate for the 'epoch' of the published coordinates (due to earth's precession) - having a fancy HP-41 (or 67 for the even-more-ancient I suppose ) programmable calculator was the bee's knee!
Here's a google books excerpt (scroll up 2 pages for the 'easy' low-precision method) on converting epoch manually from the excellent book " Practical Astronmy with your Calculator "
Posted 06 May 2013 - 05:30 PM
manual settings circles was around a long time before computers, tables, cell phones where you can download software to tell you the exact coordinates at that time. what did they use to find the coordinates back then for the time they were viewing. donnie
We used these weird devices called "books" and "charts." Their displays were very low resolution, but they sure were easy on the batteries.
Seriously, knowing the exact epoch/coordinates was just not necessary given the low resolution of most amateur setting circles. Even in the 80s I could still use a 1950.0 atlas and manual setting circles and a great big Erfle to get objects.
Posted 06 May 2013 - 08:16 PM