A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2016 Jul 24, 22:16 -0700
"Cloudy Weather" contains log sec, log cos and half log haversine tables. The tables are four figure and involve interpolation. By rewriting the hav formula it is possible to solve a time sight without Norie. I reworked one of the time sights and the difference in logitude between the Norie and "Cloudy" calculations was 6'. Maybe if I work the sight again and take more care with the interpolation the difference will be reduced.
I did not have much luck with using the "Cloudy" tables for multiplication and division. The errors were large. The numbers involved are three digits so it would be more accurate and almost as quick to use long multiplication and division. In the explanation to the tables there are some hints which suggest that I am not using them correctly. I will need to follow it up.
In summary, if your copies of Norie, 3270, 229 and your plotting instruments have been washed overboard but you are a collector of antique books your copy of "Cloudy" will get you home.