A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2016 May 15, 18:20 -0700
First of all, thanks for the link - Scrap Paper.
Second, about logarithms. The logs of sin and cos are negative so the old navs added 10 to make positive numbers. Still you were dealing with a decimel point and had to rember to drop the the 20s and 30s etc. Why do you think the method of multplying by -100,000 was not used instead?
Greg Rudzinski posted a sin, cos, log table that is very easy to use. I have done sight reductions from the old Bowditch and other old texbooks and the -100,000 log table seems SO EASY compared to the +10 tables. Do you know if anyone used simalar tables in the 19th C. or had no one thought of it? I find that doing time sights with the sin, cos, log ( times -100,000) is fun.
I have learned to love logarithms.