A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Nov 19, 07:36 -0800
The Doniol formula at the bottom of the sin cosine table would be better listed as:
Sin Hc = n-(n+m)a
n= cos(L-d) , m= cos(L+d) same name
n= cos(L+d) , m= cos(L-d) contrary name
When doing the reduction in the two column format p= the product value of column A where p= (n+m)a which speeds the reduction and saves space on the index card.