A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Lars Bergman
Date: 2018 Dec 17, 08:47 -0800
Your favorite 19th century blogger has a typo in the half sum of logs. Also, he neglects to interpolate in the four-seconds-of-time-interval in his table; the resulting longitude is thus somewhat off. Presumably he used Bowditch or some other table with a similar set-up, showing "double time" along the log sine column. With most other tables I have seen, you have to multiply the half hour angle with two in order to get the correct hour angle. Just an observation.
Lars 59°N 18°E