NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Paul Quincey
Date: 2026 Jul 10, 12:33 -0700
I think you are spot on.
James Cook knew the latitude and longitude for his first destination, Tahiti, because they had been established in 1767 by John Harrison (no relation), on board Samuel Wallis's ship the Dolphin. Harrison did not have a Nautical Almanac, but had used the Lunar Distance method set out in the British Mariner's Guide published in 1763. It would have been extraordinary if Charles Green or Cook had not brought a copy of it, and learnt how to use it, as they knew their voyage might last longer than their Almanacs.
There is a nice quotation in Richard Dunn and Rebekah Higgitt's book "Ships, Clocks and Stars" (p.129): "Wallis said it was done by 'taking the distance of the Sun from the Moon and working it according to Dr Masculine's Method which we did not understand.'"
