A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Robin Stuart
Date: 2020 Jan 8, 09:25 -0800
When I saw that March’s edition of Sky & Telescope contained an article entitled Captain Cook’s Astronomy, I knew it would prove fertile ground for nitpicking. Here are a couple of things
For his first voyage Cook used lunar distances as his primary method for determining Greenwich Time. He measured the angular distance between the Moon and the Sun or reference star with a sextant, and recorded the local time. He consulted the British Nautical Almanac to determine at what time the angular distance would be the same if observed from Greenwich.
I think he would probably have found it easier just to determine the geocentric angular distance.
Maskelyne also evaluated the contenders for the Longitude Prize, and his bias for using lunar distances delayed the acceptance of John Harrison’s H4 chronometer as the best method for determining longitude at sea.
This propagates a baseless and tragic popular myth about the great man.
The author is Ted Rafferty who it notes worked at the USNO for 32 years.