NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: accuracy of Cook's lunars
From: John Huth
Date: 2012 Dec 31, 17:07 -0500
From: John Huth
Date: 2012 Dec 31, 17:07 -0500
Here's what the student related to me about her methodology:
The coordinate were taken Cook's journals from the first expedition. There are many editions available, but I find these two the most accessible and reliable: Hawkeworth's 1773 first edition, and a later 1893 transcription. Of the two, the 1893 transcription is easier to read (no more 18th century "f"-looking "s"s!), and also more accurate--the 1773 first edition had several typos that gave me huge errors in Cook's longitudes. 18th century maps on the expedition can be found, in high resolution, at this Princeton site.
If I had more time, I'd definitely have double checked Cook's measurements against NASA's historical lunar cycles to make sure measurements from dead reckoning didn't sneak into the data (for my project I kind of trusted Cook to clarify his methodology--but I know it isn't good statistical practice.) The NASA moon phases for the 18th century can be found here.
Also, if you're interested in the comparative reliability of chronometers vs. the lunar method, Cook's later two voyages are really fantastic for this topic. In his journal of the second voyage, there's even a table on chronometers (they called them "time-keepers") and the observed rate at which they lost accuracy over time at sea. George Vancouver's journal from his 1790-95 expedition to the Norther American Pacific coast is also great.
Thank you so much for taking interest in my project. Despite the time crunch, I had so much fun working on it, and your class this past semester was a joy for an "intimidated-by-science" humanities major like me.
If I had more time, I'd definitely have double checked Cook's measurements against NASA's historical lunar cycles to make sure measurements from dead reckoning didn't sneak into the data (for my project I kind of trusted Cook to clarify his methodology--but I know it isn't good statistical practice.) The NASA moon phases for the 18th century can be found here.
Also, if you're interested in the comparative reliability of chronometers vs. the lunar method, Cook's later two voyages are really fantastic for this topic. In his journal of the second voyage, there's even a table on chronometers (they called them "time-keepers") and the observed rate at which they lost accuracy over time at sea. George Vancouver's journal from his 1790-95 expedition to the Norther American Pacific coast is also great.
Thank you so much for taking interest in my project. Despite the time crunch, I had so much fun working on it, and your class this past semester was a joy for an "intimidated-by-science" humanities major like me.
