A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2016 May 3, 13:29 -0700
I think that Lewis & Clark have be badmouthed over the years for poor sextant skills but I think that it is not deserved. Pres. Jefferson instructed them to record and bring back the cel-nav data to Washington and a math person would do the sight reductions.
Before going West the two explorers were given a quick cel-nav course by Robert Patterson and Andrew Ellicott. Patterson had developed a method of Lunars where you do not need to measure the altitude of the moon and the star or sun. His method #4 calculated the altitudes from an asumed lat & long. He thought this was easier for land explorers because they would not have to set up the mecury artifical horizon when doing a luner.
When Lewis and Clark got back to Washington their data wa given to Ferdinand Hassler, a professor at West Point. Hassler could not do the lunars thinking information was missing and declared that the two explorers messed up. Hassler apperentarly did not know Patterson's methiod #4.
In recent years a man naned Robert Bergantino used the log books of L & C and used method #4 and calculated Lat and Long for the expidation. He said the data was very close to the moderen values.
A Richard S. Preston of N. Illinois U. has written an excellent paper on the Lewis & Clark sextant data. The paper can be found on the internet.