NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
7 ways to determine longitude
From: Dan Allen
Date: 2003 Dec 24, 07:31 -0800
From: Dan Allen
Date: 2003 Dec 24, 07:31 -0800
I have just started to read an old book called "Spherical and Nautical
Astronomy", a two volume set by William Chauvenet who was a professor
at Washington University in St. Louis. My copy was printed in 1903 but
it appears that it is just a reprint of an 1863 edition.
Chapter 7 is "Finding Longitude by Astronomical Observation" where it
lists seven different methods, which are:
"1st method - by portable chronometers
2nd method - by signals
3rd method - by the electric telegraph
4th method - by moon culminations
5th method - by azimuths of the moon, or transits of the moon
and a star over the same vertical circle
6th method - by altitudes of the moon
7th method - by lunar distances"
By chronometers it means chronometric expeditions: taking a chronometer
from Greenwich to Boston and comparing mean noon times. By signals it
includes eclipses, occultations of Jupiter's moons, and terrestrial
signals.
Interesting.
Dan
