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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Old style lunar (in expert hands)
From: Frank Reed CT
Date: 2004 Dec 10, 22:06 EST
From: Frank Reed CT
Date: 2004 Dec 10, 22:06 EST
Kieran Kelly, you wrote:
"Also on this topic Frank Reed wrote: "But something that might not
be so
obvious is that dead reckoning is simpler at sea since it consisted of long
legs on constant headings. At least there aren't any currents on land!"
I have used both horses and camels in desert conditions without landmarks
following a compass bearing. Dead reckoning is easy under these conditions"
obvious is that dead reckoning is simpler at sea since it consisted of long
legs on constant headings. At least there aren't any currents on land!"
I have used both horses and camels in desert conditions without landmarks
following a compass bearing. Dead reckoning is easy under these conditions"
Good point! DR is easier in a desert than on the open sea. Most land
environments don't allow the explorer to travel on constant courses, however,
making DR much messier.
By the way, for that lunar on August 4, 1856, the predicted lunar distance
you quote from the contemporary Nautical Almanac was 29..36..19. Using modern
almanac data, the predicted distance at that time should have been 29..36..56.
If I've followed this through correctly, that means the implied longitude is
136..11..45 which brings Gregory's lunars even closer to the correct
longitude.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
[ ] Mystic, Connecticut
[X] Chicago, Illinois
