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From: Fred Hebard (no email)
Date: Wed Jun 01 2005 - 09:52:41 EDT
In reading the Wikipedia entry on celestial navigation, I came across
the following statement:
"Traditionally, a navigator set his chronometer from his sextant, at a
geographic marker surveyed by a professional astronomer. This is now a
rare skill, and most harbor masters cannot locate their harbor's
marker."
A few years ago, in discussing a late 19th-century book about repair of
submarine telecommunications cables, I asked why the captain and first
mate went ashore to do time sights, when the could have gotten time
from the cable. I suppose the answer was that time wasn't sent over
the cable that often, not to mention that it might have been broken
when they were in harbor. At any rate, this is the first mention I
have of people setting their chronometer from a precisely measured
location. Previously, I had gather from this list that the captain and
first mate were rating their chronometer, not setting its absolute
time. It appears they were setting it, and perhaps also rating it.
Is there any mention of this in the older texts, such as Chauvenet,
where time sights were done at geographic markers set by a professional
astronomer?
Thanks,
Fred
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