Next message: Frank Reed: "Re: How good were chronometers?"
On 15 Mar 2006 at 8:38, wrote:
> Frank,
> You wrote:
>
> > Stars, including Polaris, were rarely used in celestial navigation >
> before the 20th century except occasionally for lunar distance
> sights.
>
> I seem to recall reading in a number of places that they were especialy on
> land. Hard to say what is right when you here so many different things!
The fur trade navigators in North America used stars extensively for
lunars in the late 18th and early 19th centuries. There may be several
reasons for this. It would be inconvenient to stop the brigade for
observations (even the noon sight is not done that regularly), using stars
would allow a time sight that used a star that was rising or setting (they
always take a time sight just before or after their lunar), in the
Northern winter the opportunities for star-lunars are better and more
frequent, probably there are other reasons as well that don't come to mind
at the moment.
\----------------------------+---------------------------------+ o_,
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"\ L | University of Calgary | | / /
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Morning coffee recapitulate phylogeny L/
