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Subject: Re: Classification of the methods for clearing the Lunar Distances
From: Fred Hebard (Fred@XXX.XXX)
Date: Thu Apr 10 2003 - 20:20:15 EDT
Bruce,
Perhaps my summary of Bowditch was inaccurate rather than the work
itself.
It said:
"Davis' Requisite Tables, published in London in 1905, introduced the
cosine-haversine FORMULA [emphasis mine] to navigation, although it had
been used previously by astronomers. This formula is
hav(z) = hav(L~d) + cos(L)cos(d)hav(t),
in which z is zenith distance (90-h). This is sometimes written
hav(z) = hav(L~d) + hav(theta),
in which hav(theta) = cos(L)cos(d)hav(t)."
A few pages earlier, Bowditch mentions that, "Early tables for
solutions of meridian angle were called horary tables."
I must add, in the same spirit as Herbert Prinz, that I much admire
your work.
Fred
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