Two On A Big Ocean The Story of the First Circumnavigation
of the Pacific Basin
in a Small Sailing Ship


      

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Hal Roth
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Re: Calculated Altitudes for Lunars


Subject: Re: Calculated Altitudes for Lunars
From: Bruce Stark (Stark4677@XXX.XXX)
Date: Sat Oct 26 2002 - 21:01:44 EDT


To the best of my knowledge, George, Bill, Herbert and I are in complete
agreement on three points:

(1) Calculated altitudes are perfectly acceptable for clearing lunar
distances.

(2) One calculation does it for most practical work, as long as you go about
it the right way.

(3) The procedures I've posted for calculating altitudes are not new. They
are essentially the same as the one used from the 1760s on up to the last
half of the nineteenth century.

As I see it, Herbert's comments on George's and Bill's recent postings have
nothing to do with this; they have to do with whether or not Bill and George
understand how the elements of the problem fit together. If you read only the
excerpts he's taken, and taken exception to, you can understand his concern.
But I believe if you put those excerpts back where they came from and read
them in context you'll see that George and Bill do, in fact, understand how
the elements fit.

This has been a good thread, and it may lead into another good one.

Someone (was it Henry Ford?) is supposed to have said "History is bunk."
Given the present state of the history of navigation, I find that hard to
dispute.

George pointed out a while back that in order to understand what the old
navigators were doing, and why, you have to understand their mindset. In
another posting he mentioned that Cotter skated around a question having to
do with the way the old navigators worked with time and longitude. I read a
good bit of Cotter's A History of Nautical Astronomy a decade or so ago, and
learned a lot. But I did get the impression he hadn't fully grasped the old
view of time, and thus the logic holding the system together.

If Dava Sobel or her advisors had understood the navigation of those days,
and why it had to be the way it was, her book wouldn't have been constructed
on the framework of a trite dramatic device.

Bruce





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