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Re: ? ? ? Re: Lewis & Clark
From: Bruce Stark
Date: 2004 May 26, 15:57 EDT
From: Bruce Stark
Date: 2004 May 26, 15:57 EDT
Ken,
You say you think Jefferson's advice (that Lewis not bother with the calculations) was seriously in error. Before reading your posting I wouldn't have been able to take that idea seriously. But you have presented a powerful argument. I'm convinced you are right.
Your posting has a good deal else of interest and value, which I hope to get to later.
The only part I can't understand is where you say " . . . takes only 6 or 7 and does the
long division). They use these values to determine the true distance
for that particular time (this is the D value that Thompson writes
down in his notebook; it is not the cleared distance as assumed by
Jeff Gottfred in his Northwest Journal article). They clear the
distance (using Witchell's method) and then use the difference
between their cleared distance and the true distance to update their
longitude by account."
In my mind the average of the sextant distances is not the true distance. The cleared distance is. Also, I'd like more explanation of ". . .use the difference between their cleared distance and the true distance to . . ."
Everything else you say fits exactly with my notions of how the old nautical astronomy worked.
Bruce
You say you think Jefferson's advice (that Lewis not bother with the calculations) was seriously in error. Before reading your posting I wouldn't have been able to take that idea seriously. But you have presented a powerful argument. I'm convinced you are right.
Your posting has a good deal else of interest and value, which I hope to get to later.
The only part I can't understand is where you say " . . . takes only 6 or 7 and does the
long division). They use these values to determine the true distance
for that particular time (this is the D value that Thompson writes
down in his notebook; it is not the cleared distance as assumed by
Jeff Gottfred in his Northwest Journal article). They clear the
distance (using Witchell's method) and then use the difference
between their cleared distance and the true distance to update their
longitude by account."
In my mind the average of the sextant distances is not the true distance. The cleared distance is. Also, I'd like more explanation of ". . .use the difference between their cleared distance and the true distance to . . ."
Everything else you say fits exactly with my notions of how the old nautical astronomy worked.
Bruce
