NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Jack Aubrey's fixing of longitude
From: Hewitt Schlereth
Date: 2011 Jun 22, 10:37 -0400
From: Hewitt Schlereth
Date: 2011 Jun 22, 10:37 -0400
Well, gee, if I misconstrued Albert, I apologize. But he wrote "Lunars can be ruled out as the necessary data was not available at the
time. Regarding the lunar occultation, why should he rely on such a
seldom event?"
So, first he made a comment about non-availability of date for lunars. Then he switched to a comment about occultations.
Seemed to me he was saying Jack wouldn't try to determine the longitude by a lunar because the data wasn't available.
As to why Jack would be using another technique, I'd guess it was part of his ongoing interest in determining longitude by astronomy. Recall his struggles to make shipboard observations of occulations of the moons of Jupiter - Jack hanging in a sling and crew attempting to hold him steady.
Anyway, my apologies again to Albert if I mistook his meaning. I do think his suggestion that Jack was trying for a very accurate bearing of moon/venus set makes sense..
Hewitt
So, first he made a comment about non-availability of date for lunars. Then he switched to a comment about occultations.
Seemed to me he was saying Jack wouldn't try to determine the longitude by a lunar because the data wasn't available.
As to why Jack would be using another technique, I'd guess it was part of his ongoing interest in determining longitude by astronomy. Recall his struggles to make shipboard observations of occulations of the moons of Jupiter - Jack hanging in a sling and crew attempting to hold him steady.
Anyway, my apologies again to Albert if I mistook his meaning. I do think his suggestion that Jack was trying for a very accurate bearing of moon/venus set makes sense..
Hewitt
On Wed, Jun 22, 2011 at 10:06 AM, Dave Walden <waldendand@yahoo.com> wrote:
There is a difference between "data not available" and "lunar distances included in NA". Calculating the required lunar distances is MUCH easier than carrying out an occultation calculation.
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