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Subject: Re: Carry on, Mr. Bowditch
From: John McKeel (jgmckeel-250927) (jgmckeel@XXX.XXX)
Date: Thu Jan 16 2003 - 10:57:31 EST
Dear Jan,
Thank you for your very clear contributions. It would be helpful to me (and
to others on the list I'm sure) if we had the links to all four of George's
postings on lunars.
Thanks in advance!
John McKeel
Phoenix, AZ
-----Original Message-----
From: Jan Kalivoda [mailto:jan.kalivoda@XXX.XXX]
Sent: Thursday, January 16, 2003 2:16 AM
To: NAVIGATION-L@XXX.XXX
Subject: Re: Carry on, Mr. Bowditch
Dear David,
let me try to answer your questions one by one.
It is absolute nonsense that before Bowditch, the lunars were useful to
seamen only in the moments of a star occultation by Moon. In contrast,
occultations were never used for navigational purposes at sea. The only
theoretical reason for using a sextant for observing occultations is its
telescope - but to use a the stand-alone one would be more simple. In this
point the Bowditch story you have cited is quite unreliable and ridiculous.
You must hope that in other things it is correct, but ... (I didn't read
it.)
The assertion that only Bowditch's method made the use of lunars possible
for ordinary seamen is motivated by the national pride a bit. Of course, it
is claimed in all editions of American Practical Navigator I have known. It
is only matter of taste and nationality.
If you search for a clear and precise explanation of lunars, take the text
of George Huxtable (in four parts) that has been published in this list as
the best. If you want, I can send it to you privately. A bit of spherical
astronomy and trigonometry is necessary for understanding it, of course. If
some elucidation without any computations and formulas is wanted in this
list, I can try it.
A trial for a summary of relations between lunars and chronometer methods
during the past (including the impact of chronometer prices) was sent to
this group by me - I excuse me for referring to myself:
http://www.irbs.com/lists/navigation/0301/0054.html
Yours, Jan Kalivoda
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