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Frank,
   Thanks for the recommendation to read "Yankee Stargazer".   I will
try to find a copy in one of my libraries and read it.   Let me respond
to your question about what aspect of almanac construction interests
me.....

    I am not looking for the "best modern methods".  I'd like to know
more about how Bowditch, and his contemporaries (but also his 18th
century and 17th century predecessors) put together their almanacs
(other than copying other peoples works).  It would be helpful to know
how to put together my own using "semi-traditional" or even
"traditional" methods.

A related interest is possibly not directly related to the writing of
almanacs, but then again perhaps it is.   The celestial navigation of
the day seems to involve a lot of looking things up in elaborate
tables, but I'm trying to better understand how those tables were put
together in the first place, that is ... what is their mathematical
derivation?


I've been working with an 1830 edition of Bowditch for a while, looking
at his various methods for clearing the lunar distance, and I'm not
really getting what the tables for "1st correction" "2nd correction",
etc are doing, or exactly his algorithm for combining the many tabular
values works.

I am slowly translating de Mendoza y Rios' 1797 presentation to the
Royal Society on lunars and it has been helpful.  I found a web site
which linked to another site which gave a complete (100 pages or so)
scanned image of the presentation as reported in the Philosophical
Transactions.  Fortunately I printed out a paper copy of the entire
presentation [although I could only get it one page at a time], because
I can not remember where I found this site and have been uable to
locate it again using Google, etc.

I am also trying to decipher what Cotter has to say in his "History of
Nautical Astronomy".  It seems to me that there are more than a few
errors in this book and much that is incompletely explained, but
perhaps I just haven't spent enough time studying it.




FrankReedCT@aol.com wrote:
> "Can anyone on the list direct me to some (simple?) sources that  would
> describe how one would go about making his or her own  almanac.   I just
> finished reading a fictional biography of  Nathaniel Bowditch called
> "carry on Mr Bowditch" that was written for young  adults in the 1950's.
> The author has the 14 year old Bowditch "writing his  own almanac" .
> Whether or not this actually happened, I am curious as to how  one would
> approach this task."
>
> Can you elaborate on which aspect of this interests you? Do you want to  know
> how Bowditch and contemporaries might have assembled an almanac? Do you  want
> to make your own almanac using semi-traditional methods? Do you want  to make
> your own almanac using the best modern methods? Or something else  entirely.
>
> By the way, the book "Carry on Mr. Bowditch" is a great read but it  contains
> numerous factual inaccuracies. Most importantly, the whole "eureka"  moment
> about lunars and measuring three stars and all that and the very idea  that
> Bowditch somehow revolutionized the lunar distance method is just plain  hogwash
> (she was repeating and then magnifying a common mis-statement). That  said,
> yes, it's true that young Bowditch made his own almanac. But this is  partly a
> game of smoke and mirrors. Tools were available in the era that would  enable
> any industrious person to publish his or her own almanac localized for  the
> observer's location. A comparable modern task would be porting an  open-source
> software product to a new platform. It looks difficult if you don't  know
> anything about it. You can imagine a teen today being declared a  genius for porting
> a piece of software to his cell phone --if the people seeing  the result know
> nothing about software development. Yes, it's a nice  project that requires
> attention and hard work but no more than  that. Creating his own almanac in
> Bowditch's era shows, above all, the  creative power of innocence. Bowditch
> didn't know that he was too young  to make his own almanac by any reasonable
> measure, so he did it  anyway.
>
> Finally, if you would like to read a real biography of Nathaniel Bowditch,
> get a copy of "Yankee Stargazer" by Berry. It's good. There are several others,
>  all fairly bad.
>
> -FER
> 42.0N  87.7W, or 41.4N  72.1W.
> www.HistoricalAtlas.com/lunars
>
> ------------------------------



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