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About Bayly's page of lunar distance observations-

If anyone intends to investigate this data seriously (and to me, that seems 
well worth doing), he should look at a copy of the 1773 Nautical Almanac, 
to be found in Google Books at-


http://books.google.com/books?id=0fYNAAAAQAAJ&printsec=frontcover&dq=intitle:nautical+intitle:almanac+intitle:and+intitle:astronomical+intitle:ephemeris&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&as_brr=1&cd=4#v=twopage&q=&f=false

Sorry about the long link. If anyone has difficulty in getting access, I've 
downloaded the whole thing as an 11 megabyte .pdf, and will be hapy to send 
a copy to anyone interested.

Using those almanac pages, you can't get more authentic; these were the 
very pages that Wales, and Bayly, were working from, at the time.

To view the tables on the website, it's useful to choose the 
two-pages-in-one view, as the tables tend to spill across pairs of facing 
pages.

The relevant pages of lunars for August 1773 are 92-93 for objects East of 
the Moon, and 94-95 for those West. You can see that Sun lunars weren't 
predicted until 7th August, when the distance reduced to 120º, so Bayly was 
getting in, several extra days earlier, for free before that. He seems to 
have taken a LOT of trouble, in order to avoid having to take a star lunar 
instead, which tends to back Frank Reed's view about the unpopularity of 
star lunars.

Sun semidiameter can be found on page 89, Moon's semidiameter and parallax 
on page 91.

If local time is to be determined from Sun position, Sun coordinates are on 
page 86, but in RA instead of the familiar (to us) GHA. Equation of time is 
there also.

I'll comment on Brad's recent investigation in another posting.

George.

contact George Huxtable, at  george@hux.me.uk
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. 

   

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