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Thanks, Frank, for your usually thorough exegesis. As it happens the
only edition of Bowditch I still have is the 1933. I've hung onto it
because of the table of lunitidal intervals and coordinates of
stations all over the world.

I will check out the site. I once had a 1917 edition of Bowditch but
don't recall lunars being it. My acquaintance with time sights is
Philip Weems' Line of Position Book which I used to carry as a backup
till I conned an unsuspecting publisher into Sight Reduction Tables
for Small Boat Navigation. :-)

Hewitt

BTW if Moby Dick wasn't the whale, who or what was it (he, she)?

On 2/5/09, frankreed@historicalatlas.com  wrote:
>
>  Hewitt, you wrote:
>  "Could the phrase "working lunars" mean they were working through the
>  night - by the light (of the silvery light) of the moon?  :-)"
>
>
> Heh. I know you're kidding, but as long as you bring it up, they seem to 
have used the expression 'working lunars' in a specific way --it meant doing 
the calculations for lunars-- while 'taking lunars' referred to the 
observations. If you're searching through old sources and logbooks 
especially, keep an eye out for variants with 'luners' (with an 'e') since it 
was often spelled that way in the early period.
>
>
>  You also wrote:
>  "Less facetiously, I ask because you indicated the log said the "crew" were 
working lunars and my notion of whaleship crews at that time is that they 
weren't math-heavy."
>
>
> The math for lunars is no more difficult than the math for a time sight (the 
calculation of local time from an observation of the Sun or a star when it 
bears nearly east or west) and time sights were worked every day. The 
difference with lunars was that there was a preliminary calculation, the 
"pre-clearing" steps, a final interpolation step (where the reduced lunar 
distance observation is compared with the almanac data) and also the 
trigonometric part was very similar to working two time sights. So all told, 
the calculation was three to four times longer than a standard time sight. I 
would emphasize that this was only longer, more tedious work... not more 
difficult than a time sight. The reputation that lunars were devilishly 
difficult mathematically began at the beginning of the lunars era, when 
simple methods had not yet been developed, faded when they were actually in 
common use at sea, and then returned at the very end of the lunars era, when 
long methods made a comeback for a variety of reasons.
>
>  And you added:
>
> "I seem to recall hearing that Bowditch began American Practical Navigator with basic arithmetic."
>
>
> Yes, and in this he was just copying Moore and other authors of navigation 
manuals who came before him. I don't know how many people actually learned 
basic math from Bowditch's Navigator, but they could if they had to. And me, 
too -- I'm sure I'm not the only one in this group who first learned a little 
something about trigonometry and calculus in the pages of a dusty Bowditch 
found on a shelf.
>
>  From the way you've worded your comment above, I wonder if you're aware 
that there are now quite a few editions of Bowditch from the 19th and early 
20th centuries available online (and of course the current edition). I 
assembled a list of these, and other historical navigation resources 
available online, following the Navigation Weekend at Mystic Seaport last 
June. It's located here: http://www.fer3.com/Mystic2008/navbooks1.html.
>
>  -FER
>  www.HistoricalAtlas.com/lunars
>
>
>
>
>  >
>

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