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    Re: Old style lunar
    From: Fred Hebard
    Date: 2004 Dec 10, 14:51 -0500

    On Dec 10, 2004, at 1:02 PM, Ken Muldrew wrote:
    
    > On 10 Dec 2004 at 8:48, Fred Hebard wrote:
    >
    >> Regarding those inaccuracies, it would be helpful to see the entire
    >> series of observations for each of the lunars.
    >
    > I only have a couple of these already transcribed (I'm working from
    > digital photographs of microfilm--it can be very difficult to make out
    > some of Thompson's writing). I'll include a couple of other runs that 
    > were
    > near Rocky Mountain House (but since he was on the trail I don't have a
    > true position for the resulting longitude--I include them only as 
    > typical
    > examples of his observation).
    >
    > Feb. 24 1801 Regulus
    > 9:48:38  30?36'30"
    > 9:49:32  30?36'00"
    > 9:50:23  30?35'50"
    > 9:51:13  30?35'15"
    > 9:52:07  30?34'45"
    > 9:52:55  30?34'30"
    >
    > Feb. 24 1801  Aldebaran
    > 9:55:31  57?19'45"
    > 9:56:38  57?20'00"
    > 9:57:36  57?20'30"
    > 9:58:28  57?21'00"
    > 9:59:16  57?21'15"
    > 10:00:07  57?21'45"
    > 10:00:56  57?22'00"
    > 10:01:48  57?22'15"
    >
    > Nov. 26, 1800 - Aquilae (Altair)
    > 8:53:05  81?17'45"
    > 8:53:55  81?17'45"
    > 8:54:38  81?18'00"
    > 8:55:20  81?18'30"
    > 8:56:00  81?18'45"
    > 8:56:52  81?19'30"
    > 8:57:38  81?19'15"
    > 8:58:29  81?19'30"
    >
    > Nov. 26, 1800 - Aldebaran
    > 9:01:43  49?5'45"
    > 9:02:52  49?5'15"
    > 9:03:20  49?5'00"
    > 9:04:15  49?4'45"
    > 9:05:12  49?4'15"
    > 9:06:10  49?4'00"
    > 9:07:08  49?3'45"
    > 9:07:58  49?3'15"
    >
    > I don't know if you can conclude much about Thompson's skill from these
    > runs. They look pretty smooth to me when I plot them.
    >
    > Nowhere in Thompson's notebooks do we ever find any of his 
    > calculations,
    > so we can't say whether errors crept in during the reduction phase (in 
    > my
    > own limited experience, I often get the last couple of decimal places 
    > of
    > tabled log values wrong by adding the corrections in my head and 
    > losing a
    > place between the table and when I write the value down). Although of 
    > the
    > sights that I have checked, the corrections he writes down are exactly 
    > the
    > same as I get using Witchell's method so I think his calculations were
    > probably OK.
    >
    > Ken Muldrew.
    
    Here are some pictures of these data, without reduction.  None of these 
    lunars are as good as that one of Gregory's posted by Kieran Kelly, but 
    that might have been one of Gregory's better ones (well, it had to be, 
    I can't see them getting much better than that).  These ones of 
    Thompson's are very good, with the exception of the Altair shot.  I 
    would guess that Thompson is not off by more than 0.2 or 0.3' of arc in 
    the distance on these, depending upon how he picked his value to be 
    reduced.  These also are paired observations so should be reduced in 
    tandem.
    
    By the way for others more scrupulous than myself, I haven't been 
    yelled at thus far for posting small binaries like these.
    
    Fred
    
    
    
    
    
    

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