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    Re: Sextant and quintant limits
    From: Richard M Pisko
    Date: 2008 Dec 25, 23:31 -0700

    On Sat, 20 Dec 2008 12:33:05 -0700, George Huxtable   
    >  "Douglas reflecting protractor". (Note, this shouldn't be
    > confused with the modern Douglas Protractor, a transparent marked-off
    > square). It was the invention of Sir Charles Douglas, an army man, who  
    > got a
    > British patent for it (3461 of 1811). I haven't discovered if there's a  
    > way
    > to access UK patents without visiting the British Library, so if anyone
    > knows how to do that, that would be of interest.
    Actually, I believe Sir Howard Douglas, son of Admiral Charles Douglas was  
    the inventor.  The oldest hall at the Royal Military College is named  
    after him.
    At any rate, another interesting reference that *may* be closer to your  
    independent invention is to be found by a Google Book search for  
    "Reflecting Sector" in Philosophical Magazine, of around 1822, pages 301  
    to about 310.  Unfortunately, there are no drawings to correspond with the  
    description of the device by Professor Amici of Modena; but I have seen  
    something that might match in other image searches for "reflecting sector"  
    and "Amici".
    The device operates over a range of 180 degrees, uses triangular and  
    rectangular prisms; and does sound interesting.
    Unfortunately, I had to use Internet Explorer to get the pages below;  
    Opera didn't work.
    Richard . . .
    Using Opera 9.2.4 after the "Dog" died
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