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    Re: Sextant manufacturers
    From: Michael Daly
    Date: 2007 Oct 25, 17:47 -0400

    Alexandre E Eremenko wrote:
    >
    > Perhaps a list of dividing engins would be shorter
    > (and more interesting) than a list of "makers":-)
    > But harder to make.
    
    duc de Chaulnes, 1768
    Ramsden, 1773  first significant "public domain" design
               (by virtue of Crown financing)
    Troughton E., 1778 (based on Ramsden's but improved accuracy)
    Lenoir, 1783
    etc.
    
    I put this stuff on Wikipedia on the "Dividing engine" article but would
    like to carry it forward a bit into the 19th c.
    
    One thing I'd love to find is a graph I remember seeing in a
    book/article about 20 years ago.  It showed the improvements in accuracy
    of dividing engines over time.  It started with John Bird and ended in
    the 19th C, IIRC.  (Bird didn't use an engine but a series of beam
    dividers etc).  If anyone knows where such a graph is, please let me know.
    
    Mike
    
    
    
    
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