NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant manufacturers
From: Michael Daly
Date: 2007 Oct 25, 17:47 -0400
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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