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Re: Can someone identify this
From: George Huxtable
Date: 2008 Nov 11, 22:29 -0000
From: George Huxtable
Date: 2008 Nov 11, 22:29 -0000
Bruce Hamilton asked- "Anyone need something for their collection? What exactly is it? http://cgi.ebay.ca/ASTRONOMIC-CALCULATOR-SEXTANT-theodolite_W0QQitemZ190265697439QQcmdZViewItem?hash=item190265697439&_trksid=p3286.c0.m14&_trkparms=72%3A1215%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318"|==================It's a Zerbee "Fix Finder". Perhaps it's THE Zerbee Fix Finder. described inthe US patent 2519532 , attached. It could be the prototype, perhaps theone-and-only, because it's labelled serial number 1; the invention of LouisB Zerbee, patent granted 1950. You can dial up the details in GooglePatents.I've never seen one or even heard of it before. It claims to be able tosolve one OR MORE spherical triangles, simultaneously, so could presumablyresult in a fix from a pair of star altitudes. I admit to not having studiedthe details of the patent in any detail. These things are written in aspecial arcane language that seems intended to obscure more than it reveals.It seems to be a development of the armillary sphere, an analoguerepresentation of the Earth and sky, allowing spherical triangles to besolved. Such armillary spheres first appeared in China in the first-centuryBC. The nearest thing to this device I've seen (in print) is the Mariner'sCalculator, in Janet Taylor's "Navigation simplified" of 1849, but thatcould solve only one spherical triangle at a time.But this one is FAR more sophisticated. Just look at the profusion of arcscales, each fitted with its own micrometer readout. No expense has beenspared in its construction; which may be why it wasn't developed further. Itwould be interesting to discover what accuracy was achievable.It's the sort of instrument I would love to own. You could play with it forhours. I expect it will fetch a lot more than the present bid, and shouldreally find a home in a museum. Perhaps a Museum of Complication, if such aspeciality exists.George.contact George Huxtable, now at george@hux.me.ukor at +44 1865 820222 (from UK, 01865 820222)or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To unsubscribe, email NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~---