NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: sextant precision.
From: George Huxtable
Date: 2005 Jun 23, 10:37 +0100
From: George Huxtable
Date: 2005 Jun 23, 10:37 +0100
In an old Brown's Almanac (for 1988) there's an advertisement for B. Cooke & Son Ltd, Kingston Observatory, 58/59 Market Place, Hull, England. Opposite the page showing their Cooke "Kingston" Micrometer Sextant is a description and photo of the "Cooke" Plath precision Collimator, about which the text says- "Reading to one second of arc is used in the final testing of our Kingston Sextant. A reliable sextant continues to be the one indispensable instrument of the navigator. The quality of the instrument is dependent on the skill of the craftsmen, instrument makers and opticians alike, sharing in the task of reaching perfectrion. Navigators generally, have little knowledge of Sextant Manufacturers' testing devices, which have been developed until, at last, the perfect instrument is in being. We cordially invite any navigator, when in Hull, to bring his sextant to our factory and see it tested on this precision instrument." The photo shows a very glossy device, but is a bit inscrutable, in that I can't even work out where the sextant goes. But if anyone is interested, I'm happy to scan it and send a copy to anyone who asks. Cooke's are still in business; they supply my wife with weekly Admiralty "Notices to mariners" from which she keeps our charts up-to-date. I phoned them to ask if they still calibrated sextants, and indeed they do. I spoke to Harry, who told me that he was long-retired, but was called in when they had a sextant job to do, so happened to be there that day. He also told me there was a limited stock of replacement parts for sextants, and that resilvering could be done. The sting in the tail came when I was transferred to the office to tell me their prices. I was told to expect a bill of ?160 to ?200, depending on what work was needed. I think that ?1 corresponds to about $1.85 at present. Cooke's email address is bcs@cooke.karoo.co.uk, their phone number is 01482 223454 or from abroad +44 1482 223454. They don't have a website. George. =============================================================== Contact George at george@huxtable.u-net.com ,or by phone +44 1865 820222, or from within UK 01865 820222. Or by post- George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.