NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Chasing tenths of an arc minute
From: George Huxtable
Date: 2010 Mar 12, 22:48 -0000
From: George Huxtable
Date: 2010 Mar 12, 22:48 -0000
Yes, the National Maritime Museum at Greenwich has altogether around 16 various mariners' sextants by Ramsden, but as far as I know every one is a Vernier type. If Richard knows better, I would be most interested to learn about it. George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ----- Original Message ----- From: "Richard Reed"To: Sent: Friday, March 12, 2010 9:44 PM Subject: [NavList] Re: Chasing tenths of an arc minute NMM has another Ramsden from 1783. This one has 305 mm radius, one scope, and looks to be a nautical instrument with a wooden handle, but I'm not sure whether it caught on. In any case, it has nothing to do with the 20th-century innovation of precision arc hobbing. ---------------------------------------------------------------- NavList message boards and member settings: www.fer3.com/NavList Members may optionally receive posts by email. To cancel email delivery, send a message to NoMail[at]fer3.com ----------------------------------------------------------------