NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sumner lines
From: George Huxtable
Date: 2001 Feb 17, 5:08 PM
From: George Huxtable
Date: 2001 Feb 17, 5:08 PM
Peter Smith wrote- >Apropos the current discussions of ex-meridian sights and books on the >longitude problem... > >Can anyone recommend any articles, books, or parts thereof that chronicle >the gradual change in common practice from separate solutions for latidude >and longitude to LOP-based methods, first Sumner's, then altitude-intercept >after Saint Hillaire? Neither _From Sails to Satellites_ nor _The >Haven-Finding Art_ cover this. All I have been able to gleen is inferences >from the way the topics are treated in various editions of Bowditch. It >would seem that the US Navy adopted the new methods early in the 20th >century, but the merchant marine continued with the old right up to WW-II. > > -- Peter =================== Yes, the book you're looking for is definitely Charles H Cotter, History of Nautical Astronomy, Hollis & Carter, London, 1968. Chapter 6, Methods of finding longitude, and 7, Position-line navigation, together make up nearly half of a 400-page book. So you will find all the detail you need, and maybe more than you bargained for. With masses of stuff on lunars, if that interests you. Not easy reading though: Cotter knows his trigonometry, and doesn't stint on the maths. I find it very thorough and satisfying, though Steven Wepster in a recent mailing was less impressed. Not easy to find, though. I had a search out for it for several months on a couple of websites for secondhand books. Eventually it appeared on Abe books at US$100. Of course, the way these things go, just after I had bought it a second copy turned up at less than half that price! It was several months ago now, but that copy may still be available. Try a search on Abe books. Good luck. George Huxtable. ------------------------------ george@huxtable.u-net.com George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. Tel. 01865 820222 or (int.) +44 1865 820222. ------------------------------