NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Possible limitaion for lunar distance measurement
From: Frank Reed
Date: 2009 Mar 2, 14:58 -0800
From: Frank Reed
Date: 2009 Mar 2, 14:58 -0800
George H, you wrote: "But it's news to me that Dunthorne's procedure (one of the very earliest for clearing the lunar distance, and included in Maskelyne's first "Tables requisite" in 1766) is defective in that way." Well, of course, it is not defective in this way. Dunthorne's formula is identical (in the mathematical sense) to any of the direct triangle solutions of the problem of clearing a lunar distance. I have now found a copy of this 1906 Lehrbuch der Navigation on Google Books (and therefore, everyone, please ignore my previous request for scanned pages). This link should take you right to the page in question: http://books.google.com/books?pg=PA385&id=cjtLAAAAMAAJ My German is mediocre, but I cannot find any explanation at all for this supposed limitation in Dunthorne's formula in the text. I think the author of this passage may simply have been mistaken. The only other possibility that I can think of is that the alternative formula proposed works better with five-figure log tables. Anyone care to try that out? -FER --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---