NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Cross Staff in use, 1574 image
From: Wolfgang K�berer
Date: 2009 Oct 16, 23:11 +0200
From: Wolfgang K�berer
Date: 2009 Oct 16, 23:11 +0200
Brad, If you look at it closely you can see that the upper celestial body is not the sun but the moon. The picture illustrates a lunar distance as one can also find out from the text which the picture accompanies. And the picture above that illustrates horizontal parallax. As must have been mentioned numerous times before on the list, the method of lunar distances was first described by Johann Werner in 1514 in a new translation and commentary on the first book of Ptolemy's geography. All this is recounted in detail - and with the original text - in Andrewes, William, The quest for longitude, Cambridge, Mass. 1996, 376 - 385. Regards, Wolfgang --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---