NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: How Worsley Navigated [Was Navigation and Whaling]
From: Brad Morris
Date: 2009 Feb 23, 10:35 -0800
From: Brad Morris
Date: 2009 Feb 23, 10:35 -0800
Hi Frank It is important to differentiate between various portions of the expedition. 1) Boat navigation from New Zealand through the South Ocean and into the Pack Ice. 2) Trapped in the Pack Ice. 3) The phenomenal 800 mile journey in the James Caird I have not investigated (1), although Shackleton gives precise Lat Long coordinates. I would be very surprised if Worsley used an alternate method here. That is, I think he used noon latitude and AM/PM longitude. When trapped in the pack ice, Shackleton indicates that the team used a theodolite and his sextant (probably with an artificial horizon) to "equal effect", down to a temperature which he specifies but escapes my memory. We have alread briefly discussed lunar occulatations, performed with a telescope. There is no doubt that the expedition is very mathematically adept. What form this is will have to wait until I get more log book data. When on the journey, Worsley used a Heath Hezzanith Sextant. This sextant tours with the Caird. The sextant has multiple features. It has multiple scopes and an attachable binocular (!). Many of the scopes have the lines as indicated by Bowditch to be used to adjust the parallelism of the scope to the arc. Further, there is a star scope and many eye piece filters. Quite the advanced sextant, with so many options. Best Regards Brad --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---