NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Instrument for HA, Lat ... of points on the Sumner line may be directly obs at sea
From: Dave Walden
Date: 2009 Oct 6, 05:14 -0700
From: Dave Walden
Date: 2009 Oct 6, 05:14 -0700
Appears to be a device which combines the mechanical solution using arcs, of the navigation triangle with a bubble sextant and a number of prisms. My quick read says you set the dec, the assumed lat, center the object in the bubble, and read out the LHA. OR set dec, LHA, center obj and read out lat. Two settings and sights (assumed/read out dec and LHA changing, the Alt may be the same ((or close))), and you have you Sumner line! http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1927PASP...39.305K&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf and the patent (US Pat 1,852,166): http://www.google.com/patents/download/A_COPARTNERSHIP_CONSISTING_OF.pdf?id=gYFZAAAAEBAJ&output=pdf&sig=ACfU3U3ICy-mooq_x6rZq2CH-C2rAiDK4A H-C2rAiDK4A --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---