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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant Terms
From: Nicol�s de Hilster
Date: 2007 Oct 22, 08:46 +0200
From: Nicol�s de Hilster
Date: 2007 Oct 22, 08:46 +0200
Dan Allen wrote: > IF a sextant: > > 1) has a frame with an arc of 60 degrees, > > 2) can measure 120 degrees due to the double reflecting principle, > > THEN > > 3) how can it measure 140 degrees? > > > There are surveyors sextants (C. Plath for instant) that have an additional pentagon prism attached. This prism adds 90 degrees to the observed angle, so measuring 140 degrees should be no problem with that prism attached. One has been for sale on E-bay recently: http://cgi.ebay.co.uk/US-Coast-Guard-Weems-Plath-Sextant-w-Case_W0QQitemZ300160900331QQihZ020QQcategoryZ37971QQssPageNameZWDVWQQrdZ1QQcmdZViewItem Nicol�s --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
