NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2020 Dec 14, 09:12 -0800
At yesterdays “Office Hours” meeting there was discussion of the use of polarised light to detect the direction of the Sun in twilight. I mentioned that the RAF had a periscopic sextant mod designed to make use of this to get a heading check. The Smiths Mk2T sextant was an ordinary Smiths Mk2 periscopic sextant with a polaroid analyser attached to the eyepiece. The photographs below show the pages from the relevant Air Publication. The description says that it was imperative that the initial factory setting of the attachment’s position was not interfered with. That being the case, it’s doubtful if the MK2T would have been ideal for normal observations. You would have had to take two sextants with you, an ordinary Mk2 for use when either the Sun or stars were visible and a Mk2T for Polar twilight conditions when there were neither Sun nor many stars to observe. DaveP
