A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Dustin Baenen
Date: 2017 Sep 15, 14:59 -0700
I notice the last two pictures posted show sextants being used from the interior of the ship shooting "sights" through glass windows. I would think that the glass would create some kind of extra refraction error or perhaps just an abboration leading to reduced accuracy. I have no evidence to support this hypothosis, just seemd like "common sense". I assume these navigators were demonstrating the use of the sextant (the second photo shows the gentleman taking a sight with the index arm right around zero) for the photographer. Can someone please confirm this thought or set me straght? Is it ok to sight through a glass window? On my Davis AH there is two panes of glass that the light passes through before hitting the sextant but because they are at complimentary angles I assumed this cancled out any error the glass might produce. Im sorry that this was slightly off topic to the thread but it made me wonder.