NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Chuck Varney
Date: 2024 Nov 22, 11:20 -0800
Frank, you wrote: “See the image below. Feel free to correct me if I'm wrong, but I believe that sextant on British television is an American sextant, a USN Mk.II, isn't it?”
I can confirm that you are correct. I have attached a crop of the image you posted. While there are variants of the USN MARK II that deviate in particulars from that in your post, I have attached a photo of one that is nearly identical to it, one manufactured by David White in the 1940’s. It appears to differ in the shape of the micrometer knob, but other features are the same: the number and position of screws on the index arm, the release levers, the handle screw location, the index and horizon mirror filters, and what can be seen of the frame pattern.
The same model sextant is shown in the third and fourth attachments to this post: pages 353 and 354 from the 1969 Dover edition of “Basic Optics and Optical Instruments”. (The text doesn’t give the model name or number—only that it’s a Navy sextant manufactured by David White.)
Chuck V.
