A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2015 Dec 5, 12:39 -0800
Thanks for the reference. That looks like an interesting book. There are quite a few copies of "Basic Optics and Optical Instruments" for sale through abebooks.com for less than $10, shipping included. Also this limited preview at Google Books includes many sections which can be viewed online including a few pages of the sextant chapter (when you get to the linked page on Google Books, scroll down to the "Contents" section to see samples of each chapter).