A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Murray Buckman
Date: 2020 Aug 26, 11:03 -0700
Bill Morris answered your earlier question. Do you have specific further questions?
General comments: Henry Hughes and Son was an important supplier of scientific and navigation instruments long before WW1 and long after. The example you have is a three-circle frame, but before WW1 they had a wide selection of models with different frames. If you measure the radius of your sextant's arc is it probably 6 inches or just over. They had many models with 8" and 7" radii too, with what they called the pillar frame, the triangle frame and the diamond frame.
Incidentally, Scott's final expedition to the Antarctic was supplied with Henry Hughes sextants - a few years before the example you have. I see the scope does not appear in your photos. Do you have one or more that screw into the small circular collar one the right?