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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Sextant Telescope
From: Andy Howse
Date: 2024 Jul 17, 23:40 -0700
From: Andy Howse
Date: 2024 Jul 17, 23:40 -0700
Theodolite telescopes have "Cross Hairs" which, ensure that a target is in the centre of the instrument. But with theodilites you are measuring to seconds of arc where as a sextant is graduated in minutes of arc. I can think of two reasons why cross hairs may be included in a sextant telescope.
1. An implied improvement in precision can warrant a higher cost.
2. The telescope lenses are manufactured by a company that manufactures lenses for theodolites and cross hairs are included because that is what always do.
Andy H
