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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Whole Horizon Mirror vs. Split Horizon Mirror
From: Henry Halboth
Date: 2015 Nov 30, 23:52 -0500
From: Henry Halboth
Date: 2015 Nov 30, 23:52 -0500
Hi All,
In 1946, or therabouts, I purchased the first Whole Hoizon Morror Sextant I had ever seen. I assume it was a Tamaya, made for the Japanese Navy during WWII - I say assumed because everything on the certificate was in Japanese. It was equipped with with a 7 x 50 monocular, micrometer drum reading in whole minutes only, and the legs were fitted to the front side of the instrument to facilitate one handed setting down. Probably due to the 7X magnification, no appreciable difference was noted between sights taken under all conditions, however, I considered the primary advantage of the WHM to be freedom from spray contamination and subsequent salt encrustation of the split mirror type, necessitating frequent cleaning. Regardless, controlling the instrument in high winds and/or rough seas became a problem and I soon changed to using a more conventional sextant. The front mounted legs however were a great advantage Photo attached.
Henry
On Mon, Nov 30, 2015 at 2:45 PM, Francis Upchurch <NoReply_Upchurch@fer3.com> wrote:
Thanks Mark,
I've asked Santa for a split mirror. Ive been happy with the WHM, but will try the split for stars and poor light conditions. I too learnt on the Davis Plastics 20 years ago, but have been very happy with the Astra B with WHM for the last 10-15 or so, including lunars for the last 5.
Best wishes
Francis
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