NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Henry Halboth
Date: 2010 Jan 8, 19:26 -0800
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Hi Frank, I believe it safe to say that by the mid-1940s transition from vernier to micrometer drum sextants was well underway, if not actually completed. It as just that the micrometer drum sextants were not generally commercially available in the USA – certainly the military, both Allied and Axis, had them and they were being issued to new built merchant ships by the Maritime Administration, but over the counter sales were non-existent or, at least, very limited, thereby extending the life and availability of older vernier sextants which could still be found on the 2nd hand market The opposite situation prevailed in Great Britain where you could walk in and by a Husun “three ring” micrometer sextant over the counter most anytime after 1943, or thereabouts – IMHO this latter simple sextant contributed materially to the winning of the Battle of The Atlantic, and most Allied Seamen that I knew aspired to owning one. Micrometer sextants apparently were around, although not plentiful, since at least the 1920s, facilitated by the incorporation of the rack and pinion drive arrangement for movement of the index arm – I personally have never seen such an instrument without this drive arrangement, which was also incorporated into the vernier type sextant by Plath in later years, thus doing away entirely with the old style index arm clamp and friction fine adjustment arrangement in which the tangent screw could come “two blocks”. My first “sextant” was actually a John Bliss & Co. octant, purchased second hand (more likely third to fifth hand) at their establishment on Pearl Street in New York City in late 1943 – it was then probably in the order of 60 to 80 years old, had the old style index arm clamp and limited run friction fine adjustment device for a 15 second vernier, and was encrusted with a dark green coating of verdigris, making it a real “salty old dog”. Well sir, this old dog navigated me over a good part of the world and competed favorably in every day sights, including stars, with any modern sextant it came up against; it stared my lifelong affinity fort vernier sextants – I still have it today. Subsequently, I did join the crowd. While lying on the hook in the convoy anchorage off Gourock, Scotland, I got enough time off to catch the AM train to Glasgow, where the Winfred O. White establishment was located directly across from the Station, purchase a Husun “three ring” sextant for about $60.00, and return to my ship by way of the PM train. I have since owned and used German, Japanese, and British micrometer sextants of every description, but finally settled on a relatively simple Plath, certificated in 1946, fitted with a 10 second double spaced vernier, and endless tangent screw, i.e., rack and pinion drive. My preference for the Plath resides primarily in the telescope, which I simply find to be personally more comfortable in use. Sorry to offend those who don’t like sea stories, but you did ask. Regards, Henry
--- On Fri, 1/8/10, FrankReed@HistoricalAtlas.com <FrankReed@HistoricalAtlas.com> wrote:
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