11 ¾ Inch Pillar-frame Sextant of Troughton, No. 119 on its own tripod, 1795
Item 7.12 : Artificial horizon by Troughton & Simms, 1850
Troughton, London
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A large sextant type Pillar frame, on its own heavy tripod. Used for surveying. Because there is no good horizon on land, an artificial horizon was used at the same time, e.g. a mercury-filled bath, which functioned as a perfect horizontal mirror. one could measure the double angle between the celestial body and its reflection, and then divide by two.
Anodised brass straight-bar-pattern pillar frame ( 24 pillars), wooden handle. Including ea big tripod Stand in Brass with two counterweights. Five telescope and one magnifying glass. All fitted together in a mahogany keystone box with some small damages.
Four shades for index glass. Three shades for the horizon are missing or not necessary on land.
In the lid there is a trade label of John Bruce, Instrumentmaker in Liverpool.
The Troughton brothers were active in London around about 1800. Edward Troughton (b.1765) carried on the business of instrument making after the death of his equally famous older brother, John, in 1788. By 1824, getting on in years, he took into partnership William Simms (b. 1793), describing him to an acquaintance as “the best craftsman he knew.” Troughton died in 1835 and Simms in 1860, but the business carried on as Troughton and Simms until 1916, when it became a Limited Company. It merged with T Cooke and Sons of York in 1922, to become the famous firm of instrument makers, Cooke, Troughton and Simms, with manufacturing being carried out in York, and offices and service centres in London and throughout the then British Empire. From the book: The Nautical sextant van W.J. Morris