11 ¾ Inch Pilaar-kader Sextant Nr. 119 op eigen driepoot, 1795
Met artificiële horizon Troughton & Simms 1850 = item 7.12
Troughton, London
Maker:
Collectie:
NavigArte
Een grote sextant type Pilaar-frame, om een eigen zware driepoot. Gebruikt voor landmeetkunde. Omdat er geen goede horizon aanwezig is op land gebruikte men tegelijk een artificiële horizon, vb. een met kwik gevuld bad, dat als perfecte horizontale spiegel fungeerde. Met kon de dubbele hoek meten tussen het hemellichaam en diens spiegelbeeld, en dan delen door twee.
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