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Sextant

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probably made in London

Sextant
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The design for this type of sextant was patented in 1788 by Edward Troughton, a scientific instrument maker based in London. This brass example was made around 1820, probably by Troughton.

The 10-inch 'pillar frame' sextant has two thin frames of plate brass held together by a series of brass pillars. It has a platinum scale (which would not tarnish), an early example of the recently discovered metal being used in instrument design.

The English chemist, William Hyde Wollaston (1766-1828) managed to isolate platinum chemically in 1804. Troughton, who had introduced a new method of engraving sextant scales in 1785, realised that the hardness of this metal made it ideal for scale engraving.

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