Scientific instruments are devices designed for measuring, observing, calculating or experimenting, and antique examples are collected for their precision engineering, fine materials and historical importance. The field includes navigational instruments such as sextants, octants and compasses; astronomical instruments such as telescopes, orreries and globes; microscopes; surveying instruments; drawing and calculating instruments; barometers and thermometers; and medical and electrical apparatus.
London was a leading centre of instrument making from the late seventeenth century, with makers such as George Adams, Jesse Ramsden, Dollond and Troughton & Simms supplying scientists, navigators and wealthy amateurs. Instruments were typically made from lacquered brass, mahogany, ivory and glass, often housed in fitted cases. The eighteenth-century passion for natural philosophy made fine instruments fashionable possessions in country house libraries, and the Victorian period brought wider education and mass production. When collecting, consider the maker's signature, completeness, originality of lacquer and fittings, condition of optics and any original case, as these greatly affect value.
