Orrery planetary model by Troughton, 1775-1799.
© Science Museum / Science & Society Picture Library
Detail. Miniature orrery made by the well known English instrument-maker Edward Troughton (1753-1835). It has armillary bands and an octagonal base, and shows three planets including the Earth and Moon. Orreries are clockwork or hand-driven models of the Copernican (Sun-centred) solar system, named after Charles Boyle, Forth Earl of Orrery (1676-1731) who commissioned and purchased an early example. Orreries proved popular with lecturers and gentlemen at home and, during the 19th and 20th centuries, as educational aids.