Jonathan Sisson | |
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Born | 1690 Lincolnshire, England |
Died | 1747 (aged 56–57) London, England |
Nationality | English |
Occupation | Instrument maker |
Known for | Invention of the modern theodolite |
Jonathan Sisson (1690 – 1747) was a prominent English instrument maker, the inventor of the modern theodolite with a sighting telescope for surveying, and a leading maker of astronomical instruments.
Jonathan Sisson was born in Lincolnshire around 1690. He was apprenticed to George Graham (1673–1751), then became independent in 1722. He remained an associate of Graham and of the instrument maker John Bird (1709–1776). All three were recommended by the Royal Society and received some funding from the state, which recognised the value of instruments both to the Royal Navy and to merchant ships.
After striking out on his own in 1722 and opening a business in the Strand in London, Sisson gained a reputation for making highly accurate arcs and circles, and for the altazimuth theodolites that he made to his own design. He became a well-known maker of optical and mathematical instruments. In 1729 Sisson was appointed mathematical instrument maker to Frederick, Prince of Wales. His apprentice John Dabney, junior, was an early instrument maker in the American colonies, who arrived in Boston in 1739. His son, Jeremiah Sisson (1720–1783), also made instruments, and became one of the leading instrument makers in London. Sisson also employed John Bird, his co-worker under Graham, who became another leading supplier of instruments to the Royal Observatory. His brother-in-law, Benjamin Ayres, apprenticed under Sisson and then set up shop in Amsterdam in 1743.
Jonathan Sisson died during the night on 13 June 1747. An old friend recording the fact in his diary described him as a man of extraordinary genius in making mathematical instruments.
Sisson made portable sundials with a compass in the base for use in aligning the instrument with the earths axis. He also constructed barometers. A model Newcomen steam engine was given to Sisson to repair, but he was unable to make it work. However, Sisson became renowned for his instruments for surveying, navigation, the measurement of lengths and astronomy.