Patrick Kelly (metrologist)

Patrick Kelly (1756–1842) was a British metrologist, best known for his comparative studies of weights and measures collected in his works Universal Cambist (1811) and Oriental Metrology (1832). Kelly was Master of the Finsbury Square Academy, London. He was also instrumental in the establishment of the Imperial system of measurement through the Weights and Measures Act 1824 (5 Geo. 4. c. 74).

Life
He was for many years master of a successful private school, the Mercantile School, in Finsbury Square, London. He was appointed mathematical examiner at Trinity House, and in 1813 had the degree of LL.D. conferred on him by the University of Glasgow. Charles Hutton's 1815 list of England's most notable private observatories included Kelly's observatory at Finsbury Square.

Kelly knew Nevil Maskelyne, John Herschel, James Hutton, and other men of science. He was consulted by committees of the House of Commons as an authority on questions of coinage and currency. He died at Brighton, 5 April 1842. A portrait of him by Harry Ashby was engraved by Thomas Woolnoth.