James Glaisher FRS (7 April 1809 – 7 February 1903) was an English meteorologist and aeronaut.Born in Rotherhithe, the son of a London watchmaker, Glaisher was a Junior assistant at the Cambridge Observatory from 1833 to 1835 before moving to the Royal Greenwich Observatories, where he served as Superintendent of the Department of Meteorology and Magnetism at Greenwich for thirty-four years.In 1845, Glaisher published his dew point tables, for the measurement of humidity. He was elected a Fellow of the Royal Society in June 1849.He was a founder member of the Meteorological Society (1850) and the Aeronautical Society of Great Britain (1866). He was president of the Royal Meteorological Society from 1867 to 1868.He is most famous, however, as a pioneering balloonist. Between 1862 and 1866, usually with Henry Tracey Coxwell as his co-pilot, Glaisher made numerous ascents in order to measure the temperature and humidity of the atmosphere at its highest levels. His ascent on 5 September 1862 broke the world record for altitude, but he passed out around 8,800 metres before a reading could be taken. One of the pigeons making the trip with him died. Estimates suggest that he rose to more than 9,500 metres and as much as 10,900 metres above sea-level.Glaisher lived at 22 Dartmouth Hill, Blackheath, London, where there is a blue plaque in his memory. He died in Croydon, Surrey in 1903.He had married in 1843 Cecilia Louisa, a daughter of Henry Belville, Assistant at the Royal Observatory, Greenwich. James and Cecilia Glaisher had three children, including the mathematician James Whitbread Lee Glaisher (1848–1928).