John Pond (c. 1767 - September 7, 1836) was an English astronomer.
Pond was born in London, where his father made a fortune in trade. He entered Trinity College, Cambridge, at the age of sixteen, but took no degree, his course being interrupted by severe pulmonary attacks which compelled a long residence abroad. In 1800 he settled at Westbury near Bristol, and began to determine star-places with a fine altitude and azimuth circle of 2 1/2 feet in diameter by Edward Troughton. His demonstration in 1806 of a change of form in the Greenwich mural quadrant led to the introduction of astronomical circles at the Royal Greenwich Observatory, and to his own appointment as its head. He was elected a fellow of the Royal Society on February 26, 1807; he married and went to live in London in the same year, and in 1811 succeeded Nevil Maskelyne as Astronomer Royal.
During an administration of nearly twenty-five years Pond effected a reform of practical astronomy in England comparable to that effected by Friedrich Bessel in Germany. In 1821 he began to employ the method of observation by reflection; and in 1825 he devised means of combining two mural circles in the determination of the place of a single object, the one serving for direct and the other for reflected vision. Under his auspices the instrumental equipment at Greenwich was completely changed, and the number of assistants increased from one to six. The superior accuracy of his determinations was attested by Seth Carlo Chandler's discussion of them in 1894, in the course of his researches into the variation of latitude. He persistently controverted (1810-1824) the reality of John Brinkley's imaginary star-parallaxes. Delicacy of health compelled his retirement in the autumn of 1835.
The Copley Medal was conferred upon him in 1823, and the Lalande prize in 1817 by the French Academy of Sciences, of which he was a corresponding member. He published eight folio volumes of Greenwich Observations, translated Pierre-Simon Laplace's Systeme du monde, and contributed thirty-one papers to scientific collections. His catalogue of 1,112 stars (1833) was of great value.
As Astronomer Royal, Pond was responsible for a substantial modernisation of the Observatory at Greenwich extending from improvements to equipment to new working practices. Perhaps his most noticeable addition was the 1833 installation of the time ball on the roof of the Observatory. This - arguably, the first public time signal in the UK - falls daily at 1pm and was intended to help passing mariners on the River Thames check their chronometers.
He died in Blackheath, and was buried beside Edmond Halley, and near fellow Astronomer Royal Nathaniel Bliss, in the churchyard of St Margaret's in nearby Lee, London.
The core of this article originally from the 1911 Encyclopaedia Britannica.References
