William Derham FRS (26 November 16575 April 1735)[Smolenaars, Marja. ' Derham, William (1657–1735)', Oxford Dictionary of National Biography, Oxford University Press, 2004. Accessed 26 May 2007.] was an English clergyman, natural theology, natural philosopher and scientist. He produced the earliest reasonably accurate measurement of the speed of sound.
Life
William Derham was the son of Thomas Derham. He was born at
Stoulton, in
Worcestershire, England. He was educated at
Blockley,
Gloucestershire, and at Trinity College, Oxford, from 1675 to 1679.
He was ordained on 29 May 1681. In 1682, he became
vicar of
Wargrave,
Berkshire, and from 1689 to 1735 he was Rector at
Upminster,
Essex. While at Upminster, in 1716 he became a Canon of Windsor and the vestry minutes show that thereafter he divided his time between those two places. The parish registers of Upminster record his burial at St. Laurence's in 1735. However, the precise site of his grave is unknown and, in accordance with his wishes, there is no memorial to him in the church.
Work
In 1696, he published his
Artificial Clockmaker, which went through several editions. The best known of his subsequent works are
Physico-Theology, published in 1713;
Astro-Theology, 1714; and
Christo-Theology, 1730. All three of these books are
teleology arguments for the being and attributes of
God, and were used by
William Paley nearly a century later.
However, these books also include quantities of original scientific observations. For example,
Physico-Theology contains his recognition of natural variation within species and that he knew that
Didelphis virginialis (the
Virginia opossum) was the only marsupial in
North America. It also includes one of the earliest theoretical descriptions of a marine chronometer, accompanied by a discussion of the use of vacuum seals to reduce inaccuracies in the operation of timepieces. He is the first person known to have used the word
chronometer.
Similarly, Astro-Theology includes several newly identified (this was the name used at the time for all extended astronomical objects: some of his nebulae are what we would now call ). His telescope (also used when measuring the velocity of sound) was at the top of the tower of St Laurence's Church, where the necessary doors are still in place.
On 3 February 1703, Derham was elected Fellow of the Royal Society. He was Boyle Lectures in 1711–1712. His last known work, entitled A Defence of the Church's Right in Leasehold Estates, appeared as early as 1731.
But besides the works published in his own name, Derham contributed a variety of papers to the Transactions of the Royal Society. He revised the Miscellanea Curiosa.
He edited Eleazar Albin's Natural History, and published some of the manuscripts of the scientist Robert Hooke.
Speed of sound
In 1709 Derham published a more accurate measure of the speed of sound, at 1,072
Paris inch per second.
Derham used a telescope from the tower of the church of St Laurence, Upminster, to observe the flash of a distant shotgun being fired, and then measured the time until he heard the gunshot with a half second pendulum. Measurements were made of gunshots from local landmarks including the Church of St Mary Magdalene, North Ockendon. The distance was known by
triangulation, and thus the speed that the sound had travelled could be calculated.
Works
See also
External links
