Horrocks , Jeremiah
(1619–1641) English astronomer
Little is known about the early life of Horrocks (or Horrox) other than that he was born into a Puritan family in Toxteth, Liverpool, and was admitted to Cambridge in 1632. Even though he died ‘in his twenty second year’ he had made major contributions to astronomy and several original observations.
Horrocks noted that as the orbits of Venus and Mercury fall between the earth and the Sun, it would seem possible that at certain times the inner planets would appear to an observer on the Earth to cross the face of the Sun. The events, known as transits, are so rare that they are unlikely to be seen by chance. Only five transits of Venus have been observed, those of 1639, 1761, 1769, 1874, and 1882; the next is due in 2004.
At Cambridge, Horrocks had mastered the new astronomy of Kepler. From Kepler's recently published Rudolphine Tables(1627), he worked out that a transit of Venus was due on 24 November 1639 at 3 p.m. At this time he was probably working as a curate at Hoole near Preston in Lancashire. He prepared for the transit by directing the solar image on to a large sheet of paper in a darkened room. However, a late November afternoon in Lancashire is not the best time to observe the Sun. For Horrocks there was another problem. The predicted day was a Sunday which meant that the puritan curate could well find himself in church at the crucial moment.
Horrocks was successful in observng the transit, however, and left an account of the day in his Venus in Sole Visa (Venus in the Face of the Sun), published posthumously in 1662. The day was cloudy but at 3.15, “as if by divine interposition” the clouds dispersed. He noted a spot of unusual magnitude on the solar disc and began to trace its path; but, he added, “she was not visible to me longer than half an hour, on account of the Sun quickly setting.”
With the aid of his observations Horrocks could establish the apparent diameter of Venus as 1' 12'' compared with the Sun's diameter of 30', a figure much smaller than the 11' assigned by Kepler. Horrocks also attempted to determine the solar parallax, and derived, although with little confidence, a figure of 15'', compared with a modern value of 8''.8.
Before his death Horrocks was working on an Astronomia Kepleriana (Astronomy of Kepler), and essays on comets, tides, and the Moon. Unfortunately none of this was published until long after his death. Much of his work had been lost in the chaos of the Civil War. Other material sent to a London bookseller was burnt in the Great Fire of 1666. The remainder of his papers were published by John Wallis as Opera posthuma (1678; Posthumous Works).

Scientists. . 2011.

Look at other dictionaries:

  • Horrocks, Jeremiah — ▪ British astronomer Horrocks also spelled  Horrox   born c. 1617, , Toxteth Park, near Liverpool [now in Merseyside], Eng. died Jan. 3, 1641, Toxteth Park       British astronomer and clergyman who applied Johannes Kepler s laws of planetary… …   Universalium

  • HORROCKS, JEREMIAH —    a celebrated astronomer, born at Toxteth, near Liverpool; passed through Cambridge, took orders, and received the curacy of Hoole, Lancashire; was devoted to astronomy, and was the first to observe the transit of Venus, of which he gave an… …   The Nuttall Encyclopaedia

  • Jeremiah Horrocks — Jeremia Horrocks, bei der Vermessung des Venustransits. J. W. Lavender, 1903. Jeremiah Horrocks (* 1619 in Toxteth Park, bei Liverpool in Lancashire; † 3. Januar 1641), manchmal auch Jeremiah Horrox geschrieben, war ein englischer Astronom.… …   Deutsch Wikipedia

  • Jeremiah Horrox — Jeremia Horrocks, bei der Vermessung des Venustransits. J. W. Lavender, 1903. Jeremiah Horrocks (* 1619 in Toxteth Park, bei Liverpool in Lancashire; † 3. Januar 1641), manchmal auch Jeremiah Horrox geschrieben, war ein englischer Astronom.… …   Deutsch Wikipedia

  • Jeremiah Horrocks — Observation du transit de Vénus en 1639 Naissance 1619 (?) Lower Lodge, Otterspool, Toxteth Park, près de Liverpool (Angleterre) Décès 3 janvier …   Wikipédia en Français

  • Jeremiah Horrox — Jeremiah Horrocks Observation du transit de Vénus par Jeremiah Horrocks en 1639. Jeremiah Horrocks est un astronome anglais du XVIIe (1619 (?) 3 janvier 1641) …   Wikipédia en Français

  • Jeremiah Horrocks — haciendo la primera observación del Tránsito de Venus en 1639. Jeremiah Horrocks (1618 3 de enero de 1641) también llamado Jeremiah Horrox fue un astrónomo inglés que fue el primero en hacer la observación del tránsito de Venus. Horrocks nació en …   Wikipedia Español

  • Horrocks — may refer to the following people: * Jeremiah Horrocks (c. 1618–1641), English astronomer * John Horrocks (1768–1804), British cotton manufacturer * John Horrocks (1816 1881), British born resident in Weimar, army officer, author, inventor,… …   Wikipedia

  • Horrocks —   [ hɔrəks], Họrrox, Horrocius, Jeremiah, englischer Astronom, * in der County Lancashire um 1619, ✝ Toxteth Park (heute zu Liverpool) 13. 1. 1641. Horrocks beobachtete 1639 einen von ihm selbst vorherberechneten Venusdurchgang (»Venus in Sole… …   Universal-Lexikon

  • Jeremiah Horrocks — Infobox Scientist name = Jeremiah Horrocks box width = image width = 240px caption = making the first observation of the transit of Venus in 1639 birth date = 1618 birth place = Lower Lodge, Otterspool, Toxteth Park, nr Liverpool, Lancashire,… …   Wikipedia

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