seamus dubhghaill

Promoting Irish Culture and History from Little Rock, Arkansas, USA


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Birth of Astronomer William Edward Wilson

William Edward Wilson, Irish astronomer, is born at Greenisland, County Antrim, on July 19, 1851. He is the only son of John and Frances Wilson of Daramona House, Streete, County Westmeath, and is privately educated.

Wilson becomes interested in astronomy and travels to Oran in 1870 to photograph the solar eclipse. In 1871 he acquires a reflecting telescope of 12 inches (30.5 cm) aperture and sets it up in a dome in the gardens of Daramona House. He uses it to experiment on the photography of the moon with wet plates and also begins to study solar radiation using thermopiles. In 1881, he replaces the original telescope with a Grubb reflector of 24 inches (61 cm) aperture and a new dome and mounting that has an electrically controlled clock drive. The new telescope is mounted in a two-story tower attached to the house with an attached physical laboratory, darkroom and machine shop.

Wilson’s main research effort, in partnership with P.L. Gray, is to determine the temperature of the sun using a “differential radio-micrometer” of the sort developed by C.V. Boys in 1889, which combines a bolometer and galvanometer into one instrument. The result of their measurements is an effective temperature of about 8000 °C for the sun which, after correction to deal with absorption in the earth’s atmosphere, give a value of 6590 °C, compared to the modern value of 6075 °C.

Some of Wilson’s other astronomical projects include observations on the transit of Venus, determination of stellar motion, observations of sunspots and a trip to Spain to photograph a solar eclipse. He takes a great many excellent photographs of celestial bodies such as nebulae. His astronomical findings are published in a series of memoirs such as Experimental Observations on the Effective Temperature of the Sun.

Wilson is elected a fellow of the Royal Astronomical Society in 1875 and a Fellow of the Royal Society in 1896. He receives an honorary doctorate (D.Sc.) from the University of Dublin in June 1901. He serves as High Sheriff of Westmeath for 1894.

Wilson dies on March 6, 1908 at Daramona at the relatively young age of 56, and is buried in the family plot in Steete churchyard. He had married Caroline Ada in 1886, the daughter of Capt. R.C. Granville, and they have a son and two daughters. His son donates his telescope to the University of London, where it is used for research and teaching, finally becoming a feature in Liverpool museum.


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Birth of William Frederick Archdall Ellison, Clergyman & Astronomer

Reverend William Frederick Archdall Ellison FRAS, Irish clergyman, Hebrew scholar, organist, avid amateur telescope maker, and, from 1918 to 1936, director of Armagh Observatory in Armagh, Northern Ireland, is born on April 28, 1864. He is the father of Mervyn A. Ellison, the senior professor of the School of Cosmic Physics at Dunsink Observatory from 1958 to 1963.

Ellison comes from a clerical family, his father Humphrey Eakins Ellison having been Dean of Ferns, County Wexford. He gains a sizarship of classics at Trinity College, Dublin in 1883, becomes a Scholar of the House in 1886 and graduates in 1887 with junior moderatorships in classics and experimental science. In 1890 he takes Holy Orders and moves to England, where he becomes the Curate of Tudhoe and Monkwearmouth. In 1894 he takes his MA and BD degrees and in the following year wins the Elrington Theological Prize.

In 1899 he returns to Ireland to become secretary of the Sunday School Society, a post which he holds for three years before accepting the incumbency of Monart, Enniscorthy, moving in 1908 to become Rector of Fethard-on-Sea with Tintern in Wexford. Ellison develops an interest in astronomy, having been introduced to practical optics by Dr. N. Alcock of Dublin and sets up his first observatory at Wexford. He becomes highly adept at making lenses and mirrors and writes several books and articles on the subject, including major contributions to the Amateur Telescope Making series, the Journal of the British Astronomical Association, and the weekly newspaper The English Mechanic. His book The Amateur’s Telescope (1920) is still considered a standard for telescope-makers and a forerunner of the more extensive series on the same topic by Albert Graham Ingalls.

On September 2, 1918 Ellison is appointed Director of the Armagh Observatory. He finds the Observatory in a state of disrepair and sets about repairing the instruments and the observatory dome. On January 3, 1919 he deeds a telescope of his own to the observatory, an 18-inch reflecting telescope, which is still there.

Ellison is a highly regarded planetary and binary star observer. Working with his son Mervyn, he makes many measurements of binary stars using the observatory’s 10-inch Grubb refracting telescope and even discovers a new one close to Beta Lyrae, and according to Patrick Moore, is one of the few people to have observed an eclipse of Saturn’s moon Iapetus by Saturn’s outermost ring on February 28, 1919.

In 1934 Ellison becomes Canon and Prebendary of Ballymore, Armagh Cathedral. He dies on December 31, 1936, having held the office of Director of the observatory for nearly twenty years.