J. Brit. Astron. Assoc., 106, 6, 1996, p.354

Kenneth Essex Edgeworth A biographical note

On 1972 October 10 the Association lost one of its senior members when Kenneth Edgeworth died in Dublin at the age of 92. He only wrote one paper for the Association, which was published in the July 1943 issue of the Journal very shortly after he was elected a member on 1943 March 31. At the time of his death the paper had been largely forgotten and its basic importance has only been recognised very recently.

A biographical paper by J. McFarland giving a full account of Edgeworth's life and contribution to astronomy has been accepted for publication in Vistas in Astronomy, so I shall confine myself to a very brief review. He was born on 1880 February 26 at Daramona House, Streete, County Westmeathe, Ireland. Though his parents moved on four years after his birth, the house played a significant role in astronomical development. Edgeworth's uncle William E. Wilson established an observatory here with Grubb 12-inch and 24-inch reflectors. Investigations included an observation of the 1882 transit of Venus, the absorption of heat in the solar atmosphere, the measurement of the temperature of the Sun and the determination of the thermal radiation of sunspots. The observatory was fundamental in the story of photoelectric photometry as it was here that, in April 1895 and January 1896, Professor Minchin's photoelectric cell was first used to measure starlight by Wilson and Professor Fitzgerald.

At the age of 14 Edgeworth won a scholarship to Marlborough and three years later attended the Royal Military Academy at Woolwich. He earned a commission in the Royal Engineers and later the Royal Signals, serving through the First World War where he won the DSO and MC and was three times mentioned in despatches. After the War he was promoted to the rank of Lieutenant-Colonel and retired in 1926. From his published papers we know that his membership of the Institution of Electrical Engineers dates at least from this time.

He then spent five years in the Sudan in the Department of Posts and Telegraphs before returning to Ireland in 1931 to Cherbury, the last home of his parents, where he lived out the remainder of his life. Here he studied international economics at the time of the Depression and published four books on the subject. His uncle had aroused his interest in astronomy and during the 1940s Edgeworth published a number of papers on star formation, the origin and development of the Solar System, red shifts, and red dwarfs. The earliest so far traced was published in 1939.

His one paper published in this Journal was titled 'The Evolution of Our Planetary System'. It is recognised as the first reference (at least so far discovered) in which the suggestion is made of a reservoir of comets existing beyond the planets. He reasoned that there should be a very large number of small bodies, or clusters of bodies, which occasionally enter the inner solar system and appear as comets. He further noted that at this distance collisions between particles were so infrequent that only small bodies (or clusters) could form. This was published some seven years before the Oort Cloud was proposed and eight years before Kuiper presented his paper at the 50th anniversary symposium of Yerkes Observatory.

Later research and theoretical studies have been (and are being) carried out to explain the formation and evolution process of comets but it must be recognised that (as far as can be determined at this time) the first suggestion was made in these pages in 1943. Kenneth Edgeworth's autobiography, entitled Jack of All Trades The Story of My Life was published by Alan Figgis, Dublin in 1965.

Andrew Hollis
Director, Asteroids and Remote Planets Section

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