COMRIE, Leslie John, F.R.S.
Astronomer and computer.
Leslie John Comrie was born at Pukekohe on 15 August 1893. He gained his M.A. at Auckland University in 1916 with honours in Chemistry. In spite of the handicap of deafness, he served with the New Zealand Expeditionary Force in the First World War and was wounded, with the loss of a leg. Forsaking chemistry, he followed an earlier interest in astronomy and computation, in which he was destined to become a master. Proceeding to St. John's College, Cambridge, as a research student, he was elected to an Isaac Newton Scholarship in 1920. He was awarded the Ph.D. degree in 1923 for a thesis on occultations of stars by planets. From Cambridge he proceeded to the United States, where he spent three years teaching astronomy and introducing computational science into the undergraduate course, first at Swarthmore College, and then at North-Western University, Evanston, Illinois.
Appointed to His Majesty's Nautical Almanac Office in 1925, Comrie ultimately became its superintendent in 1930. In 1936 he left this position and founded in 1937 a private firm, Scientific Computing Service Ltd., London, which provided for the first time a general service for professional needs of high-volume calculation. During the Second World War this firm produced services with an accuracy and speed of which Comrie was justly proud. Ballistic, bombing, and geodetic tables were all compiled in effective fashion.
In 1948 he made a complete tour of New Zealand, revisiting old friends and places. He died in London on 11 December 1950. He was a fellow both of the Royal Astronomical Society and of the Royal Society.
Deafness and the physical disabilities of a lost leg may have been the reason for his apparent lack of great interest in things other than his chosen work of computational astronomy. On the other hand, to deal with such a subject on the scale undertaken by Comrie would leave little time for anything else. His impact on computational and precision astronomy may perhaps be appreciated only by those engaged in such subjects over the last few decades, but its immensity would soon be discovered if students had to revert to the methods in use before his time. Virtually he made the discovery that the then existing calculating machines, which were designed for commercial practice, could be adapted to scientific work, and that specialised machines need not be designed. Further, he showed that such machines had the inherent power to perform hitherto difficult tasks with great ease and accuracy. Before his time, at His Majesty's Nautical Almanac Office, all astronomical calculations were performed by hand, using logarithms. The development of machine work wrought a change which is still having its effect today in all branches of astronomy. The 1931 Nautical Almanac is a classic, demonstrative of this new approach.
Besides purely astronomical work, of which eclipses and occultations held his greatest interest, he became a foremost authority on the production of mathematical tables, of which the most famous may be the two volumes of Chamber's Six-Figure Mathematical Tables. For Comrie, “accuracy” had a specific and clear meaning, which could most often be acquired by the planning of elegant methods of work.
by Ivan Leslie Thomsen, F.R.A.S.(LOND.), Director, Carter Observatory, Wellington.