Leslie Comrie

Leslie Comrie
Born	(1893-08-15)15 August 1893 Pukekohe, New Zealand
Died
Nationality	New Zealand
Fields	Astronomy
Alma mater	Auckland University College
Known for	Ephemeris calculation automation
Influences	Ernest William Brown
Influenced	Wallace J. Eckert
Notable awards	Fellow of the Royal Society

Leslie John Comrie FRS (15 August 1893 – 11 December 1950) was an astronomer and a pioneer in mechanical computation.

Life

Leslie John Comrie was born in Pukekohe (south of Auckland), New Zealand, on 15 August 1893. He attended Auckland University College (part of the University of New Zealand) from 1912 to 1916, graduating with BA and MA degrees with Honours in Chemistry. During World War I, despite severe deafness, he saw action in France with the New Zealand Expeditionary Force, and lost his left leg in February 1918 to a British shell. While convalescing he started using a mechanical calculator and went on to modify commercial calculators for specific projects.

Having joined while in school in New Zealand, Comrie was eventually the first director (1920–1922) of the Computing Section of the British Astronomical Association. In 1923 he received a PhD from St John's College of the University of Cambridge. He traveled to the USA to teach at Swarthmore College and then Northwestern University in 1924 where he pioneered the teaching of numerical analysis. He returned to England to join HM Nautical Almanac Office at the Royal Greenwich Observatory where he became deputy superintendent in 1926.

In April 1928 his article On the Construction of Tables by Interpolation described the use of punched card equipment for interpolating tables of data, comparing this with the less efficient and more error-prone methods using mechanical devices such as the pinwheel calculators under the Brunsviga brand name. Also in 1928, he was the first to use punched card equipment for scientific calculations, using Fourier synthesis to compute the principal terms in the motion of the Moon for 1935 to 2000 improving the predictions of Ernest William Brown. Wallace J. Eckert, an American student of Brown at Columbia University would in turn use the vast resources of IBM corporation to improve on the predictions even further.

He was promoted to Superintendent of the Nautical Almanac Office in 1930. However, his unconventional use of machines for calculation caused tensions with his superiors, and he was suspended in August 1936.

Comrie founded the world's first private company for scientific computing, incorporated as Scientific Computing Service, Limited in 1937. During World War II he headed a team of 30 scientists to computerise war work, such as the creation of bombing tables for the Allies of World War II. Later he computerised British football pools.

After the war Comrie visited the USA and New Zealand in 1948. Comrie was elected a Fellow of the Royal Society of London in March 1950.

He is also remembered for his work in astronomy, publishing both scientific and poplar articles on subjects from predicting eclipses to the green flash. He died aged 57 on 11 December 1950 after a series of strokes. A lunar crater (23.3N 112.7W) and an asteroid, 3521 Comrie, bear his name, as does the computer lab at his alma mater, the University of Auckland, named on the 50th anniversary of his death.

External links

• (includes photographs, references, bibliography, and publication list)
• Recording of an interview with Comrie titled Mathematics in war on radio station 1YA on 5 April 1948 (MP3 format)
• Extract from Peter Isaac's Computing in New Zealand p64 at the Wayback Machine (archived March 10, 2005)