Leslie Comrie
The astronomer who realised accounting machines could do astronomy, and got sacked for running them after hours.
Leslie John Comrie (1893–1950) was born in New Zealand and ended up an astronomer at His Majesty's Nautical Almanac Office, becoming its superintendent in 1930. Until then the almanac had been computed by hand, by outworkers paid per table row. Comrie looked at the Hollerith and Powers punched-card installations that businesses used for payroll and stock control, and saw that a tabulator able to add columns could just as happily sum a trigonometric series.
In 1928 he put Brown's lunar theory through a Hollerith installation: roughly half a million cards, twenty harmonic terms, a calculation that would have taken a decade with pencils. It is generally counted as the first use of commercial punched-card equipment for scientific computation. The Admiralty was less taken with his habit of accepting outside contracts on government machinery, and dismissed him in 1936. Comrie promptly founded Scientific Computing Service Ltd — the world's first commercial computing bureau — and sold the same service straight back.