Human computer

The term "computer", in use from the early 17th century (the first known written reference dates from 1613), meant "one who computes": a person performing mathematical calculations, before electronic computers became commercially available. "The human computer is supposed to be following fixed rules; he has no authority to deviate from them in any detail." (Turing, 1950) Teams of people were frequently used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel.

Since the end of the 20th century, the term "human computer" has also been applied to individuals with prodigious powers of mental arithmetic, also known as mental calculators.

The approach was taken for astronomical and other complex calculations. Perhaps the first example of organized human computing was by the Frenchman Alexis Claude Clairaut (1713–1765), when he divided the computation to determine timing of the return of Halley's Comet with two colleagues, Joseph Lalande and Nicole-Reine Lepaute.

For some men, being a computer was a temporary position until they moved on to greater advancements. For women the occupation was generally closed, with some exceptions such as Mary Edwards who worked from the 1780s to 1815 as one of thirty five computers for the British Nautical Almanac used for navigation at sea. This changed in the late nineteenth century with Edward Charles Pickering. His group was at times termed "Harvard Computers". Many of the women astronomers from this era were computers with possibly the best known being Henrietta Swan Leavitt, who worked with Pickering from 1893.

Florence Cushman was another of the Harvard University computers from 1888 onward. Among her best known works was A Catalogue of 16,300 Stars Observed with the 12-inch Meridian Photometer. She also worked with Annie Jump Cannon.

...
Wikipedia