https://en.wikipedia.org/wiki/Computer_(occupation)
which says that "(the first known written reference dates from 1613)... often women from the late nineteenth century onwards, were used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel."
Review of 2005 book "When Computers Were Human" 424pp. ISBN: 0-691-09157-9
https://web.archive.org/web/20060821120909/http://www.pupres...
https://en.wikipedia.org/wiki/Computer_(occupation)
which says that "(the first known written reference dates from 1613)... often women from the late nineteenth century onwards, were used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel."