Female computers - Bill Bryson

Bill Bryson's latest, A short history of nearly everything is a good read. Here's a passage that gives us insight into the paucity of top female scientists.

Hubble's luck was to come along soon after an ingenious woman named Henrietta Swan Leavitt had to [know how far away stars are to begin with]. Leavitt worked at the Harvard College Observatory as a computer, as they were known. Computers spent their lives studying photographic plates of stars and making computations - hence the name. It was little more than drudgery by another name, but it was as close as could get to real astronomy at Harvard....The system, however unfair, did have unexpected benefits: it meant that half the finest minds available were directed to work that would otherwise have attracted little reflective attention....

(...at the time Leavitt and Cannon [another female computer] were inferring fundamental properties of the cosmos from dim smudges on photographic plates, the Harvard astronomer William H. Pickering ... was developing his seminal theory that the dark patches on the Moon were caused by swarms of seasonally migrating insects.)