In the mid-19th century, the Harvard Observatory began employing women as computers, to do the calculations that were the necessary next step after observations were made and recorded. It was considered inappropriate to subject women to the rigors of nighttime observation work, but there was no reason they couldn't do the essential mathematics. Initially, these women were often family members of the director or other astronomers, introduced to the field by their husbands, brothers, or fathers. As time went on and the demand for good computers grew, though, it became a field of science unusually open to women who were increasingly able to pursue formal scientific education.
