In the 1880s and 1890s, despite that fact that women's colleges were beginning to turn out graduates trained in the sciences, it was still rare to find women in the scientific professions. Edward Pickering, director of the Harvard Observatory from 1877 to 1919, broke with tradition out of necessity. He needed "computers" — human number crunchers — to do thousands of complex astronomical computations. There were few qualified men willing to do the job for what he was prepared to pay (25 cents an hour) so Pickering turned to women. In doing so, he created unprecedented opportunities for a generation of female astronomers.
Pickering's goal was ambitious. The telescope Harvard owned in Peru yielded glass plate photographs of the sky. These images made it possible to judge the color and brightness of stars more accurately than ever before. Pickering wanted to use the photographs to measure precisely the brightness (a clue to distance) and color (a clue to composition) of every star in the sky. Frustrated by the lack of good data, he resolved to complete the catalogue by poring over the glass plates, counting and calculating, for as long as it took.
But in the days before government and corporate funding of scientific research, money for this kind of undertaking was scarce. Pickering came up with a unusual solution. "A great savings may be effectuated by employing unskilled and therefore inexpensive labor, of course under careful supervision," he reasoned. He found his first prospect right in his own home.