[4] Immediately upon graduating from Harvard he was hired as an instructor of mathematics there, and a year later he moved to the Massachusetts Institute of Technology to be an assistant professor of physics.[9] Later, Pickering served as director of Harvard College Observatory (HCO) from 1877 to his death in 1919, where he made great leaps forward in the gathering of stellar spectra through the use of photography.[10] This immense amount of photographic research has provided scientists for decades with a seemingly endless library containing the history of every visible star's movements.[20][21][22][23] Fowler was initially-skeptical but was ultimately convinced that Bohr was correct, and by 1915 "spectroscopists had transferred [the Pickering series] definitively [from hydrogen] to helium.College educated women from around the country offered to work for the Harvard Observatory unpaid to gain experience or until proving their value to be paid.During this time, Pickering recruited over 80 women to work for him, including Annie Jump Cannon, Henrietta Swan Leavitt, Antonia Maury, and Florence Cushman.[29][30] It was very unusual for such an accomplished scientist to work with this many women, but it has been said that he "became so exasperated with his male assistant's inefficiency, that even his maid could do a better job of copying and computing".[29] These women, the Harvard Computers (also described as "Pickering's Harem" by the male scientific community at the time), made several important discoveries at HCO.[30] Leavitt's discovery of the period-luminosity relationship for Cepheids, published by Pickering, would prove the foundation for the modern understanding of cosmological distances.It is true that they were underpaid compared to their male counterparts and were not given credit nearly as often, but his willingness to include them in the world of astronomy paved the way for many great female scientists and leaders.
Pickering at the Fourth Conference International Union for Cooperation in Solar Research at
Mount Wilson Observatory
, 1910