In this week's episode we look at the early work of the Harvard College Observatory under the direction of Edward Charles Pickering. We discuss his three big research initiatives: the visual photometric survey of stars, the All-Sky Survey and Catalogue and the Draper Memorial Catalogue that catalogued and classified the spectra of over 10,000 individual stars. Instrumental in this last effort was Williamina Fleming: Pickering's one time housekeeper turned lead calculator in the project.