In 1930, Harlow Shapley and his colleagues at the Harvard College Observatory started a survey of galaxies in the southern sky, using photographic plates obtained at the 24-inch Bruce telescope at Bloemfontein, South Africa. By 1932, Shapley reported the discovery of 76,000 galaxies brighter than 18th apparent magnitude in a third of the southern sky, based on galaxy counts from his plates. Some of this data was later published as part of the Harvard galaxy counts, intended to map galactic obscuration and to find the space density of galaxies.