Records of the Harvard College Observatory Director Edward Charles Pickering

Scope and Contents Letterbook E2, Letterbook E3, and Letterbook E4 document the second Peruvian expedition to Arequipa, Peru, from 1891 to 1892 to establish a southern observatory station. Pickering’s letterbooks contain articles detailing the results of his Arequipa research activities. In August 1891, Pickering recaps the establishment and work completed at Arequipa, in The Boyden Station of the Harvard College Observatory (page 175). Pickering describes the atmospheric...

Scope and Contents

Many of Pickering's articles highlight the speculative nature of his visual studies of the planets. In reports written in August 1892, Pickering addresses changes to the surface of Mars, identifies canals, and notes his observations of green areas near Mars’s poles (pages 165, 302). In Can a Planet absorb its Oceans without having its Surface Temperature lowered? (August 1892), Pickering surmises that Mars once had extensive oceans (page 175).

Scope and Contents

Letterbook E4 continues to document the second Peruvian expedition to Arequipa, Peru, from 1892 to 1893; a trip to Flagstaff, Arizona, from 1893 to 1894; and the first and second Jamaican expeditions from 1899 to 1901.Found in this letterbook is Douglass’s description of the fossils he and William discovered at Lake Titicaca, a large deep lake in the Andes on the border of Bolivia and Peru during a minor expedition to establish a meteorological station in 1892 (page 82).