Scope and Contents: This series contains astronomical observations and data calculations spanning the early history of the Harvard College Observatory from 1848 until 1877, though most materials date to the subsequent directorships of H.C.O. founder William Cranch Bond and then his son George Phillips Bond prior to his death 1866. Astronomers whose work is represented in this series include: William Cranch Bond, George Phillips Bond, Richard F. Bond, Benjamin Pierce, Charles W. Tuttle, Horace P....

Scope and Contents: This series contains astronomical observations, data calculations, and administrative notes from the beginning of Edward Pickering’s tenure as Director of the Harvard College Observatory with the bulk of the materials dating from 1870 to 1905. The notebooks in this series feature early efforts in variable star analysis and meridian circle work, including HCO efforts to contribute zone measurements to contemporary revisions of the Bonn Durchmusterung. Additional records in this series...