"On the Inclination of the Apparent to the True Horizon and the Errors Rising Thereof in Transit, Altitude, and Azimuth-Observations" read before the American Philosophical Society, February,, 1882

"On the Inclination of the Apparent to the True Horizon and the Errors Rising Thereof in Transit, Altitude, and Azimuth-Observations" read before the American Philosophical Society, February,, 1882, box-folder: 39. Georgetown Observatory Collection, GRB-000010. Georgetown University Rare Books , Booth Family Center for Special Collections. https://findingaids.library.georgetown.edu/repositories/14/archival_objects/1163457 Accessed June 15, 2024.