Measurement of the Diameter of alpha (a) Orionis with the Interferometer
Washington DC: Carnegie Institution, 1921. First printing. Wraps. Offprint from the Astrophysical Journal, LIII, 1921. 8vo, publisher's gray-blue wraps, very good, 11 pp, illustrated, one plate. Michelson won the Nobel Prize in 1907 for his studies in the speed of light. Contributions from the Mount Wilson Observatory no. 203.