George Willis Ritchey

George Willis Ritchey 1864-1945, American astronomer, b. Meigs co., Ohio, studied at the Univ. of Cincinnati (1883-84, 1886-87). He was superintendent of instrument construction (1899-1904) at Yerkes Observatory and then (1905-9) was associated with the Solar Observatory of Carnegie Institution. From 1901 to 1905 he taught astronomy at the Univ. of Chicago. Ritchey was in charge of the designing and construction of the 60-in. (152-cm) and 100-in. (254-cm) reflecting telescopes at Mt. Wilson Observatory. Later he went to the Paris Observatory as director (1924-30) of the astrophotographic laboratory. He is coinventor of the Ritchey-Chrétien reflecting telescope, and he supervised (1931) the construction of a 40-in. (102-cm) telescope of that type for the U.S. Naval Observatory. The cellular type of optical mirror was also his invention.

Ritchey, GeorgeWillis (1864–1945)Americanastronomer and optician. At Mount Wilson Observatory he made the mirror for the 60-inch (1.5-m) telescope and supervised the work on the mirror for the 100-inch (2.5-m). With these instruments he discovered dark lanes in the Andromeda Galaxy, and in 1917 he took the first photographs of novae and supernovae in the Andromeda Galaxy, providing the first means of estimating its distance. He also took the first photographs to show globular clusters around other galaxies. He later collaborated on the design of the Ritchey–Chrétien telescope, the first of which was completed in 1930.