Percival Lowell Milan Observatory. In 1894 Lowell chose Flagstaff, Arizona Territory, as the home of his new observatory. At an altitude of over , with few cloudy nights, and far from city lights, Flagstaff was an excellent site for astronomical observations. This marked the first time an observatory had been deliberately located in a remote, elevated place for optimal seeing. For the next fifteen years he studied Mars extensively, and made intricate drawings of the surface markings as he perceived them. Lowell published his views in three books: "Mars" (1895), "Mars and Its Canals" (1906), and "Mars As the Abode of Life"
Percival Lowell Planet X. Lowell started a search program in 1906 using a camera in aperture. The small field of view of the reflecting telescope rendered the instrument impractical for searching. From 1914 to 1916, a telescope on loan from Sproul Observatory was used to search for Planet X. Lowell did not discover Pluto but later Lowell Observatory (observatory code 690) would photograph Pluto in March and April 1915, without realizing at the time that it was not a star. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of