He spent his entire career at Lowell Observatory in Flagstaff, Arizona, where he was promoted to assistant director in 1915, acting director in 1916, and finally director from 1926 until his retirement in 1952.
Ia menghabiskan keseluruhan kariernya di Observatorium Lowell di Flagstaff, Arizona, di mana ia dipromosikan menjadi asisten direktur tahun 1915, pelaksana tugas direktur tahun 1916, dan akhirnya direktur dari tahun 1926 sampai pensiunnya tahun 1952.