Percival Lowell
Dr. Colton made an immediate connection in Flagstaff scientific circles during the first summer they camped in Flagstaff, due to a letter of introduction from Professor Edward S. Morse, a personal friend of both Dr. Colton and Percival Lowell, to Dr. V.M. Slipher of Lowell Observatory. The Observatory, founded in Flagstaff in 1894 by Percival Lowell and the site of pioneering astronomical work, is located in Flagstaff specifically for the clear dark skies that present opportunities for unclouded space study.