A MAN of moods," Dr. Lowell called himself, and this he was, as the writer can attest after being associated with him in his work almost daily for many years. He changed in an instant from writing sober science to narrating a telling story to a friend who happened in, taking the keenest interest in visiting with him as if he had nothing else to occupy his mind. The masterly ease with which he wrote of astronomy or attended to mundane affairs was extraordinary. At Flagstaff he would often leave his computations for a bit of exercise on the mesa to explore a cañon near by. In the midst of dining he might be impelled to rush to his dome for a study of the heavens; also he might be wakened from his slumbers at the necromantic hour before dawn that he could revel in its splendor and then exclaim: "I have been so overcome by her roseate blush of surprised confusion that I feel like an impertinent intruder who would better have waited until expected by the Sun." In such ways he showed his marvellous versatility in work and mood.