distance traveled by light in one year, and as light moves about 185,000 miles per second, the stupendous magnitude of the unit of measure they employ may dawn upon us. In estimating the place which Doctor Simon Newcomb has made for himself among the men who deal with the stupendous phenomena of the heavens, we need the testimony of experts who are competent to judge; and Newcomb's contemporary, M. Leowy, director of the Paris observatory, says of him: "Henceforth science will profit by the fruits of his immense labor; he is gifted with a prodigious power of work, which is testified by the extraordinarily long list of his researches. The reception which has been accorded to them by all competent men, points to their author as one of the most illustrious representatives of celestial mechanics. His activity has embraced the most diverse branches of astronomy and has enriched the domain of science with beautiful and durable conquests."
In 1906, Professor Newcomb is at work in his private office on some of the most difficult problems of mathematical astronomy.