In his autobiography he tells how, at the age of five, he began to study arithmetic, at twelve algebra, and at thirteen Euclid. At the age of eighteen, planning to make his way to the United States, he set out on foot, taught school for a year or so, and then attracted the attention of Prof. Joseph Henry, of the Smithsonian Institution, by sending him a problem in algebra. The unusual aptitude for mathematics which the boy possessed so impressed Prof. Henry, that he set him to work as a computer on the Nautical Almanac; but he was soon attracted to "exact," or mathematical astronomy, which became his life work. Some idea of its importance may be gained when it is stated that every astronomer in the world to-day uses his determinations of the movements of the planets and the moon; every skipper in the world guides his ship by tables which Newcomb devised; and every eclipse is computed according to his tables. He supervised the construction and mounting of the equatorial telescope in the naval observatory at Washington, the Lick telescope, and Russia applied to him, in 1873, for aid in placing her great telescope. A man of humor, sympathy and anecdote, he found, in the fall of 1908, that he was suffering from cancer, and hastened the work on the moon, which was to be his masterpiece. Ten months later, he was told that his course was nearly run--and his great work was still incomplete. "Take me to Washington," he said, "I must work while there is time." And there, lying in agony on his bed, for three weeks he dictated steadily to stenographers on a subject which required the utmost concentration. His indomitable will alone supported him, and a week after the last word had been written, came the end. Verily, there was a man!