SELLERS, Coleman, dynamical engineer, born in Philadelphia, Pennsylvania, 28 January, 1827. He was educated at common schools and studied for five years with Anthony Bohnar in West Chester, Pennsylvania In 1846 he became draughtsman in the Globe rolling-mill in Cincinnati, Ohio, and he remained there for three years, during part of the time as superintendent. Mr. Sellers then engaged in the manufacture of locomotives, and served for five years as foreman in the works of Niles and Co. In 1856 he moved to Philadelphia, where he became chief engineer of William Sellers and Co. (the senior partner of which firm was his second cousin), makers of machinists' tools, and general millwrights. Since 1888 he has devoted himself chiefly to consulting practice. Mr. Sellers has obtained more than thirty letters-patent for inventions of his own, one of the first of which, a coupling device for shafting (1857), is the essential factor in the modern system of interchangeable shafting parts. His invention in 1866 of feed-disks for lathes or other machine tools was the first practical solution of the problem of the infinite gradation of feeds. His other patents relate chiefly to improved forms of tools or modifications of existing machines. The use of absorbent cotton for surgical operations was recommended by him as early as 1861, and he proposed the employment of glycerine in order to keep photographic plates wet. He was appointed professor of mechanics in the Franklin institute in 1881, and non-resident professor of engineering practice in Stevens institute of technology in 1888, both of which chairs he still (1888) holds. The order of St. Olaf was conferred on him by the king of Sweden in 1877, and the degree of doctor of engineering by Stevens institute in 1888. He was president of the Franklin institute during 1870-'5, and of the American society of mechanical engineers in 1884, and he has also held that office in the Pennsylvania society for the prevention of cruelty to animals and the Photographic society of Philadelphia. He is a member of other learned societies both at home and abroad. Mr. Sellers was chosen a member of the Seybert commission to investigate the claims of Spiritualists, owing to his knowledge of sleight-of-hand, having been an expert in the practice of that art from his childhood. He was American correspondent of the "British Journal of Photography" in 1861-'3, and, in addition, contributed many papers to technical journals.