SELLERS, William, mechanical engineer, b, in Upper Darby, Pennsylvania, 19 September, 1824. He was educated at a private school, and at the age of fourteen was apprenticed to his uncle, a machinist, with whom he remained for seven years. In 1845 he was called to the management of the shops of the Fairbanks and Bancroft machine-works in Providence, Rhode Island, and two years afterward he established himself independently in Philadelphia. He was then joined by his former employer, and in 1848 the firm of Bancroft and Sellers was formed, which continued until 1855, when, on the death of the senior member, the style became William Sellers and Co. Mr. Sellers has been active in the improvement of existing forms of tools and machines, as well as in the invention of new patterns, and from his first patent, for an improvement on turning-lathes in 1854, until 1888 he has received seventy patents. His inventions have received numerous medals, and at the World's fair in Vienna in 1873 he was awarded a grand diploma of honor. In 1868 he established the Edgemoor iron company, which now owns the largest plant in this country for building iron bridges and other structures of iron and steel. All of the iron-work for the buildings of the World's fair in Philadelphia in 1876 were supplied by this company. He became president of the Midvale steel-works in 1873, and reorganized that concern, which is now one of the largest establishments in the vicinity of Philadelphia. Mr. Sellers was elected president of the Franklin institute in 1864, and while holding that office proposed the first formula that was ever offered for a system of screws, threads, and nuts, which subsequently became the standard for the United States. He is a member of scientific societies both in this country and abroad, was elected to the American philosophical society in 1864, to the National academy of sciences in 1873, and correspondent of the Societe d'encouragement pour l'industrie nationale in 1875. At the formation of the Fairmount park commission in 1867 he was appointed a commissioner for five years, during which time all of the land now comprised in this great park was purchased by the commission. He was active in the organization of the World's fair in Philadelphia in 1876, and was at the beginning vice-president of the management. In 1868 he was elected a trustee of the University of Pennsylvania, and he is a director of several railroads. His publications include short papers and discussions on technical subjects.