A successful machine which Spencer invented for turning sewing machine spools suggested to Spencer the possibility of making metal screws automatically. The result was his invention of the automatic turret lathe. The importance of the blank cam cylinder, with its flat strips adjustable for various jobs, was wholly over-looked by his patent attorney, with the result that Spencer obtained no patent right on the most valuable feature in the whole machine. The importance of this invention can hardly be overestimated. It ranks with Maudslay’s slide-rest and the turret tool-holder, as it is an essential feature in all modern automatic lathes, both for bar-stock and chucking work. Assured of the success of the machine, Spencer withdrew from active connection with the Billings & Spencer Company in 1874, and in 1876, with George A. Fairfield, then superintendent of the Weed Sewing Machine Company, and others, formed the Hartford Machine Screw Company, one of the most successful enterprises in the city. Unfortunately, Mr. Spencer withdrew in 1882 to manufacture a new repeating shotgun and rifle which he had invented. The gun was a success mechanically, but the Spencer Arms Company, which had been formed in 1883 at Windsor, Conn., was a failure, and Mr. Spencer lost heavily. In his later years Mr. Spencer has returned to the field where he did his most brilliant work, automatic lathes. He represents the New England mechanic at his best, and his tireless and productive ingenuity has made a permanent impress on modern manufacturing methods. Francis A. Pratt was born at Woodstock, Vt. When he was eight years old his family moved to Lowell. He was a mechanic from boyhood but he had the good fortune to be apprenticed as a machinist with Warren Aldrich, a good mechanic and a wise teacher. At twenty, Mr. Pratt went to Gloucester, N. J., where he was employed first as a journeyman, later as a contractor. In 1852 he came to the Colt shop, where he worked for two years. He then accepted the foremanship of the Phœnix Iron Works, which was run by Levi Lincoln and his two sons. Amos Whitney was born in Maine and moved to Lawrence, Mass., where he served his apprenticeship with the Essex Machine Company which built cotton machinery, locomotives and machine tools. He came from a family of mechanics. His father was a locksmith and machinist, his grandfather was an expert blacksmith, his great-grandfather was a small manufacturer of agricultural tools, and he is of the same family as Eli Whitney of New Haven, and Baxter D. Whitney, the veteran tool builder of Winchendon. In 1850 both he and his father were working at Colt’s factory at Hartford. In 1854 Amos Whitney joined Pratt in the Phœnix Iron Works, where they worked together for ten years, the former as a contractor, the latter as superintendent. Whitney was earning over eight dollars a day when he left Colt’s and took up the new contract work which offered at the beginning only two dollars a day.