The two plants which gave Philadelphia its great reputation for tool building were those established by Sellers and Bement. Probably no one has had a greater influence on machine tools in America than William Sellers. He has been called the Whitworth of America, and there is a singular parallelism in the work and influence of the two men. Sellers was born in Pennsylvania in 1824, was educated in a private school maintained by his father, and later apprenticed to his uncle, John M. Poole, at Wilmington, Del.[207] When only twenty-one he took charge of the machine shop of Fairbanks, Bancroft & Company in Providence, R. I. Three years later he began the manufacture of machine tools and mill gearing at Thirtieth and Chestnut Streets, Philadelphia, and was soon after joined by Edward Bancroft, who moved from Providence, the firm becoming Bancroft & Sellers. John Sellers, Jr., a brother of William, became a partner and in 1853 they moved to Sixteenth Street and Pennsylvania Avenue. Mr. Bancroft died in 1855 and the firm became William Sellers & Company, which was incorporated in 1886, with William Sellers as president. [207] _Journal of the Franklin Institute_, Vol. CLIX, pp. 365-383. Bancroft was the inventive member of the firm and Mr. Sellers the executive. Sellers’ designing ability did not develop until after Bancroft’s death. His first patent was granted in 1857. In all he was granted over ninety United States patents and many others in foreign countries, covering a wide variety of subjects; machine tools of all kinds, injectors which he introduced into the United States, rifling machines, riveters, boilers, hydraulic machinery, hoisting cranes, steam hammers and engines, ordnance, turntables, etc. One of the best known and most original of Sellers’ machines was the spiral geared planer patented in 1862, which has always been associated with his name. Almost from the first Sellers cut loose from the accepted designs of the day. He was among the first to realize that red paint, beads and mouldings, and architectural embellishments were false in machine design. He introduced the “machine gray” paint which has become universal; made the form of the machine follow the function to be performed and freed it from all pockets and beading. Like Bement he realized that American tools then being built were too light; and they both put more metal into their machines than was the practice elsewhere. From the first he adopted standards and adhered to them so closely that repair parts can be supplied today for machines made fifty years ago.