To the third question as to why this development when once begun should have been so rapid, there are probably two answers. First, an entirely new demand for accurate tools arose during these years, springing from the inventions of Arkwright, Whitney, Watt, Fulton, Stephenson and others. The textile industries, the steam engine, railways, and the scores of industries they called into being, all called for better and stronger means of production. While the rapidity of the development was due partly to the pressure of this demand, a second element, that of cumulative experience, was present, and can be clearly traced. Wilkinson was somewhat of an exception, as he was primarily an iron master and not a tool builder, so his relationship to other tool builders is not so direct or clear. But the connection between Bramah, Maudslay, Clement, Whitworth and Nasmyth, is shown in the “genealogical” table in Fig. 5. Bramah had a shop in London where, for many years, he manufactured locks and built hydraulic machinery and woodworking tools. Maudslay, probably the finest mechanician of his day, went to work for Bramah when only eighteen years old and became his foreman in less than a year. He left after a few years and started in for himself, later taking Field into partnership, and Maudslay & Field’s became one of the most famous shops in the world. Sir Samuel Bentham, who was inspector general of the British navy, began the design of a set of machines for manufacturing pulley blocks at the Portsmouth navy yard. He soon met Marc Isambard Brunel, a brilliant young Royalist officer, who had been driven out of France during the Revolution, and had started working on block machinery through a conversation held at Alexander Hamilton’s dinner table while in America a few years before. Bentham saw the superiority of Brunel’s plans, substituted them for his own, and commissioned him to go ahead. In his search for someone to build the machinery, Brunel was referred to Maudslay, then just starting in for himself. Maudslay built the machines, forty-four in all, and they were a brilliant success. There has been considerable controversy as to whether Bentham or Brunel designed them. While Maudslay’s skill appears in the practical details, the general scheme was undoubtedly Brunel’s. In a few of the machines Bentham’s designs seem to have been used, but he was able enough and generous enough to set aside most of his own designs for the better ones of Brunel.