more to manufacture. By 1853, there was evidence that interchangeable parts, then perfected by the Federal Armories, led to savings. The Ordnance Department freely shared the techniques used with outside suppliers. Eli Whitney and an early attempt In the US, Eli Whitney saw the potential benefit of developing "interchangeable parts" for the firearms of the United States military. In July 1801 he built ten guns, all containing the same exact parts and mechanisms, then disassembled them before the United States Congress. He placed the parts in a mixed pile and, with help, reassembled all of the firearms in front of Congress, much as Blanc had done some years before. The Congress was captivated and ordered a standard for all United States equipment. The use of interchangeable parts removed the problems of earlier eras concerning the difficulty or impossibility of producing new parts for old equipment. If one firearm part failed, another could be ordered, and the firearm would not need to be discarded. The catch was that Whitney's guns were costly and handmade by skilled workmen. Charles Fitch credited Whitney with successfully executing a firearms contract with interchangeable parts using the American System, but historians Merritt Roe Smith and Robert B. Gordon have since determined that Whitney never actually achieved interchangeable parts manufacturing. His family's arms company, however, did so after his death. Brunel's sailing blocks Mass production using interchangeable parts was first achieved in 1803 by Marc Isambard Brunel in cooperation with Henry Maudslay and Simon Goodrich, under the management of (and with contributions by) Brigadier-General Sir Samuel Bentham, the Inspector General of Naval Works at Portsmouth Block Mills, Portsmouth Dockyard, Hampshire, England. At the time, the Napoleonic War was at its height, and the Royal Navy was in a state of expansion that required 100,000 pulley blocks to be manufactured a year. Bentham had already achieved remarkable efficiency at the docks by introducing power-driven machinery and reorganising the dockyard system. Marc Brunel, a pioneering engineer, and Maudslay, a founding father of machine tool technology who had developed the first industrially practical screw-cutting lathe in 1800 which standardized screw thread sizes for the first time, collaborated on plans to manufacture block-making machinery; the proposal was submitted to the Admiralty who agreed to commission his services. By 1805, the dockyard had been fully updated with the revolutionary, purpose-built machinery at a time when products were still built individually with different