“It was the understanding and expectation of the Secretary of the Treasury, with whom I contracted, that I should establish a manufactory on the principles which were then pointed out and explained to him. This system has been uniformly pursued from the beginning.”[160] [160] Blake, p. 300. It would seem that the stipulation in North’s contract of 1813 was not so much the beginning of a new method as a recognition of methods which had already come into existence. It seems almost inevitable that the two men, pioneer manufacturers and government contractors in closely allied industries, and located but twenty miles apart, must have known more or less of each other’s work and have been influenced by each other’s methods. Without trying to differentiate the credit between them too closely it is quite certain that in the work of these two men the interchangeable system had its birth. Colonel North’s work for the Government was invariably well done, and for more than fifty years he continued to supply, first pistols, and later rifles for the army and navy. Of the two, Whitney had the greater influence in spreading the interchangeable system throughout the country. He was well known and influential through his invention of the cotton gin and was located in a larger center. He was called upon by the Government for advice, and at its request sent to Springfield some of his best workmen to introduce his system there, and also help to start it at Harper’s Ferry. Whitney built his factory in 1798 or 1800, and employed at the start about sixty men. Colonel North moved from Berlin to Middletown in 1813, and built a factory at a cost of about $100,000, where he employed seventy men and produced about thirty pistols a day. The interchangeable system was well begun in both of these factories by 1815. The Springfield armory had been started during the Revolution, mainly for making cannon. In 1792 Congress authorized the President to establish two arsenals for small arms. These were located at Springfield in the North, and Harper’s Ferry in the South. In 1811 Captain Hall was granted a patent for a gun which was adopted as the government standard in 1819 and the Government undertook to manufacture them at one of its own armories. Captain Hall was placed in charge of the work and the plant at Harper’s Ferry was equipped for interchangeable manufacture.[161] Later many of these rifles were made by private contractors, such as Colonel North. By 1828 in one of Colonel North’s contracts we find the principle of interchangeability extended still further. It is guaranteed that the component parts should be interchangeable, not only in the lot contracted for, but that they may be exchanged in a similar manner with the rifles made or making at the national armories.[162] [161] “Memoir of Simeon North,” pp. 168-169. [162] _Ibid._, p. 160.