At least two attempts were made to manufacture guns interchangeably in France, one in 1717, the other in 1785. Of the first we know little. Fitch, in his “Report on the Manufactures of Interchangeable Mechanisms,” in the United States census of 1880, speaks of it, but says it was a failure.[149] We know of the second from an interesting and surprising source. Thomas Jefferson, while Minister to France, wrote a letter to John Jay, dated August 30, 1785, which contains the following: [149] p. 2. An improvement is made here in the construction of muskets, which it may be interesting to Congress to know, should they at any time propose to procure any. It consists in the making every part of them so exactly alike, that what belongs to any one, may be used for every other musket in the magazine. The government here has examined and approved the method, and is establishing a large manufactory for the purpose of putting it into execution. As yet, the inventor has only completed the lock of the musket, on this plan. He will proceed immediately to have the barrel, stock, and other parts, executed in the same way. Supposing it might be useful in the United States, I went to the workman. He presented me the parts of fifty locks taken to pieces, and arranged in compartments. I put several together myself, taking pieces at hazard as they came to hand, and they fitted in the most perfect manner. The advantages of this, when arms need repair, are evident. He effects it by tools of his own contrivance, which, at the same time, abridge the work, so that he thinks he shall be able to furnish the musket two livres cheaper than the common price. But it will be two or three years before he will be able to furnish any quantity. I mention it now, as it may have an influence on the plan for furnishing our magazines with this arm.[150] [150] “The Writings of Thomas Jefferson,” Edited by H. A. Washington, Vol. I, p. 411. New York, 1853. Six months later he wrote a letter to the governor of Virginia, which is almost a copy of this one. In another letter written many years later to James Monroe, Jefferson gives the name of this mechanic as Le Blanc, saying that he had extended his system to the barrel, mounting and stock, and stating: “I endeavored to get the U. S. to bring him over, which he was ready for on moderate terms. I failed and I do not know what became of him.”[151] We wish to give full credit to this genius who seems to have caught a clear idea of some at least of the principles involved, those of interchangeability and the substitution of machine work for hand work. The account makes no mention of gauges or of the division of labor, but this might easily have been due to Jefferson’s unfamiliarity with the details of manufacture. [151] “The Writings of Thomas Jefferson,” Edited by Paul L. Ford, Vol. VIII, p. 101. New York, 1887.