All of these matters emphasize the fact that the mutual interests of the capitalist who manufactures and sells, and of the employee by the efforts of whose hand and brain the products are being turned out, are each year being recognized and in a very large majority of cases are being acted upon in good faith. =Methods of Modern Manufacturing.= In former times, machines were built one at a time or in very small lots. Parts were made and fitted to the particular machine to which they belonged; and while the same general form and dimensions were practically maintained, there was no attempt made to render the several parts so exact as to fit upon any other machine than the one for which they were intended. Systems of gauges had not been developed, and the planer was yet a comparatively new tool; much work was still done by hand, the hammer, the cold chisel, and the file being the chief reliance of a large majority of machinists. This was the state of the machine shop and its methods nearly up to the year 1800. =Interchangeable Manufacturing.= The use of milling cutters and the commencement of practically interchangeable manufacturing, came into machine shop practice at nearly the same time. It has been said that "but for the milling machine, there would have been no such thing as interchangeable manufacturing." It might be said with quite as much truth, that if the system of interchangeable manufacturing had not been conceived, there would have been little need for the milling machine. Each, to a great extent, depended very much upon the development of the other──and upon a third factor, the conception and development of the method of handling work (particularly small parts) in jigs and fixtures. Milling cutters were made in America by one of the early machinists, a Frenchman named Vaucanson, who died in 1782. A sample of these had a hexagonal instead of a round hole, and the pitch of the teeth was very fine, so that the cutter resembled a saw rather than those at present in use. It is said that a man by the name of Bodmer, in Manchester, England, had made a milling machine in 1824. It is altogether probable that Eli Whitney, the inventor of the cotton gin, had built and used milling machines previous to this date, as the following item of mechanical history would seem to indicate. In January, 1798, Eli Whitney received from the United States Government an order to furnish ten thousand muskets, of which four thousand were to be delivered in one year, and the balance in two years. Mr. Whitney went at the undertaking in a very thorough and systematic manner. He first developed a water power; then erected suitable buildings; considered and developed ways and means for a larger and better product than had previously been realized; designed and built machinery to effect it; and trained workmen to a degree of skill necessary to success in their new employment.