I saw also, in company with Messrs. Vaux and Niederstetter, the mine of the United States, which is established here. In the year 1793, when Philadelphia was still the seat of government of the United States, this mint was located in the newly-built private house, and it is as yet the only one in the United States. The processes in this mint are very simple, and but a few improvements are yet adapted, which so greatly distinguish the mints of London and Milan. They were doing but little when we came; we saw nothing but the stretching of the bars of silver between cylinders, like those in the rolling mills at Pittsburgh, and the stamping of the pieces, which was done by means of a contrivance similar to that by which rivet-holes are made in the iron plates for steam-engine boilers. We saw, moreover, the cutting of half dollar pieces, which is done by means of a stamp, worked by two men. A third stands by to place the uncoined pieces in a box, which are then brought under the stamp by a particular contrivance. After they are coined, they fall by means of this contrivance into a box which stands below. Since 1803, no larger silver coins are made than half dollars, as the dollars were immediately bought up and exported to China for trade, because the….