A machine for driving piles into the ground, to make a solid foundation for buildings, the construction of piers, wharfs, etc. As these engines are of every-day observation, and are figured in all previous works of this nature, we shall confine ourselves to a brief verbal description. By means of the mechanism of a common crane, a heavy iron weight, called the ram, is raised perpendicularly between two lofty guides of timber, framed together at the top and laterally, clear of the ram. Just as the ram attains to its highest elevation, a projecting lever from the hook to which the ram is suspended meets with a fixed obstruction to its upward passage, that bends the lever downwards, and thus unhooks the ram, which, falling from a great height, strikes the head of the pile with tremendous force, driving it into the ground. The hook and chain now descend, and the hook, coming in contact with the top of the ram, locks itself thereto again by means of a spring or lever-cacth, when it is drawn up again to repeat the operation.