THE FORGES.
On the extreme right of the picture, and somewhat in the distance, may be seen another trip-hammer with a bar upon the anvil beneath it, this bar being suspended likewise from a crane. When the iron becomes too cold to yield any longer to the percussion, the hammer is stopped, the crane is swung round, and the iron is replaced in the forge to be heated anew; and at length, when heated, it is brought back again under the hammer as before.
The forging of shafts requires heavier machinery even than this. The enormous mass of iron that is in this case to be forged, is bricked up in a furnace to be heated, and remains there many hours. The masonry is then broken away and the red hot beam is swung round under the hammer, as seen below. It is suspended from the crane by heavy chains, and is guided by the workmen by means of iron handles clamped to it at a distance from the heated part, as seen in the engraving in the adjoining column. The hammer is lifted by means of the cam below it, as seen in the engraving below. This cam is a projection from an axis revolving beneath the floor, and which, as it revolves, carries the cams successively against a projection upon the under side of the hammer, which is partly concealed in the engraving by the figure of the man. When the point of the cam has passed beyond the projection it allows the hammer to fall.
HEATING A SHAFT.
FORGING A SHAFT.
While the process of forging such a shaft is going on, one man throws water upon the work, to effect some purpose connected with the scaling of the iron, while another, with an instrument called the callipers, measures the diameter of the shaft, to regulate the size, as the forging proceeds.
THE LATHES.