As it is impossible in the limits of this paper to describe all the forms in which the movable fulcrum hammers have been arranged, two types only will be selected taken from actual work; namely, a small planishing hammer, and a medium-sized forging hammer.[1] [Footnote 1: To the makers, Messrs. J. Scott Rawlings & Co, of Birmingham, the author is indebted for the working drawings of these hammers.] The small planishing hammer, Figs. 1 to 3, next page, is used for copper, tin, electro, and iron plate, for scythes, and other thin work, for which it is sufficient to adjust the force of the blow once for all by hand, according to the thickness and quality of the material before commencing to hammer it. The hammer weighs 15 lb., and has a stroke variable from 2½ in. to 9½ in., and makes 250 blows per minute. The driving shaft, A, is fitted with fast and loose belt pulleys, the belt fork being connected to the pedal, P, which when pressed down by the foot of the workman, slides the driving belt on to the fast pulley and starts the hammer; when the foot is taken off the pedal, the weight on the latter moves the belt quickly on to the loose pulley, and the hammer is stopped. The flywheel on the shaft, A, is weighted on one side, so that it causes the hammer to stop at the top of its stroke after working; thus enabling the material to be placed on the anvil before starting the hammer. The movable fulcrum, B, consists of a stud, free to slide in a slot, C, in the framing, and held in position by a nut and toothed washer. On the fulcrum is mounted the socket, D, through which passes freely a round bar or rocking lever, E, attached at one end to the main piston, F, of the hammer, G, and having at the other extremity a long slide, H, mounted upon it. This slide is carried on the crank-pin, I, fastened to the disk, J, attached to the driving shaft, A. The crank-pin, in revolving, reciprocates the rocking lever, E, and main piston, F, and through the medium of the pneumatic connection, the hammer, G. The slide, H, in revolving with the crank-pin, also moves backward and forward along the rocking lever, approaching the fulcrum, B, during the down-stroke of the hammer, and receding from it during the up-stroke. By this means the velocity of the hammer is considerably accelerated in its downward stroke, causing a sharp blow to be given while it is gently raised during its upward stroke.