All the nail heads are now levelled with a rasp, the shoe istround and polished up with a composition of bees wax and ivory black, the upper leathers being brushed with a circular brush, and the shoes made ready for sale, except those which require to be bound and lined.
The machine for the long nails. The nails are cut from slips of sheet-iron, which is so cut, that when the nails are cut off from the end of the slips, the grain of the iron will be in the direction of the length of the nail.
In cutting the nails, the workman applies the iron with his hand, and draws the machine, by the action of his foot upon a treadle; the treadle drives a crank and heavy fly; from the crank there proceeds a rod to the longer end of a strong lever, whose axis is sup ported on pivots above the fly and the crank. A fix ed cutter being attached to the frame, a steal cutter, which acts against it, is fixed at a small distance from the centre of the lever, and at the opposite side of the axis to the long lever. This cutter is sharpened on the lower side, and the fixed one on the upper side. As the lever rises and falls by the revolution of the crank, the edge of the moveable cutter is brought close to that of the fixed one without touching it. The slip of iron being admitted between the cutters, a small portion of the end of it hangs over the edge of the fixed cutter, and is cut off into a nail by the de scent of the fixed cutter. On the ascent of the mo veable cutter, the strip of iron is pushed forward, and another nail is cut. The nails are narrow at the end which is to be the point, but at the other end they arc as broad as the thickness of the plate, so as to have a square figure. In the direction of the thickness of the
plate, they are as broad at the point as at the head, so that the nail is a small wedge instead of a pyramid. For this purpose the cut across the slip of iron is not perpendicular to the length of the strip of iron, but a little inclined to it; and as the inclination of the cut is reversed at every successive cut, the head of one nail is cut from the same side as the point of the next. The thickness of the nail is regulated by the quantity by which the extremity of the slip ,of iron projects over the edge of the fixed cutter, and the angle of in clination may be made to vary by two stops, against which the end of the slip bears. This is effected by a part projecting from the lever beneath the edge of the moving cutter, and curved to the arc of a circle described from the axis. This slip is as far behind the edge of the cutter as the thickness of the nail in tended to be cut off. The reversing of the cut is ef fected merely by turning the under side of the slip uppermost after every cut.
We have been induced to give this particular ac count of the shoe machinery, not merely from the in genuity displayed in its construction, but from the probability of its being, with some modifications, more extensively employed in various branches of the useful arts. Several of the machines above describ ed were executed by Mr. Henry Maudslay with that ingenuity and accuracy which characterise all his works.