A A, [fig. 759.], is the fly-wheel of an ordinary lathe, round which the endless cord B B passes, and embraces the pulley C, mounted upon the axle of the grindstone D. The flywheel is supported by a strong frame E E, and may be turned by a winch-handle, as usual, or by mechanical power. In the needle factories, the pointing-shops are in general very large, and contain several grindstones running on the same long horizontal shaft, placed near the floor of the apartment, and driven by water or steam power. One of the extremities of the shaft of the wheel A has a kneed or bent winch F, which by means of an intermediate crank G G, sets in action a double bellows H I, with a continuous blast, consisting of the air feeder H below, and the air regulator I above. The first is composed of two flaps, one of them a a, being fast and attached to the floor, and the other e e, moving with a hinge-joint; both being joined by strong leather nailed to their edges. This flap has a tail g, of which the end is forked to receive the end of the crank G. Both flaps are perforated with openings furnished with valves for the admission of the air, which is thence driven into a horizontal pipe K, placed beneath the floor of the workshop, and may be afterwards directed in an uninterrupted blast upon the grindstone, by means of the tin tubes N O O, which embrace it, and have longitudinal slits in them. A brass socket is supposed to be fixed upon the ground; it communicates with the pipe K, by means of a small copper tube, into which one of the extremities of the pipe N is fitted; the other is supported by the point of a screw Q, and moves round it as a pivot, so as to allow the two upright branches O O, to be placed at the same distance from the grindstone. These branches are soldered to the horizontal pipe N, and connected at their top by the tube P.
The wind which escapes through the slits of these pipes, blows upon the grindstone, and carries off its dust into a conduit R, [fig. 759.], which may be extended to S, beyond the wall of the building, or bent at right angles, as at T, to receive the conduits of the other grindstones of the factory.
A safety valve J, placed in an orifice formed in the regulator flap I, is kept shut by a spiral spring of strong iron wire. It opens to allow the superfluous air to escape, when, by the rising of the bellows, the tail L presses upon a small piece of wood, and thereby prevents their being injured.
The wires thus pointed at both ends are transferred to the first workshop, and cut in two, to form two needles, so that all of one quality may be of equal length. For each sort a small instrument, [fig. 760.], is employed, being a copper plate nearly square, having a turned up edge only upon two of its sides; the one of which is intended to receive all the points, and the other to resist the pressure of the shears. In this small tool a certain number of wires are put with their points in contact with the border, and they are cut together flush with the plate by means of the shears, [fig. 752.], which are moved by the knee of the workman. The remainder of the wires are then laid upon the same copper or brass tool, and are cut also even; there being a trifling waste in this operation. The pieces of wire out of which two needles are formed, are always left a little too long, as the pointer can never hit exact uniformity in his work.
These pointed wires are laid parallel to each other in little wooden boxes, and transferred to the head-flattener. This workman, seated at a table with a block of steel before him, about 3 inches cube, seizes in his left hand 20 or 25 needles, between his finger and thumb, spreading them out like a fan, with the points under the thumb, and the heads projecting; he lays these heads upon the steel block, and with a small flat-faced hammer strikes successive blows upon all the heads, so as to flatten each in an instant. He then arranges them in a box with the points turned the same way.
The flatted heads have become hardened by the blow of the hammer; when annealed by heating and slow cooling, they are handed to the piercer. This is commonly a child, who laying the head upon a block of steel, and applying the point of a small punch to it, pierces the eye with a smart tap of a hammer, applied first upon the one side, and then exactly opposite upon the other.