In the manufacture of wire, the metal from which it is to be made is first cast or wrought into an ingot (A, fig. 1); it is then passed between rollers (fig. 2) which flatten it into a sheet (B, fig. 1), which is next carried between other rollers (fig. 3) having their surfaces so cut that the projections on one of them fit into the hollows of the other, forming so many cutting edges or shears (fig. 4), from which the sheet of metal comes forth at A, fig. 3, cut into strips or square rods (C, fig. 1). These rods are then drawn with great force through a plate of hardened steel having a series of holes, gradually diminishing in size, bored through it, which is called the “draw-plate;” the wire (of whatever metal it be) has to be heated red-hot from time to time, to soften or “anneal” it, for the compression produced by the drawing so hardens it that it becomes brittle. A pair of nippers holds the end of the wire, and these are moved along a sort of bench by a “rack and pinion” (fig. 5). When all has passed the first hole, it is drawn through the second, and so on to the size required. When the wire is pretty fine, it is attached to a “cylinder,” which on turning round winds off the wire and at the same time draws it through the plate, as shown in the engraving, the wire being made to pass over a small charcoal fire previous to entering the draw-plate. Illustration: FIG. 5. (‡ RACK AND PINION.) Illustration: FINE WIRE DRAWING. Different metals have different powers of “ductility,” that is to say, some can be drawn much finer than others. Dr. Turner says, “The only metals remarkable in this respect are gold, silver, platinum, iron, and copper. Walliston devised a method by which gold wire may be obtained so fine that its diameter shall be only the 5000th part of an inch, and 550 feet of it are required to weigh one grain; he obtained a platinum wire so small that its diameter did not exceed the 30,000th of an inch. It is singular that the ductility and malleability of the same metal are not always in proportion to each other. Iron, for example, cannot be made into thin leaves, but it may be drawn into very small wires.” Illustration: FIG. 6. (‡ WIRE GAUGE.) The sizes of wires are ascertained by a small instrument called a “gauge,” which is a plate of steel with an opening diminishing to a point in it, and marks on the sides corresponding to the distance the wire will pass down the notch (fig. 6). CUTLERY. Illustration: FIG. 1. (‡ KNIFE BLADE.)