The corrector takes a sharp tool, and punches a hole through the plate where the interloper is, just the size of the type, and then restoring a common type _e_, through the opening, cuts it off even at the back of the plate, and solders it in its place with lead. In this way a whole line of type is sometimes introduced for an incorrect line in the plate. The corrections being made, the plate is ready for the press. When not in use, the plates, being very valuable, are carefully put in a box,--a large book requiring several boxes. They are stored in fire-proof safes, made for this purpose. While books are generally stereotyped, woodcuts are always electrotyped. Instead of being moulded in plaster, the cut or illustrated page goes into the electrotype room, to be moulded in wax. [Illustration: Moulding in Wax.] Let us look at the process. A brass case, or very shallow, oblong pan is filled with liquid beeswax, which stands until it has hardened. The form containing the pages of type, well covered with fine black lead, is placed upon the bed of the press, shown in the picture; the face of the type is uppermost. There is an upper bed, which in the picture is swung half-way back. This is swung all the way back, and upon it is secured the brass case of wax. When the upper bed is brought back again, the wax face will of course be downward, and thus will be ready to receive an impression from the form of type resting on the lower bed; this lower bed is movable, and is gently raised by a screw until it presses into the wax, after the press is tightened, and now the soft wax receives the exact impression of the type; and the upper bed being swung back, the brass case, with its wax mould, is removed. We have got just as far, in fact, as when the plaster in stereotyping was ready to receive the casting. In the battery, a corner of which is seen in the picture, are hung one, two, three, or more copper plates; and from rods running parallel are hung the cases containing the wax moulds, one being hung on either side of the brass plate facing it. The positive pole is attached to the case, the negative to the copper plate; and the connection being made, a thin film of copper appears on the surface of the mould. This coating increases the longer the mould remains in the battery. After ten or twelve hours it is removed, and the result is a shell, as it is called, of the thickness of thin pasteboard, the upper surface a perfect _fac simile_ of the original page of type or wood-cut, every line, and every imperfection too, being reproduced. The under surface is exactly parallel; for each projection on the upper surface there is an indentation in the lower. [Illustration: The “Guillotine.”]