EN'VELOPES. Until the introduction of the penny-postage system, E. for written letters were very little adopted; it was far more customary to secure, by wafer or sealing-wax, the sheet of paper on which the letter was written. When the postage was rendered uniform for all distances, and prepayment enforced, or at least recommended, it was supposed that stamped E. would be convenient coverings for letters, sealing the letter and paying the postage at one operation. Such has indeed been the case; but the envelope-manufacture has since taken a new direction, and to an extent that no one could have contemplated. Several large firms in London and elsewhere can make E. more cheaply than the government, and can vary the size, shape, color, and quantity to an indefinite degree; as a consequence, although E. bearing the government impressed stamp are stilll in demand, the uristamped varieties are used in very much larger quantities. They are made by two methods, involving different amounts of machine-power. The paper is first cut into quadrangular pieces rather longer than wide, by a cutting blade brought to bear Ilion a pile of sheets at once; and then cutting dies reduce these pieces to the proper shape, generally lozenge or diamond form, but sometimes with curvilinear edges. For sonic kinds, it is found to economize both time and paper to stamp the pieces out at once from the rough sheets. The subsequent fold ing and gumming are performed generally by hand, sometimes by machine. In the hand-method, women and girls fold with almost incredible quickness, having very simple guide-pieces to aid them in giving the proper oblong quadrangular shape to the fold. The gum is applied with a small brush, either along the overlapping edges, or in spots here and there, according to the quality of the envelope.
The envelope-machines, however, such as those of Messrs. De In Rue, are beautiful examples of automatic mechanism. In the kind invented and used by this celebrated firm, a cutting-machine severs the blanks or papers; and dies are employed to stamp the device on the spot where the seal would otherwise lie. The blanks are then fed into the folding-machine, where they pass through a curious series of processes. Each blank is carried down into a box, where a plunger makes four creases in it; two short levers fold down two of the flaps thus made; a gumming apparatus comes up, and applies a line of wet gum to each flap-edge; two small levers then fold down the other two flaps (but only fastening one of them); and finally, the envelope is shifted aside to a pile, and makes way for another. All thee processes are gone through in one second, enabling the machine to make 60 E. per minute. Where 12 of these machines are work ing at once, it will be seen that a million E. are put out of hand in a very short time. Nearly a million and a half of enveloped letters pass through the post every day in the United Kingdom, most of the E. for which are of home manufacture; and besides this, a large export trade is maintained. The stamped E. all go to Somerset house, to have the stamp impressed upon them, which is done by a beautiful machine, chiefly invented by Mr. Edwin Flill, in which embossing and color-printing are ingeniously combined. These E. are sold by the stamp-office, between which and the post-office a monetary adjustment becomes necessary.