Automatic Typewriters.—The automatic typewriter is de signed to produce actual typewritten letters at three times the average speed of a typist. Its mechanical movements are con trolled by a paper roll, similar to that of a player-piano, in which perforations representing characters on the typewriter keys are made by a perforator. When an entire letter has been thus per forated, the paper is cut from the roll, and its ends are cemented together to form an endless belt, which is then placed over the drum of the automatic typewriter. The operator writes by hand the name and address and starts the automatic device. Pins dropping through the perforations into slots, as the roll is carried forward by the revolution of the drum, actuate the typewriter keys, causing the typing of the words; when all the perforations have passed over the drum, the operator removes the finished letter and then repeats. Insertions of special words or sentences may be made by hand at any desired point.
Photocopying Machines.—A special photographic machine, in which a roll of sensitised paper coated on rag stock is used as a negative, photographing directly without the intervention of plates, has of late years been highly developed and used exten sively as an office device. It offers a means of quickly producing a fac-simile copy of any document, and has therefore to a great extent eliminated the laborious hand copying of records, deeds, insurance applications, contracts and the like. The equipment consists of a large camera combined with a developing machine, so that after an exposure is made the sensitised paper is carried first to the developing bath and then to the fixing bath. Dials and levers controi all operations, and the machine is so scientif ically adjusted that an office boy can turn out perfect copies. The colours are reversed in the first print, called a "black print"; that is, the whites in the original are black and the blacks are white. As the photograph is made through a reversing prism, the letters appear exactly as in the original. A white positive print is made by re-photographing the black print. By continuing to photograph the original, as many black prints as desired can be made; and as many positives as required can be made by photo graphing the black prints. It is also possible, by using a special kind of paper, coated on both sides, to print two sides of a page simultaneously and have the photograph with an image on each side.
Addressing Machines.—These are in reality devices designed for duplicating small pieces of writing. Originally designed for duplicating names and addresses—hence the name—they now have many other uses, such as the making of invoices, state ments, receipts and other office records. They are of especial
value in businesses where the same list of names and addresses must be repeatedly used. Each name and address must first be impressed upon a metal plate, cut on a fibre stencil or set in type, according to the character of the machine. The metal plate is prepared by an embossing machine operated by hand or electric motor; a blank plate is inserted in the machine, and the required characters are selected by an indicator and stamped into the metal. Some embossers have a typewriter keyboard, the embossing being performed by depressing the keys. Some metal plates carry a name card and others a record card for recording relevant data. A fibre stencil consists of a frame in which is mounted a panel of semi-transparent paper coated with a gelatin ous material, some frames having spaces for the insertion of relevant data. The name and address are cut by means of a typewriter from which the ribbon has been removed, a special device holding the stencil while it is cut. When printer's type is used, names and addresses are cast on a linotype machine.
Addressing machines, despite many structural differences, oper ate on the same general principle. The metal plates, stencils or slugs are fed from a magazine to the printing point where the envelope or other matter to be addressed is placed either by hand or by a mechanical device. Directly over the printing point is a stamping arm which comes down on the envelope when the machine is operated, thereby bringing it into contact with the plate, stencil or slug either directly, in case ink is used, or through a ribbon. As the arm rises, another plate comes to the printing point, the one just used passing to a receiving machine, where it re-files itself in original order. Models are hand, foot treadle or motor operated, the speed varying from i,000 to 15,000 impressions an hour. Special models are designed for publishers addressing on large envelopes, on mailer strip or directly on the margins of newspapers and magazines. The adaptability of addressing machines is greatly increased by attachments, some of which are so common as to be considered standard equipment. The metal plates and fibre stencils are filed like index cards in drawers kept in cabinets, slugs being filed in galleys and stored in cabinets. One machine is unique in that its metal plates are linked together to form an endless chain; they pass to the print ing point from a reel on which they are wound and they are then re-wound on another reel, the reels being stored in cabinets.