1851 Great Exhibition: Official Catalogue: Class VI.: Edward Cowper
134. COWPER, EDWARD, F.R.S., King's College, London, and 9 Kensington Park Road, Notting Hill — Inventor and Patentee.
Model of the printing machine now in general use. The Catalogue of the Exhibition is printed by these machines. The model was made by T. B. Winter, Esq., a student in King's College, London.
[The following is a brief review of the progress of printing by machinery:— In 1790, Nicholson proposed placing both the types and paper upon cylinders, and also distributing and applying the ink by means of cylinders. Another plan was to place the types upon a table, and the paper upon a cylinder, and to cause the table and type to pass backward and forward under the paper cylinder. In 1813, Donkin and Bacon proposed placing the types upon a prism, and causing it to revolve against an irregular-shaped cylinder upon which the paper was placed. Neither of the above machines came into use, but in the latter, Donkin introduced the "composition" inking rollers (i.e. elastic rollers, made of treacle and glue), for distributing and applying the ink. In 1814, Koenig made the first working machine, and erected two of them at the office of "The Times" newspaper, each of which produced 1,800 impressions per hour, and they continued in use until 1827; he also made two machines for Mr. Bensley, one producing 800 impressions per hour, and the other printing 800 sheets, both sides, per hour. In 1816, Cowper made machines to print from curved stereotype plates, and in 1818, one to print from ordinary type. These machines printed from 800 to 1,000 sheets on both sides, or from 2,000 to 2,400 impressions on one side of the sheet. Machines to print only one side are generally called newspaper machines, and machines to print both sides are called book machines.]
The cut represents one of these book machines; it consists of a cast-iron frame, about 14 feet long and 4 feet wide, in which an iron table slides backward and forward, passing in its progress under two cast-iron cylinders, called the paper cylinders. Two sets of type, technically called the form, are fixed on the table at such a distance from each other that one form passes under one cylinder and the other form under the other cylinder, the sheet of paper being held on the cylinder by means of tapes. At each end of the machine is a reservoir, or trough, of ink, the trough being made by an iron roller, about 3 inches diameter, turning in contact with a flat iron bar, which only allows a very small quantity of ink to pass; this iron bar is the abductor, but is commonly called the "doctor," and the iron roller the "doctor" roller. An elastic composition roller is made to vibrate between the table and the abductor roller, and conveys the ink from the latter to the table.
A number of composition rollers are placed across the table, their axes resting in notched bearings. As the table passes backward and forward under these rollers, the ink deposited by the vibrating roller becomes very evenly spread upon the table. This spreading, or distribution, as it is called, is effected by three or four of the rollers (called the "distributing rollers") not only having a motion round their axes, but also a motion in the direction of the length of their axes, i.e., in an end motion. This motion was produced in Mr. Cowper's first machines by giving an end motion to the frame, which supported the distributing rollers. Mr. Applegath suggested the more simple mode of placing the rollers in a diagonal or sloping position across the table, and making the axis long enough to slide in their notches. Three or four other rollers, called the "inking rollers," have no end motion; their office is to take the ink up from the table, and apply it to the types. Thus the "taking," "distributing," and "inking" is all done by the machine itself.
The sheet of paper is laid by a boy on a web of tapes, whence it is carried forward, and enters between two sets of tapes; and as these tapes are carried round one paper cylinder, and then over and under two wooden "drums" to the other paper cylinder, the sheet of paper necessarily travels with the tapes, and the sheet is thus conveyed from one paper cylinder to the other; in the course of its progress, the sheet is turned over, receiving one printed impression on one side from the first form, and the second impression on the other side of the sheet from the second form, and as the tapes leave the second cylinder they divide, and the printed sheet falls into the hands of another boy.
The machines are commonly known as "Applegath and Cowper's machines."
[Mr. Napier's machine differs from Applegath and Cowper's: his machine is described in a separate article. In 1827, Cowper and Applegath jointly invented the four-cylinder machine, which Applegath erected for printing "The Times" newspaper. It at once superseded Koenig's machines, which were taken down. This machine printed from 4,000 to 5,000 impressions per hour. The diagram will give a general idea of these machines, which are still in use at The Times" office.
They consist of a table, moved backwards and forwards under four iron cylinders (called the paper cylinders), about 9 inches in diameter, which are covered with cloth, and round which the sheets of paper are held between tapes. The form is fixed on one part of the table, the inking rollers lying on another part, on which they distribute the ink. Some of these rollers are placed in a diagonal position on the table, so that, as it moves backwards and forwards, they have a motion in the direction of their length, called the " end- motion," which, combined with the rotatory motion, causes the ink to be more effectually distributed. The ink is held in a reservoir or trough formed of an iron roller, called the ductor, against which the edge of an iron plate rests, and, by its pressure, regulates the quantity of ink given out. The ink is conveyed from the ductor-roller to the table by means of an elastic roller vibrating between them. The feeding is performed by four " layers-on," who lay the sheets of paper on the feeding boards, whence they enter the machine between three pairs of tapes, by which they are conveyed round the cylinders, and thence to the spot where the "takers-off" stand, into whose hands the sheets fall as the tapes separate.
The last great improvement in rapid printing was invented by Mr. Applegath, in May 1848, when he erected at "The Times" office two vertical cylinder machines, each producing 10,000 sheets per hour.]