31. Dutartre also exhibited a machine for printing in two colours, for which he received the silver medal. Others were exhibited for printing newspapers ; but their rapidity was not equal to ours, as it appears from the report, 6000 sheets perfect being the highest number stated ; but several ingenious adaptations and movements are noticed in Mr. Fairbairn's report.
In England, however, the demands of the newspaper press had not been met by even such improved machines as above described. The Times' could not be produced sufficiently early at the rate of 5000 or 6000 an hour. Mr. Applegath again employed his inventive faculty,* and produced a printing-machine on the vertical cylindrical system, which could produce on one side from 10,000 to 13,000 copies an hour. With such machines the `Times' has been worked since 1848; and the machine has been used for the production of the ' London Illustrated News,' and ether newspapers having a large circulation.
In this machine a central drum 200 inches in circumference, or 64 inches in diameter, turns on a vertical axis. We copy the following description from C. Tomlinson's `Cyclopedia of Useful Arts and .Manu factures' :—" The inking-table and the columns of type are secured to the surface of this drum ; the columns of type are placed vertically, not conforming to the curve of the drum. This is contrived in the following manner. A slab of iron is curved on its under side, so as to fit the large cylinder, while its upper-surface is fitted into facets, or flat parts, corresponding in width and number to the width and num ber of the columns of the newspaper. Between each column there is a strip of steel, with a thin edge, to print the rule,' the body of this strip being wedge-shaped,so as to fill up the angular space left between the columns of the type, and to press the type together sideways, or in the direction of the lines ; the type is pressed together in the other direction by means, of screws, and is firmly held together. The surface of the type thus forms a portion of a polygon, as already noticed ; and the regularity of the impression is obtained by pasting slips of paper on the paper cylinder. The large central drum is surrounded by eight cylinders, each about 13 inches in diameter, also with vertical axes. They are covered with cloth, and upon them the paper to be printed is carried by means of tapes. Each of these cylinders is so connected with the central drum, by means of toothed wheels, that the surface of each must move with the same velocity as the surface of the drum. It will thus be evident that if the type on the drum be inked, and each of the cylinders be supplied with a sheet of paper, a single revolution of the drum will cause the eight cylinders to revolve also, and produce an impression on one side of each of the sheets of paper. But for this purpose it is necessary that the type be inked eight times during one revolution of the drum. This is accomplished by means of eight sets of inking-rollers—one for each paper-cylinder. The ink is held in a vertical reservoir (supplied from above), formed of a duct,or roller, against which rests the two straight edges connected at the back, so as to prevent the ink running out. It is conveyed from the ductor roller by one of the inking-rollers in the following manner :—As tho inking-table on the revolving drum passes the ductor-roller, it receives from it a coating of ink, and then coming immediately in contact with the inking-rollers, it inks them ; the types next follow and receive from the inking-rollers their coating of ink ; and the drum, still revolving, brings the inked type into contact with the paper-cylinders, and the sheet is printed. It must not be forgotten, as one of tho distin
guishing features of this machine, that the various processes which have just been enumerated for one set of inking rollers and one paper cylinder are repeated eight times for every single revolution of the central drum, so that in this period eight sheets are printed and turned out of the machine. For this purpose it is necessary to supply the eight cylinders each with a sheet of paper. Over each cylinder is a sloping desk, upon which a number of sheets of white paper are placed. The layer-on stands by the side of this desk, and pushes forward the paper a sheet at a time toward the tape-fingers of the machine. These tapes seize it and draw it down in a vertical direction, between tapes, in the eight vertical frames, until its vertical edges correspond with the position of the form of type on the drum. When in this position its vertical motion is arrested for a moment ; it then moves horizon tally, and is carried towards the printing cylinder by the tapes. Passing round this cylinder, It is instantly printed. It is then con veyed horizontally, by means of tapes, to the other side of the frame, and is moved along to another desk, where the taker-off pulls it down. As soon as the sheet is thus disposed of, accommodation is made for another; and as each layer-on delivers to the machine two sheets every five seconds, sixteen sheets are thus printed in that brief space; and this is continued for any length of time, supposing no accident occurs, such as a sheet going wrong, in which case it is the duty of the taker off to pull a bell-handle, and the machine is instantly stopped by the engine-man. As the type-form on the central drum moves at the rate of 70 inches per second, and the paper to be printed moves at the same rate, if by any error in the delivery and motion of a sheet of paper it arrive at the printing cylinder 1-70th of a second too soon or too late, the relative position of the columns on one side as compared with those on the other side of the paper will be out of register by 1-70th of 70 inches,—namely, one inch,—in which ease the edge of the printed matter on one side will be an inch nearer to the edge of the paper than on the other side All the layer-on has to do is to draw forward the sheets so as always to have the edge of one ready for the machine to take in. If the steam-engine which works the machine be put on a greater speed, the central drum, and all the attendant appa ratus, would work with greater rapidity ; and such a speed might easily be obtained as to render it impossible for the layers-on to pre sent the paper fast enough to satisfy the improved appetite of the machine ; but in any case the machine would not take in the sheets as the layers-on choose to present them, but only at those periods, rapidly recurring though they be, which are provided by the peculiar functions of the machine." Another machine, likewise on the vertical principle, has been invented by the Messrs. Hoe, of America, and several of these have been brought into use in London.