The machines represented in [figs. 923], [924], [925], are different forms of those which have been patented by Messrs. Applegath and Cowper. That shown in [figs. 923.] and [925.] prints both sides of the sheet during its passage, and is capable of throwing off nearly 1000 finished sheets per hour. The moistened quires of blank paper being piled upon a table A, the boy, who stands on the adjoining platform, takes up one sheet after another, and lays them upon the feeder B, which has several linen girths passing across its surface, and round a pulley at each end of the feeder; so that whenever the pulleys begin to revolve, the motion of the girths carries forward the sheet, and delivers it over the entering roller E, where it is embraced between two series of endless tapes, that pass round a series of tension rollers. These tapes are so placed as to fall partly between, and partly exterior to, the pages of the printing; whereby they remain in close contact with the sheet of paper on both of its sides during its progress through the machine. The paper is thus conducted from the first printing cylinder F, to the second cylinder G, without having the truth of its register impaired, so that the coincidence of the two pages is perfect. These two great cylinders, or drums, are made of cast iron, turned perfectly true upon a self-acting lathe;[47] they are clothed in these parts, corresponding to the typographic impression, with fine woollen cloth, called blankets by the pressmen, and revolve upon powerful shafts which rest in brass bearings of the strong framing of the machine. These bearings, or plummer blocks, are susceptible of any degree of adjustment, by set screws. The drums H and I are made of wood; they serve to conduct the sheet evenly from the one printing cylinder to the other.

[47] I have witnessed with much pleasure the turning of these great cylinders in Messrs. Cowper’s factory at Manchester.

[Fig. 925 enlarged] (351 kB)

One series of tapes commences at the upper part of the entering drum E, proceeds in contact with the right-hand side and under surface of the printing cylinder F, passes next over the carrier-drum H, and under the carrier-drum I; then encompassing the left-hand side and under portion of the printing drum G, it passes in contact with the small tension rollers a, b, c, d, [fig. 925.], and finally arrives at the roller E, which may be called the commencement of the one series of endless tapes. The other series may be supposed to commence at the roller h; it has an equal number of tapes, and corresponds with the former in being placed upon the cylinders so that the sheets of paper may be held securely between them. This second series descends from the roller h, [fig. 925.], to the entering drum E, where it meets and coincides with the first series in such a way that both sets of tapes proceed together under the printing cylinder F, over H, under I, and round G, until they arrive at the roller i, [fig. 923.], where they separate, after having continued in contact, except at the places where the sheets of paper are held between them. The tapes descend from the roller i, to a roller at k, and, after passing in contact with rollers at l, m, n, they finally arrive at the roller h, where they were supposed to commence. Hence two series of tapes act invariably in contact, without the least mutual interference, as may be seen by inspection of the [figs. 923], [924], [925.]