CALICO-PRINTING 589 



the wheel 20 are made to pass, which renders proportionally, greater or less, tho 

 advance of the cloth at each movement ; and this is further regulated by a ratchet 

 wheel placed at D. At each half turn of this last, the lever 22 raises the catch or 

 pallet, and throws out of gear tho wheels 21 during the other half turn ; but as in the 

 working of these wheels there would be inevitably a backward movement, this is 

 prevented by a break, consisting of a pulley, mounted on the shaft of tho axis of the 

 wheel 20, and a brass wire which after making a turn and a half, or two turns, on this 

 shaft, is stretched by the weight 23, which offers a sufficient resistance to any recoil. 

 The slides or block-holders are put in motion by tho wheels 27 and 28, gearing with 

 the larger wheel 29. And to vary their action at pleasure, both for causing the 

 blocks to bear more or less strongly on tho sieves, so as to bd more or less charged 

 with colour, and likewise for attaining the exact pressure, which suits best for the 

 colour to be laid on, it is sufficient to more tho points of junction, 16 and 17, to a 

 greater or less distance from the point marked 15, which constitutes tho centre of 

 oscillation of tho beams that work the slides. The movement of the sieves is con- 

 trolled by that of the cam 11, 30, which works them all three by putting in motion a 

 shaft with which they are respectively keyed. The furnishing rollers receive their 

 movement from gearing with pinions on the axes of the rollers 8 8. The general 

 working of this complex machine remains to be described. When put into regular 

 motion, and the three blocks have delivered their impression exactly at the sama 

 instants three simultaneous movements then commence. 



1st. The stuff advances a distance exactly equal to tho breadth of the blocks, and 

 with it the blanket and backcloth, so that the portion of the fabric which leaves the 

 third block behind it, is fully printed ; that which was under the second advances 

 opposite the third ; that which was under the first, moves along to the second ; and a 

 fresh breadth of white or imprinted fabric arrives opposite the first. 2nd. While tho 

 cloth is advancing as above stated, the sieves take the place which they occupy in tha 

 section, fig. 329, that is to say, the first on the right hand rises, the second moves from 

 left to right, the third descends, and in this movement all three press slightly on tho 

 furnishing rollers 8, from which they receive the colour, which has been spread uni- 

 formly by the brushes 9. 3rd. In the meantime, the slides, or blockholders, by a for- 

 ward movement, push the blocks against the sieves, to charge them with colour, and 

 the blocks at the same time receive from the slides a gentle backward movement, during 

 which the sieves deviate from their position ; the blocks then return upon them, and 

 are drawn back again after being applied to a new part of the colour surface. When 

 these simultaneous movements have taken place, the action of the machine proceeding 

 without intermission, the sieves move back from before the blocks, and these are 

 pushed up against tho latter, printing the position of the fabric that is stretched upon 

 them. This brings the machine to that position at which the description commenced ; 

 and this succession of movements is renewed and repeated as long as the operation 

 lasts ; the printer having it always in his power to suspend the advance of the stuff 

 whilst the working of the blocks and sieves continues, so that the -colour may be 

 re-applied to the same part of the fabric as often as may be required for a good 

 impression. 



There have been several attempts at block-printing by machinery in this country, 

 amongst which the machines of Mr. Joseph Burch have been most successful ; but 

 from one cause or another, none of them have ever come into general use, and it is 

 unnecessary therefore to particularise them. 



The copper-plate printing of calico is almost exactly the 331 



same as that used for printing engravings on paper from 

 flat plates, and being nearly superseded by the next machine, 

 need not be described. 



The cylinder printing-machine is one by which one or 

 more colours are rapidly printed from engraved copper 

 cylinders or rollers by the mere rotation of the machine, 

 driven by the agency of steam or water. The productive 

 powers of this printing automaton are very great, amount- 

 ing for some styles to a piece of 30 yards per minute, 

 or a mile of printed cloth per hour. Fig. 331 will give the 

 reader a general idea of this elegant and expeditious plan 

 of printing. The pattern is engraved upon the surface of a 

 hollow cylinder of copper, and tho cylinder is forced by 

 pressure upon a strong iron mandrel, which serves as its 

 turning shaft. To facilitate the transfer of the impression 

 from the engraving to the cotton cloth, the latter is lapped 

 round another largo cylinder, rendered elastic by rolls of woollen cloth, and the en- 

 graved cylinder presses the calico against this elastic cushion, and thereby prints it as it 



