THE PRINTING PRESS. 



them* As the inking-table attached to the revolving drum 

 passes each of these ductor-rollers, it receives from them a coating 

 of ink.. It next encounters the inking rollers, to which it 

 delivers over this coating. The types next, by the continued 

 revolution of the drum, encounter these inking rollers, and 

 receive from them a coating of ink, after which they meet the 

 paper-cylinders, upon which tli^- are impressed, and the printing 

 is completed. 



Thus in a single revolution of the great central drum the 

 inking-table receives a supply eight times successively from the 

 duetor-rollers, and delivers over that supply eight times succes- 

 sively to the inking rollers, which, in their turn, deliver it eight 

 times successively to the faces of the type, from which it is con- 

 veyed finally to the eight sheets of paper held upon the eight 

 cylinders by the tapes. 



Let us now explain how the eight cylinders are supplied with 

 paper; Over each of them is erected a sloping desk, A, A, &c., 

 upon which a stock of unprinted paper is deposited. Beside this 

 desk stands the layer-on, who pushes forward the" paper, sheet 

 by sheet, towards the tapes. 



These tapes, seizing upon it, first draw it down in a vertical 

 direction between tapes in the eight vertical frames, until its 

 edges correspond with the position of the form of type on the 

 printing-cylinder. Arrived at this position, its downward motion 

 is stopped by a- self-acting apparatus provided in the machine, 

 and it is then impelled by vertical rollers towards the printing 

 cylinder, these rollers having upon them marginal tapes which 

 carry the paper round the cylinder, from which it receives the 

 impression of the types. After this the central and lower marginal 

 tapes dismiss the sheet of paper, which the upper ones only become 

 charged with, and carry it to its proper place, where the tapes are 

 stopped with the paper suspended between them, until the taker- 

 off draws the sheets down, ranging them upon his table. These 

 movements are continually repeated ; the moment that one sheet 

 passes from the hands of the layer-on, he supplies another, and 

 in this manner he delivers to the machine at the average rate of 

 two- sheets every five seconds ; and the same delivery taking place 

 at each of the eight cylinders, there are sixteen sheets delivered 

 and printed every five seconds. 



It is found that by this machine in ordinary work between 

 10000 and 11000 per hour can be printed ; but with very expert 

 men to deliver the sheets, a still greater speed can be attained. 

 Indeed the velocity is limited, not by any conditions affecting 

 the machine,, but by the power of the men to deliver the sheets 

 toit. 

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