THE PRINTING PRESS. 



The ductor-rollers, c and c', are kept in revolution by endless 

 bands, carried over rollers at the lower parts of the frame, and 

 then over grooved wheels fixed on the axes of the cylinders. The 

 table carrying the forms and slabs is moved alternately right and 

 left by means of a pair of bevelled wheels, w, under the frame, 

 and a double rack and pinion above ; one of the bevelled wheels, 

 having a horizontal axis, receives motion from a steam-engine 

 or other moving power ; it imparts motion to the other bevelled 

 wheel, having a vertical axis. This latter axis has a pinion fixed 

 at its upper end, which works in a double rack attached to the 

 movable type-table, which is so constructed that the continuous 

 rotation of the pinion imparts an alternate rectilinear motion 

 right and left to the rack and to the table attached to it. 



The manner in which the tapes lay hold of and conduct the 

 paper successively round the cylinders, and finally discharge it 

 upon the table of the taker-off, will be easily understood by re- 

 ference to fig. 8, page 177. 



c and D are two grooved rollers, surrounded by an endless band 

 which pushes the paper from the table of the layer on towards the 

 tapes. The two endless tapes, between which the paper is held, 

 are represented in the diagram by the continuous and dotted 

 lines, and the direction of their motion round the rollers and 

 cylinders is represented by the arrows. It will be perceived that 

 opposite the table of the layer-on, the tapes converge, from two 

 small rollers d and A, and come into contact at the top of the 

 roller E. The edges of the sheets of paper, being advanced from 

 the table of the layer-on, are caught between the tapes im- 

 mediately above the roller E. 



It must be understood that there are two or three pairs of tapes 

 parallel to each other, which correspond to the margins of the 

 pages or columns ; but only one pair is shown in the figure. 



The paper being thus seized between the tapes above the roller 

 E, is carried successively, as shown in the figure, still held 

 between the tapes, under and over F H I and G, until it arrives at 

 i, where the tapes separate, that which is indicated by the con- 

 tinuous line being carried to the roller a, and that by the dotted 

 line, over the roller *, to the roller k. The tapes being thus se- 

 parated the printed sheet is discharged at , upon the table of the 

 taker-off ; meanwhile, the tape indicated by the continuous line 

 is carried successively over the roller a, under b, under c, outside 

 d, and is finally returned to the roller E. 



In the same manner the tape indicated by the dotted line is 

 carried successively under the roller k and m, outside n, over v 

 and A, from which it returns to E, where it again joins the other 

 tape proceeding from d. 

 16 



