THE PRINTING PRESS. 



found that they cannot be delivered with the necessary precision 

 by manipulation at a more rapid rate than two in five seconds, or 

 twenty-five per minute, being at the rate of 1500 sheets per hour. 

 Now, in this manner, to print at the rate of 10000 per hour, 

 would require seven cylinders, to place which so as to be acted 

 upon by a type- form moving alternately in a horizontal frame, 

 in the manner already described, would present insurmountable 

 difficulties. 



In the face of these difficulties, Mr. Applegath, to whom the 

 world is indebted for the invention of The Times printing- 

 machine, decided on abandoning the reciprocating motion of the 

 type-form, arranging the apparatus so as to render the motion 

 continuous. This necessarily involved circular motion, and 

 accordingly he resolved upon attaching the columns of type to 

 the sides of a large drum or cylinder, placed with its axis ver- 

 tical, instead of the horizontal frame which had been hitherto 

 used. A large central drum is erected, capable of being turned 

 round its axis. Upon the sides of this drum are placed verti- 

 cally the columns of type. These columns, strictly speaking, 

 form the sides of a polygon, the centre of which coincides with 

 the axis of the drum, but the breadth of the columns is so small 

 compared with the diameter of the drum, that their surfaces 

 depart very little from the regular cylindrical form. On another 

 part of this drum is fixed the inking-table. The circumference 

 of this drum in The Times printing-machine measures 200 inches, 

 and it is consequently 64 inches in diameter. 



The general form and arrangement of the machine are repre- 

 sented in fig. 10, where D is the great central drum which carries 

 the type and inking tables. 



This drum in The Times machine is surrounded by eight 

 cylinders, n, E, &c., also placed with their axes vertical, upon 

 which the paper is carried by tapes in the usual manner. Each 

 of these cylinders is connected with the drum by toothed-wheels, 

 in such a manner that their surfaces respectively must neces- 

 sarily move at exactly the same velocity as the surface of the 

 drum. And if we imagine the drum, thus in contact with these 

 eight cylinders, to be put in motion, and to make a complete 

 revolution, the type-form will be pressed successively against 

 each of the eight cylinders, and if the type were previously 

 inked, and each of the eight cylinders supplied with paper, eight 

 sheets of paper would be printed in one revolution of the drum. 



It remains, therefore, to explain, first, how the type is eight 

 times inked in each revolution ; and, secondly, how each of 

 the eight cylinders is supplied with paper to receive their 

 impression. 

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