CHAMBERS'S INFORMATION FOR THE PEOPLE. 



bars. The moveable portion consists of two large 

 cylinders revolving on upright supports ; two 

 smaller cylinders or drums revolving above them ; 

 and beneath, within the framework, a movable 

 table, on which lie the types at both ends, going 

 constantly backward and forward. A boy, marked 



Fig. 6. 



a in the fig, standing on the top of some steps, 

 feeds in sheets of paper, each of which, on being 

 delivered, is swept round the first cylinder b 

 (being held on by tapes), gets its impression below 

 from the types, is carried over and betwixt the 

 drums above, and then brought round on the 

 second cylinder c; now it gets its second side 

 printed, and issuing into the space between the 

 cylinders, is seized by the boy d, who lays it on a 

 table completely printed. At each end there is an 

 apparatus of rollers taking ink from a ductor or 

 reservoir of that material, and placing it upon a 

 portion of the moving table ; here other rollers 

 distribute it, while others take it off and roll it 

 upon the pages of types, ready for each impres- 

 sion. The most skilfully contrived part of the 

 machine is the arrangement of the endless tapes, 

 which, taking the sheet from the hands of the 

 upper boy, retain it, in its progress over both the 

 cylinders, and finally deliver it to the boy beneath. 



The cylinders have a continuous rotatory motion 

 towards each other, given by two large toothed 

 wheels, whilst the table carrying the types moves 

 backwards and forwards under them. The move- 

 ments are so ccntrived that the types shall have 

 gone and returned to the same point during the 

 period that the cylinders have made one entire 

 revolution ; consequently, each successive impres- 

 sion is taken from the types by the same part of 

 each cylinder. The two drums placed between 

 the cylinders are for the purpose of causing the 

 sheet of paper to pass smoothly and accurately 

 from one printing cylinder to the other. 



But the printer has much more to do than simply 

 put the types in his machine and begin to print. 

 If the surface of the types were mathematically 

 level, that might suffice, but practically the sur- 

 face is very unequal. If a sheet were printed 

 without preparation, it would be found that some 

 places would be printed quite black, while others 

 were not printed at all. To remedy this the 

 machine-man prints a sheet, and then proceeds to 

 cut out the parts that are too heavy, and pastes 

 little pieces of paper over those that are too light. 

 This is put on the cylinder exactly over where the 

 types are pressed at each revolution, and the 

 whole covered with a blanket fixed on the cylinder. 



762 



Another sheet is printed, and the process repeated 

 until the nearest possible approach to perfection 

 is obtained. This 'making ready,' where good 

 work is required, takes a considerable time. As 

 an example, it may be mentioned that several 

 sheets of the present work, consisting of 16 pages, 

 and where many wood-engravings occur, have 

 occupied the whole time of the machine-man for 

 two or three days before a copy could be printed. 

 When fairly started, great care has also to be 

 taken that all the sheets are of uniform ' colour,' 

 a matter of extreme importance in the appearance 

 of the finished book. 



Many modified varieties of the cylinder machine 

 have been introduced ; the most important of them 

 is the Gripper. In this machine the types are laid 

 on a travelling table like that described above ; the 

 cylinder which gives the pressure is reduced to 12 

 or 1 8 inches in diameter, the drums are dispensed 

 with, and the tapes are replaced by a contrivance 

 called a gripper. This consists of a series of brass 

 grips like fingers arranged along, and fixed to the 

 cylinder ; they seize the sheet at the proper moment, 

 and retain it till it is delivered printed. The single 

 gripper is supplied with points for registering. 

 In the double or perfecting variety, the sheet is 

 delivered from the first cylinder into the grippers 

 of the second. There are many varieties of gripper 

 machines ; the most popular are the Wharfdale, a 

 single, and the Marinoni,a. double gripper. They 

 produce first-class work, and are well adapted for 

 nearly every description of printing. 



Besides those various descriptions of machines 

 above alluded to as being principally in use, there 

 are others calculated to execute work of a more 

 peculiar nature. Perhaps the most wonderful of 

 those ingenious pieces of mechanism is a machine 

 which has been made to print two colours by only 

 one impression a lower form charged with one 

 colour being caused to rise through and come 

 upon a level with another form, so that both may 

 be printed at once. Hitherto, the work which has 

 been executed by this machine has consisted 

 chiefly of the stamp-duty marks for the Excise, 

 and for bank-notes, fancy labels for druggists, and 

 other similar jobs. There may also be noted the 

 Conisbec two-colour printing-machine, printing 

 two colours by one cylinder, having two forms laid 

 on a traversing table, and ink-ducts at each end. 

 The first revolution of the cylinder takes the first 

 colour, and the second the other colour, and then 

 delivers the sheet. 



Extra-fast Machines. 



Non-registering machines for rapid printing are 

 of various kinds, according to the degree of speed 

 which is demanded. In those first introduced, the 

 principle was that of pressure by a cylinder on a 

 form of types laid upon a table, which was passed 

 beneath it by a forward and retrograde motion ; 

 the inking being effected as in the above-described 

 perfecting machines. Having received one side 

 by this means, the sheets were afterwards printed 

 on the second side ; such second impression con- 

 taining the news up till the latest hour of going to 

 press. This species of single cylinder printing- 

 machine was well adapted for newspapers of 

 which only a few thousand copies were wanted ; 

 and for this purpose, it is still in use, particularly 

 in provincial towns in Great Britain. As presses 

 of this sort, however, do not usually yield more 



