414 



riMNTINU 



of the cylinder ; the arrangement* for carrying the 

 forme of tv|>e up in and under tin- cylinder, hy 

 contact of which it receive* the impression ; the 

 inking of the type ; the laying on of the sheet ; the 

 taking o(T or delivery of the sheet w hen printed. 

 The cylinder, which ia a hollow .hum. having 

 an o|N-niiig on its under side, is placed almost in 

 tin- iniiiilleof the machine. The tahle of the machine 

 on hieh the forme is placed has racks on it- under 

 surface gearing into the traverse wheels, from which 

 it tleri\es motion to and fro. Hy means of racks 

 it also causes the rotation of the cylinder hy which 

 the impression of the forme is effected. The inking 

 sy-teni may he thus outlined. There U at the 

 extremity of the machine and running across it a 

 duct or ink reservoir, with an adjustalue side-piece 

 called the knife, which regulates the outflow of ink. 

 A composition roller in motion, called a vibrator, 

 takes a streak of ink periodically and transfers it 

 to the ink-table, which forms part of the tahle and 

 of course moves backward and forward. The ink 

 is evenly spread or distributed over the ink-table 

 by 'distributors.' The table then passes under the 

 inking roller- which alone touch the forme and 

 give it the proper coating of ink. The distributors 



and rollers are coated with 'composition,' referred 

 to on p. 410. The feeding apparatus is also ingeni- 

 oii-. A pile of pa|MT is lam on to the desk like 

 table .-how n at the right-hand side of the machine, 

 and a I HIV stands at the end or at the front side of 

 it and 'strokes' the sheets down till the front edge 

 of one comes in contact with a series of metal 

 lingers or clutches called grippers. These OJMMI 

 and take a sheet by its edge, and hold it serin e 

 while the cylinder is turning round, and the piint- 

 ing taking place. At a certain point the grii.jii-i- 

 releaxe the sheet, which then goes into the taking 

 off apparatus. A second set of grippers -ei/e it 

 and carry it round the wooden flyer cylinder, from 

 whence it emerges on to travelling tapes. A large 

 comb-like appliance called the gate oscillates up 

 and down, having the sheet in front. The pres.-me 

 of the air causes the sheet to adhere to this until 

 it assumes a horizontal position, when it .Imp- on 

 to the taking-ofT board. While the first side of the 

 sheet is being printed, two points, by an ingenious 

 arrangement, make small hides in the paper; and 

 when the sheet is turned to print the second side, 

 these holes are again placed on the 'points,' thus 

 ensuring correct register. 



Fig. 9. Perfecting Machine. 



Machines with two cylinders are called perfect- 

 ing machines because they perfect or print both 

 side* of a sheet before delivering it. Generally 

 they may be said to lie duplicated single machines, 

 with two printing-cylinders, two tames for type, 

 and an inking apparatus at either end, much as 

 described under the single-cylinder machine. The 

 sheet is printed on one side at the first cylinder, 

 when a set of gript>ers on the second cylinder take 

 possession of it ana print the second side, and it is 

 delivered by the liver as described. The varietieH of 

 these machines are numerous, and fig. !l shows the 

 Marinoni, a well-known type, used in the printing 

 of the British editions of the present work. These 

 machines can print in the very finest manner from 

 1000 to 1600 perfected sheet* per hour, according as 

 thev may be complicated with illustrations or not. 



\Vhen the types are to l>e printed from direct, ao 

 already mentioned, the chase containing the pages 

 is put on the bed of the machine. \\ hen stereo- 

 type or electrotype plates- are used they are care- 

 fully dieted to an exact size and thickness, the 

 latter about Aths of an inch. The requisite 

 number of wooden blocks are then put on the 

 machine-bed, locked in a chase. These blocks 

 are of the proper thickness to make up the plates 

 to type-height (about 1 inch). The plates are 



fastened to the blocks by brass catches at the sides 

 and ends, and when locked up are as solid as type. 



Before printing, however, a laborious process 

 called making ready has to be gnnc through. 

 When many wood-engravings are in the pages 

 -\eial days may be taken up making ready a 

 single sheet. This process is for the purpose of 

 making the impression equal all over and properly 

 printing the wood-engravings, and can lie judged 

 of by comparing a carefully printed book with n 

 daily newspaper, which is printed just as it comes 

 without any making ready. It is too technical 

 for detailed description within our limits. 



It is not long since that it was a firm article 

 of belief among printers that fine work could 

 not be done except on a press provided with a 

 platen. And up to quite recently all paper was 

 first thoroughly wetted, then printed, then dried, 

 and then pressed to restore the surface, of which 

 the damping deprived it, and to give it a certain 

 gloss. Between the forme and the platen of the 

 press or the cylinder of the machine a thick, 

 soft, yielding blanket was placed, which was sup- 

 posed to produce a better impression from the in- 

 equalities of engravings and type. There has lieen 

 a radical change in opinion and practice on these 

 important point-. It ha* been found, since machines 



