PRINTING AND MAKING OF BOOKS 



time of casting a plate for each machine. In some of 

 the newspaper offices of New York and London as 

 many as five of these machines were operated at the 

 same time. 



But still the capacity of these machines was limited 

 to the possible speed of the hand feeders. The paper 

 was fed in sheets cut to the proper size, and each one 

 must be handled either by a human feeder or by some 

 mechanical device. It was impossible to increase the 

 speed of the printing cylinder, therefore, beyond the 

 speed-capacity of the feeders. To overcome this defect 

 several inventors began experiments with machines that 

 would do away with feeders and single sheets of paper, 

 printing from continuous rolls or "webs" of paper, and 

 cutting off the paper into proper lengths after the im- 

 pression had been made. 



To those unfamiliar with the subject, this under- 

 taking would seem to be a comparatively simple one, 

 consisting essentially of some device for cutting off 

 the paper at definite intervals; but in practice many 

 difficulties were encountered. First of all there was dif- 

 ficulty with the inks, and ink-makers were urged to pro- 

 duce rapid-drying and "non-setting-off" inks; and 

 these were soon produced. Another difficulty was in 

 obtaining paper in the roll of uniform strength and 

 perfection; but paper manufacturers, by giving special 

 attention to the making of these rolls, soon produced a 

 satisfactory product. But, curiously enough, the prob- 

 lem of rapidly severing the paper was one of the 

 most perplexing to the inventors, and was not solved 

 until 1871, in a new Hoe machine. In this the sheets 



VOL. vni. 9 [ 1 29 ] 



