412 



PRINTING 



first forme, ami at the -<.. n.l cvlimlcr it n-,-.-i\.'.l 

 its impression from the second forme, Cowpcr 

 also improved on this machine, which printed >50 

 -he.-t- on both sides of the paper |x-r hour. The 

 principle of the first perfecting nmrliine has not 

 l'fii considerably departed from in sulxtequent 

 machines of the same clans, but improved methods 

 have been devi-ed for cai r\ injj the sheet from one 

 cyliinlor to the oilier ami turning it. 



Reference, extremely brief and im|>erfect, has 

 now been made to the origin of two out of the 

 three distinct clauses of printing machines at pres- 

 ent in use. These are, first, the single-cylinder 

 machine, printing one side of the sheet at one 

 operation, from a forme lying on a Hat bed ; second, 

 the double-cylinder or perfecting machine, printing 

 lioth sides of the sheet at once, also from a forme 

 on a flat l>ed. The third cla-s comprises the rotary 

 machines, printing both sides, hut from a circular 

 forme the impressing surface, as well as the 

 printing and the inking surface, Itting cylindrical, 

 and capable of continuous rotation. The machines 

 of the first and second classes are adapted for 

 single sheets of paper ; the rotary machines print 

 reels or continuous wel>s, the jtortion forming a 

 sheet being severed after printing. It is in this 

 latter class of machines that the greatest improve- 



ments amounting almost to a revolution in the 

 art of minting have been achieved. I l-'or a 

 technical account of the .-event! classes, Bee J'riti- 

 ciptes and Progrett tff PraUiiy M<t< liinn-i/, by the 

 present writer, Load. ISS'.I.) Limitations of space 

 preclude more being given here than a bare list of 

 successive impro\cmeiits. 



In 1790, as already mentioned, Nicholson patented 

 a rotary machine, but he never constructed one. 

 In 1813 Itacon and Donkin patented a machine 

 in which the types were fixed on a revolving 

 prism, the ink liemg applied by a roller, and the 

 sheet of pajier wrapped on another prism. The 

 machine was a failure, although it embraced 

 nn important feature, the inkiiig-roller made of 

 composition. Three years afterwards Cowper 

 patented a method for printing paper for paiier- 

 baojringg and other purposes. f i i,i s embodied 

 another valuable feature the taking a cast from 

 the type and lieniliiig the cast round a cylinder. 

 It was a far more practical idea than the subse- 

 quent one of Rowland Hill, who, to procure a 

 curved printing surface, proposed the use of toper 

 ing types to lie fixed on the cylinder. In 1848 

 Applegatli invented a machine, the type-cylinder 

 of which was vertical and nearly 6 feet in dia- 

 meter, around it being placed eight other cylinders, 



Fig. 6. The Walter Presa. 



containing sheet* of paper to be printed. The-e 

 were ted in from a horizontal position, and then 

 brought to the vertical position. In 1857 the 

 Time* discarded this machine in favour of one 

 patented by Hoe of New York, very similar in 

 construction, but the cylinders were horizontal. 

 It was found that the complication arising from 

 eight or ten feeders was most objectionable, 

 causing frequent stoppages, excessive wa-te of 

 paper, and great risk to the machine and the 

 material, while the working cost \\a~- heavy. 1/n-li 

 of the machines printed on one side only. They 

 were the first machines fitted with ' flyers ' a 

 device for mechanically delivering or taking off the 

 sheets. It was, however, considered at the Timi'n 

 ollice. that the acme of improvement could only be 

 obtained by constructing a machine simple in its 

 arrangements, capable of printing both sides of the 



paper at one operation, and which could print, not 

 single sheets, but continuous webs of paper, thus 

 dispensing with liiyers-on. Then 1 wen- enormous 

 dilliculties in the way of printing, rutting, and 

 delivering the paper, dilliculties which the non- 



Iuofessional reader could by no means realise, 

 n 1806 a machine of the kind was constructed 

 under the superintendence of Mr J. C. Macdonald, 

 the manager, and Mr Calverley, chief-engineer of 

 the Times. The Walter Press, as this machine 

 was named, has since been slightly improved, 

 hut remains practically the same, and is shown 

 in fig. 0. The types are stereotyped by means of 

 a papier-mache, mould, which, l>cing lient inside a 

 hollow cylinder, produces, when cast, a stereotype 

 which fits on the printing-cylinder of the machine. 

 The paper, unwinding from the reel, first pas-e- 

 between damping-cylinders, then over the printing 



