PRINTING. 



PRINTING. 



760 



thus enabled to be set to work for the production of the requisite 

 supply. 



Another considerable advantage is, that the moulds may be pre- 

 served, so as to be used whenever wanted. It is only necessary that 

 they should be stored so as to be neither too warm, nor too damp, nor 

 too dry, as the paste will ferment, or the sheets crack and separate. 

 With care however they may be kept safe for a considerable time, and 

 thus the locking up of a large amount of metal may be avoided. 



The alloys used for various kinds of stereotyping differ slightly in 

 their composition, but generally consist of type metal. 



Stereotype-plates need careful examination and picking, to remove 

 the imperfections in the casting. Small hollows, such as the loops of 

 an a, an e, or an o, are liable to be filled up with metal, owing to blebs 

 of air in the mould, and the fine white lines in wood-engravings are 

 sometimes filled up. Such matters should be corrected by the picker, 

 who should also cut down, with suitable tools, such blank spaces as 

 might be liable to soil in printing. Before printing, also, defective 

 letters or words which cannot be corrected by the picker should be cut 

 away, and types inserted in their place. These types are soldered into 

 holes drilled through the plate ; their sterna being sawn off flush with 

 the back. 



Although the plates are cast of as equal a thickness as possible, they 

 require, before printing from, to be accurately flattened at the back by 

 means of a peculiar kind of lathe, in which a steel cutter, or knife, 

 mounted in a slide-rest, shaves off the metal from the back of the 

 plate in concentric circles, until it is made perfectly even. They are 

 then mounted upon blocks of wood or metal, to raise them to the 

 same height as common types. The tendency of wood to warp when 

 exposed to changes of temperature, or to occasional wetting, has led to 

 many projects for mounting stereotype-plates upon blocks of cement, 

 or upon metallic mounts which might be applicable to plates of various 

 sizes. When wooden blocks are used, the plates are usually secured 

 to them by clips at the edges, and sometimes by screws. 



The process of stereotyping is one of the most important means by 

 which the production of cheap books has been facilitated of late years. 

 For a work of limited and temporary demand it is unnecessary ; but 

 where the demand is very great, and likely to last for several years, it 

 is all-important, since it enables the publisher to keep up the supply 

 without the expense of having a very large edition printed at once. 

 In most cases where the demand is uncertain, and in almost all where 

 the demand is sure to be large, it is desirable to resort to stereotyping, 

 because, although it increases the first cost of production, it enables 

 the publisher to avoid, on the one hand, the risk of printing a great 

 number of copies which may prove unsaleable, and, on the other, the 

 outlay necessary for the re-composition of the types, in case the 

 demand should exceed the number of copies first printed. 



It has often been urged as an objection to stereotype printing that 

 it tends to perpetuate errors ; but the fallacy of such a statement may 

 be easily shown. In re-composition new typographical errors are 

 pretty sure to arise, while the expurgation of old ones is by no means 

 certain; but in stereotype plates the occurrence of new errors 

 (excepting by the breaking off of a letter or figure) is impossible, and 

 original errors may be altered whenever they are discovered. Such 

 alterations are not necessarily confined to the insertion of a letter or 

 a word ; for whole sentences and paragraphs may be altered in like 

 way, provided that the new matter be made the same in extent as that 

 which is cut away. Hence a stereotyped work may be gradually 

 rendered almost immaculate ; and an error which would otherwise 

 have run through the whole edition, may be corrected when only a 

 few hundred copies have been circulated. 



The interest connected with the question of Printing for the Blind, 

 t ; which considerable impetus was given by the Society of Arts for 

 Scotland at Edinburgh, who offered their gold medal for the best 

 alphabet for the blind, has tended greatly to bring about a change in 

 the intellectual education of the blind. The publication of the article 

 BLI.VD in the ' Penny Cyclopxdia' at a time when the minds of many 

 were thus directed, and the strictures therein contained on the absence 

 of intellectual training in most of the asylums, also rendered essential 

 benefits on this point. Dr. S. O. Howe, of Boston in the United States, 

 in 1833 contrived an alphabet, founded upon that of Hau'y, of a very 

 compact form, in which the New Testament was printed in 1834, and 

 is now in general use in America. The late Mr. John Alston, the 

 treasurer of the Glasgow Asylum, than whom no man connected with 

 the blind deserves more honourable mention, contributed greatly to 

 this educational movement. He saw that, by adopting any character 

 more or less arbitrary, the evil would necessarily follow of isolating 

 the blind by putting them in a position to require special teachers. 

 He therefore adopted the plain Roman characters deprived of then- 

 small extremities the iant-terif of type-founders ; and, finding that it 

 could be easily read, that it would enable any seeing person who could 

 read to be a teacher of the blind, he at once procured founts of type, 

 and published several works in raised letters ; the success of these for 

 their special object established the pre-eminence of his alphabet. Having 

 thus laboured for several years, he visited more than once the principal 

 Mylums for the blind in the kingdom. In his work ' Statements,' Ac., 

 published in 1846, he says, that after the introduction of his system, 

 <md a considerable improvement. St""oucntly I visited the 

 English institutions a third time, and found a very great number who 



could read with ease and intelligence ; and I have reason to know that 

 there are some hundreds reading these books, and that many families 

 are in possession of the whole of the Bible in raised types : thus in a 

 short time showing the sufficiency of the system placed before the 

 public." It may be added, that Mr. Alston also brought out some 

 beautiful music and maps, and that he published the Old and New 

 Testament in 19 vols., super-royal 4to. The paper used for these 

 works is strongly sized, to retain the impression. In order to account 

 for the great extent of the Bible, it must be borne in mind that the 

 paper can only be printed on one side, and that the letters require to 

 be of considerable size in order to be distinct to the touch. The print- 

 ing is effected by a copper-plate press. The types being strongly 

 relieved, and liable frequently to give way under the heavy pressure 

 required, it was necessary to have them re-cast four times during the 

 progress of the work. The whole of the works were completed within 

 the walls of the Glasgow Asylum, a man and a boy acting as composi- 

 tors, there being one pressman, and the ordinary teacher acting as 

 corrector of the press. These books are now used in most of the 

 British asylums for the blind, and also in America. The success which 

 has attended Mr. Alston's exertions was a new assurance to the Society 

 of Arts for Scotland that they had acted wisely in regarding the steno- 

 graphic and all other arbitrary characters, as well as the angular 

 modifications of the Roman alphabets, unfavourably. 



Mature-printing, also called A utotypography, is an invention introduced 

 from the Imperial printing-office in Vienna, by the late Mr. Henry 

 Bradbury. The merit of the discovery has been a matter of contest 

 into which we shall not enter, but we may remark that M. WORKING (in 

 BIOG. Div.), to whom we have attributed much of it, has disclaimed all 

 beyond carrying into effect the suggestions of Councillor Auer, the 

 director of the Imperial printing-office. The invention successfully 

 pretends to give an exact reproduction of natural objects, such as 

 plants, the grain of wood, &c. ; and of other flat substances, such as 

 lace, &e., in a form which enables a large number of impressions to be 

 printed, and in their natural colours. The transference of the forms of 

 plants to paper had been effected even centuries since, either by staining 

 the plants, or by simple pressure. In this manner, however, the object, 

 after taking a few impressions, was rendered useless. At Vienna the art 

 was rendered more perfect by taking an impression on polished lead, from 

 which impressions could be printed, though still in only a very limited 

 number. Softened copper-plates were then adopted, which were found 

 equally capable of receiving the impression, to its minutest markings, 

 of the substance pressed on it. The object is arranged on the plate in 

 the desired form, and is then subjected to an enormous pressure for a 

 sufficient time, when it is found that the object has left its form deeply 

 impressed upon the plate. This plate is subsequently hardened, and 

 is fitted to furnish a large number of impressions. The plates are 

 coloured, or inked as it is termed, with the proper colours of the plant, 

 which is easily done, as the face of the plate is wiped after each 

 colour has been kid on ; the paper is laid upon the plate and passed 

 through a press formed of two cylinders pressing against each other, 

 of which one is covered with thick blanketing, and with a regulated 

 pressure, the impression is produced in a low relief. In Vienna, 

 several works of a magnificent character have been produced. In Eng- 

 land there have been three, 'The Ferns of Great Britain;' 'British 

 Sea Weeds ; ' and ' Trees of Great Britain ; ' all of which possess a 

 high degree of excellence as works of art, and are of course of unexcep- 

 tionable correctness. 



Electro-printiwj. The processes of the " Electro Printing -Block 

 Company " (patented by Mr. H. G. Collins) supply the means of repro- 

 ducing drawings, engravings, &c., without the aid of copyist or engraver, 

 not only of the same size as the original, but enlarged or reduced with 

 strict accuracy to any extent that may be desired. Thus, from a wood- 

 cut or steel engraving, say of 6 inches by 4, a working plate or block 

 can be produced that will yield impressions 12 inches by 8, or 3 in. IKS 

 by 2, or of any other required proportion. We will briefly describe the 

 beautifully simple means by which this is effected, and then indicate 

 a few of its actual or probable applications. 



The whole, in fact, depends on the capacity of india-rubber for 

 extension in any direction, and its property of returning to its original 

 size when the tension is removed. Let us suppose that it is desired to 

 obtain an enlarged copy of an engraving. The surface of a sheet of 

 galvanised india-rubber, the size of the print, is covered with a film of 

 an elastic composition, and upon this film, when dry, an impression of 

 the print is taken by means of transfer ink. The sheet so printed upon 

 is then placed in a rectangular steel frame, hooks from the sides of the 

 frame passing through holes pierced at equal intervals in the edges of 

 the india-rubber. By a simple but ingenious double screw action, two 

 opposite sides of the frame are now gradually drawn apart, till it is 

 seen, by a scale engraved on the sides, that the india-rubber sheet is 

 sufficiently extended. The same is done with the other two sides ; and 

 the whole having been carefully examined to see that the enlargement 

 is uniform, the frame is fixed, in order that the strained sheet may not 

 be in any way disturbed during the next operation. The impression 

 thus enlarged on the india-rubber is now transferred by the ordinary 

 lithographic transfer process to a lithographic stone, or zinc plate, which, 

 after the usual treatment [LITHOGRAPHY], yields impressions exactly 

 like any other prepared lithographic stone. 



For a reduced copy, the only difference in the process is, that an 



