Several attempts have been made to apply other substances than plaster of Paris and type-metal for stereotyping. At the Great Exhibition there were specimens of gutta percha stereotypes, that produced excellent impressions, and there were also fine stereotype castings of type in iron, from which a copy of the Bible had been printed. Papier maché has been found to be a material peculiarly applicable for the purpose, and it is now superseding the use of plaster of Paris for taking casts of the types. By the application of the art of stereotyping, casts in metal of valuable works can be kept ready at any time, to be printed from when more copies are required; and the expense is saved of keeping on hand large stocks of printed paper, or of having a work recomposed when a further edition is wanted. The inventions of Printing Machines and stereotyping were strongly opposed at first by pressmen and compositors, as calculated to diminish the demand for their labour. In "Johnson's Typographia," published in 1824, the "new-fangled articles" are mentioned in a spirit of great bitterness; and the writer thus poured forth his lamentations at the prospective ruin of the members of his profession:--"We are much surprised at the apathy and supineness shown by the body of master printers with respect to the subject under discussion; they most assuredly had good and sufficient grounds for an application to Parliament for a tax, that should bring the work so executed upon an equality with that done by manual labour."--"We feel satisfied that the above would not have met with encouragement from a British public, had they been aware of the evils attendant on it; they have not only to pay a full price for the work, but also extra poor's rates, in consequence of the men being thus out of employ; likewise they are countenancing the breaking up and destruction of all the energy and talent of that art which was England's proudest boast, and her shield against all the threats of her foreign foes." These predictions of ruin have been completely falsified. It has been with the Printing Machines as with most other improved machinery for the saving of labour: on their first introduction some hands, no doubt, were thrown out of employ, but the advantages derived from the saving of labour very soon reacted favourably in creating a greater demand for labour than before. The number of cheap periodicals, and the extensive issues of cheap literature in every form, require a much larger number of workmen to supply the demand, even with the aid of machinery, than was needed in the best days of the manual printing press; and at no time were so many compositors and pressmen employed as at present.