STEREOTYPE PRINTING,
which is a modern improvement, is a mode of rendering a work permanent in Type, in the following manner. When the Type has been accurately corrected, the Pages of Type are properly arranged for the purpose, when a cast is taken of them in a Plaster Cement, which becomes hard when dry: into this mould melted Type Metal is poured, and thus a perfect counterpart of the Type is produced of each Page, in one solid Plate. This mode was brought into notice by the late Lord Stanhope. The first attempt to render a work thus permanent, and which appears to have been adopted solely with the view of preventing error, was made by a Printer at Leyden, about a hundred years since. He produced a Quarto Bible, Printed from solid Pages, but these were rendered solid by soldering together the backs of the Types. The present mode is, of course, a great improvement on this; as instead of incurring the heavy expense of so large a quantity of moveable Type, the same result is produced, and the Type from which the cast is taken remains uninjured, to be used again and again, for the same, or any other purpose.
Stereotype Printing is thus a very valuable process, for works not liable to alteration, as Bibles, School Books, and other works of which large numbers are required, as it would be impossible to keep the moveable Types standing for such works, without a very great outlay of Capital.[22-*]
Another mode of Printing, is that called
LITHOGRAPHIC PRINTING,
or Printing from Stone. This is also a recent invention. It was brought into England about twenty years since. Invented by M. Senefelder, of Munich. It is founded on the principles of Chemical Affinity. A Writing or Drawing is made on Stone, with an Ink prepared with a sort of unctuous ingredient—to this is applied another Ink of a contrary quality; the Ink with which the Writing or Drawing is made, remains on the Stone, while that with which the Printing is performed, separates from it, and is thus transferred to the Paper. This method has been brought to very great perfection; so much so, as to produce Prints from Drawings possessing nearly all the beauty and delicacy of Copperplate or Steel Engravings. It is also very useful in multiplying Fac-similes, as it admits of Printing from the hand-writing itself, when written with Ink prepared for the purpose. At Munich, Paris, and St. Petersburgh, this mode of Printing has been adopted in the Government Offices. All Resolutions, Edicts, Orders, &c., agreed to at the Cabinet meetings, are written down on paper, by the Secretary, with Chemical Ink, and in the space of an hour, an ample supply of copies is obtained. For Circulars, and in general, all such orders of Government as must be rapidly distributed, an invention like this is of the utmost consequence, and it is probable that eventually it will be universally employed. In time of war it would prove of the greatest use for the general staff of the Army, completely supplying the want of a field Printing-Office, and especially as it admits of greater despatch and secresy. The Commanding Officer might write his orders with his own hand, and in his presence a number of impressions might be taken by a person who could neither write nor read. In mercantile transactions, it is very generally employed where a quick and accurate multiplication of Price Lists, Letters, and Accounts, is of the utmost importance.
COPPER-PLATE PRINTING.
Copper, or Steel-plate Engravings, are Printed by a different process. The Copper, or Steel-plate Press, is formed of two Rollers, one placed over the other, with only a sufficient space between to allow a board to pass, when a strong force is applied. The Plate is then laid on a small fire adapted to the purpose, so as to heat it sufficiently to liquify the Ink, and cause it to diffuse itself over every part of the Engraving. It is then made perfectly clean, so as to leave no soil on the paper, except from the parts indented. It is then laid on the board, the Paper spread upon it, and a soft cloth being added, the Roller is turned by a Cross Lever, when the Print, with all its varied tints, is immediately produced.
ENGRAVINGS ON WOOD.
Engravings on Wood, are usually Printed with the Letter Press, for which they are peculiarly adapted.