Inventions, Processes, and Wrinkles.

Cold Stereotyping.—Mr J. A. St. John, the inventive manager of the Centra] and Boston Typefoundries, says the Inland Printer, has hit upon a valuable idea in drying stereotype matrices by cold instead of heat. The theory is correct.

The Latest Automatic Relief Process.—According to the Denver Sun, Mr John G. Garrison, an experienced printer, and one of the proprietors of the South Denver Eye, after seven years of experiment, has perfected and patented a machine which is expected to revolutionize engraving and stereotyping in many of its branches. His process is simple. A very thin sheet of copper is fastened upon a soft surface, and the drawing is made upon the copper with a style, adjusted in such a manner that it makes a perfectly uniform impression in the copper, not cutting it, but pressing it into the soft bedding so that the figure or writing appears raised on the reverse surface. The copper plate is then placed in a stereotyper's casting-box, and the indented surface becomes a matrix for the casting of stereotypes. If an electrotype is desired, the copper is first coated with acid so that it combines with the melted type-metal, and the raised surface of the copper becomes the face of the plate. Among the advantages claimed for the invention are these—that any man who can draw may, with this machine and a casting-box, make his own engravings ready for the printer, almost as quickly as he could make an ordinary drawing. Autograph letters may be reproduced almost as rapidly as one can write. It is expected that the machines will be put on the market at $100, and that every printer will thus be able to make his own engravings at a trifling cost. A similar process was attempted and patented ninety-three years ago, but was not a success, and never came into use. Mr Garrison has succeeded in overcoming the obstacles that were fatal to the other invention.—We are a little sceptical as to the capabilities of this ingenious scheme, especially as the description does not appear to be the work of a practical man. No accurate writer would style a mechanically-indented copper plate an « electrotype. » The process, if practicable, seems only suitable for the very roughest work, and the stereo, with or without the copper face, will require considerable routing. It is manifest that a cast from the indented side of the plate would give a lighter and quite different impression from that of the plate itself. ؟How are the varying thicknesses of lines, on which ail the character of an outline sketch depends, obtained with a style mechanically operated? Uniformity of line is an excellent quality in a geometrical diagram, but is intolerable in a graphic design. The process would give a bad line, of the rounded form ∩ which is the printer's abhorrence, instead of the Λ or ∏ shape. For certain classes of work the invention as described may prove both useful and economical, but we do not look for any « revolution » when the machine is placed upon the market.