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Inventions, Processes, and Wrinkles.

The Photographic Eye.—In a lawsuit in Germany, Dr J. M. Eider was called upon to see if he could determine the writing upon a document which had become illegible from ink spilt over it. By using an erythrosine plate, properly exposed by gaslight, and developed with pyro and soda, he was able to show the hidden characters beneath the blot that covered them.—Popular Science Review.

Autographs in Iron.—An invention by which writing can be transferred from paper to iron is the work of a Boston man, who has invented a hard ink with which to write (backward) upon ordinary paper. The paper is placed in a mould, melted iron is poured in, and when the hardened iron is removed it is found that, while the heat burned away the paper, it did not affect the ink, but left the impression of the writing moulded into the iron. This discovery was made by noting one day that the printing on an ordinary handbill, that by accident had fallen into the mould, was faintly transferred in this way.—Geyer's Stationer.

Artificial Litho Stone.—Messrs Capitaine & von Hertling, Berlin, have patented a process of manufacturing artificial litho-stone from chips and waste and broken pieces of genuine litho, and assert that their product is not only as good as the natural stone, but in some respects superior, in as much as it is less sensitive to atmospheric changes. Gun-cotton is dissolved in a mixture of ether and alcohol, or in camphorated spirit. Waste pieces of litho-stone are reduced to a very fine powder, which is mixed with the gun-cotton solution to the consistency of pulp, and is then pressed into moulds of any shape or size desired.

Inimitable Patterns.—The Paper Mill describes a peculiar process for producing patterns that defy imitation. Ink is applied to a lithographic plate of stone or other material, and another plate, which may also be lithographic, is placed face-to-face with the first; the two faces are rubbed together for a time, and then taken apart. By this rubbing action the ink is so distributed as to impart a variegated design to the plate. If the design so produced is not of a satisfactory character, the plates are again placed in contact, and rubbed until the desired effect is produced. The ink is then allowed to become dry, and the design printed from the litho plate in any manner desired. The varieties of design so produced are endless in configuration and shade, and their reproduction, except from the original plate, is said to be practically impossible.

To Re-surface Litho Stones without Grinding.—Herr E. O. Schmiel, Gohlis-Leipzig, has patented a process to prepare litho-stones, especially such as are soft or have chalk-spots, so that they may be used again without grinding with sand. The stone is first cleaned of all dirt and ink by washing it with benzine; then it is washed off with dilute sulphuric or hydrochloric acid, which removes any design there may be on the stone, but does not render it susceptible to a new transfer. To avoid the tedious process of grinding it off, pour upon the stone a strong solution of chlorate of magnesium to which has been added from five to ten per cent, of silicate of potassium; the mixture having been allowed to stand twenty-four hours without using. Leave it upon the stone for from five to twenty minutes; then, while the solution is standing upon the stone rub it off with pumice-stone; then place some carbonate of magnesia thereon. The latter, in consequence of previous treatment with chlorate of magnesium, will enter into a chemical combination with the stone, which is then ready for use. Writers in the New York Lithographic Art Journal state that the process is not a new one.

The Winder Automatic Compositor.—The Printers' Register says: In the « Winder » Automatic Composer and Distributor, the Trade has placed at its service another apparatus for composing and distributing type. The Composer is not a machine, but is an arrangement of tin tubes filled with types, which come from the Distributor, so that the person composing can with both hands extract the letters and place them in line in the stick. The stick is the same as the stick in ordinary use, with an added piece, and the lines are carried forward in the usual way. As the price of the Composer is only £9 10s., it can be readily imagined that it is exceedingly simple. The inventor claims that the attendant can easily set 3,000 ens per hour. Any size of letter can be set in each machine. The Distributor is a small machine, that can be placed on an ordinary table, and on being started with the aid of small power, does its work automatically. The types to be distributed are placed in column in a box and the machine extracts them line-by-line, and afterwards distributes them letter-by-letter into their proper receptacles. The types are slightly nicked. The machine is said to distribute 8,750 to 9,000 per hour, and we are informed that the result is absolute accuracy. The Distributors, each of which is about eighteen inches square, will distribute any font of type.

Imitating Type-Writer Work.—The typographic imitations of type-writer work, when carefully printed, look too clean to deceive the practised eye. We have already mentioned that an ingenious American had contrived a method by which the printing could be done with exactly the same defects as those of the instrument itself, and we indicated a means by which this not very desirable end could be accomplished. The actual method is the same in principle, but differs in detail. A sheet of silk is placed over the face of the type, screwed between the lines under the leads, and clamped at the ends to the chase. This produces the desired softened and blotted appearance of the letters, and the ink taken by the silk between the lines only dirties the paper sufficiently to make it look natural.

Printing Maps in Colors.—A map in black may be printed in colors in the following way: Make from the original lithographic stone as many transfers as you desire colors, and transfer them to lithographic stones which are prepared with asphaltum. Those lines which you wish to print from one stone in one color, you dust in with bronze powder, after which you expose the stone to the sun. The result will be that the exposed parts of the stone become insoluble, while the other parts, protected by the bronze-powder, remain soluble. Wash out with turpentine, so that all lines and reading-matter appear light in the brown asphaltum layer. The places which are not to appear in their respective color may be covered by means of a brush with an asphaltum solution, and then the stone may be etched as usual. In this manner the system of lakes, rivers, and creeks may be produced in blue, the mountains in brown, and streets and railroad lines in red. After etching the stone it should be oiled and washed out with ether, rubbed in with the respective color, and printed as usual.