Bronzing on Plated Papers.—Pressmen frequently find that they cannot print plated papers in bronze with success. The heavy coating on the paper absorbs the size so that the bronze will not adhere. This can be obviated by running the sheets twice through the press, using size both times, and allowing it to dry after the first impression, which it will very quickly do. The first printing fills up the pores in the paper, leaving an excellent ground for the second impression, to which the bronze will adhere firmly. Of course this is expensive; but it must be figured in estimating the cost of the work. —Printers' Album.

Safety Attachments to Guillotines.—Herr Karl Krause, the celebrated manufacturer, of Leipzig, has brought out a patent guard for guillotines, making accident with the knife almost impossible. As the cut begins, an ingenious mechanism shuts off the space in front of the knife by a wire guard, through which it is impossible to thrust hand or finger, while the cut is in no way hindered. Other safeguards are—a guard for the driving-wheels where they gear into each other; a fly-wheel guard; a guide-slot guard, covering the guiding-slots of the knife; and a safety-crank, obviating all danger from the fly-wheel when in motion.

The Two-Color Wrinkle.—Mr W. Timperley writes from Napier:—With regard to Mr Tombs's idea, which you illustrated in Typo for December, I will give you one more advanced, by which the necessity for transposing the pages is avoided. Impose the form thus: By this scheme, when the first color has been worked off, you have merely to turn your paper round, and clean up for another color. We used this method regularly and successfully at home for two-color posters.

Multi-Color Printing.—Paper and Press for August describes a method new in its application to typography, by which an inventor claims to have obtained sixty-two colors at one impression. It consists in chemical treatment of the inks, by which they may be worked in parallel lines without blending more than the width represented by four points, or a half-brevier. To the ink is first added a mixture (apothecaries' weight) of balsam of copaiba, ¾-lb; glycerine, ¼-lb; crude black petroleum, 30 drops; oil of sandalwood, 120 to 130 drops, according to the drying qualities of the glycerine. Stir enough of this mixture with the ink to bring it to a thick syrup. To this add a little of a mixture of one part chloroform and two parts ether— enough to stagnate the ink. The particles of ink will then appear to be working towards the centre, and this quality the inventor calls stagnation or deadening, the effect of the ether or chloroform being to keep the bands of ink in place, and prevent lateral spreading. Then add about the same quantity of the strongest liquor ammonia as of the chloroform solution. Bubbles will rapidly form in the ink, which is then ready for use.

Engraving-Machine for Rapid Work.—Paper and Press describes and illustrates a mechanical contrivance for producing matrix-plates for processes like the « Hoke. » To a swinging-plate, with universal movement, is attached two tools, a tracer and a cutter, so adjusted as to work perfectly parallel. The operator traces the picture or design, and simultaneously the cutting-tool engraves the matrix in fac-simile. It is asserted that the operation can be performed efficiently, easily, and correctly, even by an unskilled operator. Of this we have some doubt. We question whether a weighted tool, following the movements of a tracer, would cut as clean a line as one guided by a skilled hand. In any case, the necessity of keeping to the precise scale of the copy is a drawback. If the contrivance is really efficient, it should be attached to a pantograph, so that sketches might be enlarged or reduced to any desired proportion, simultaneously with the tracing operation. It is nearly sixteen years since Messrs Shanks & Johnston, of the Patent Type-foundry, London, invented a pantographic machine for similar work, the chief differences being that the line was not cut down to a foundation-plate, and that the depth of the cut could be regulated by a screw. It differed also in the nature of the cutting-tool, which was a revolving drill, maintaining a fixed position, the plate and not the tool being moved by the operation of the tracer. The machine was chiefly used for newspaper weather-charts. We have seen sketches produced by its agency, but they were not of a very high order of excellence.

Fluorography.—Under this title, the Revue de Chimie Industrielle et Agricole describes a process of transferring lithographic or phototypic prints to glass by means of fluorated inks, which, in contact with sulphuric acid disengage hydrofluoric acid, which eats into the glass. The phototype is inked with the following compound, in the given proportions (by weight): Soap, 50; glycerine, 200; tallow, 50; water, 100; borax, 25; fluorspar, 50; lampblack, 15. Negatives are taken and transferred to the glass. The latter is surrounded with a border of wax and covered with sulphuric acid of a density of 64° or 65° Baumé. After fifteen or twenty minutes the acid is poured off, and the glass is washed with water and cleaned with a solution of potassa, then washed with water again and dried with a cloth.

Improved Method of Etching.—According to the Papier Zeitung, of Berlin, a discovery has recently been made which bids fair to revolutionize the process of etching, especially in photo-gravure. The drawing is traced, as usual, on a plate of zinc, either by hand or by photography, with any suitable ground. The plate, backed with asphaltum, is laid in a bath of dilute acid. It is then put in circuit with a dynamo, the other pole being merely placed in the acid. When the current is allowed to pass, the acid attacks the metal with great rapidity, and a few minutes will suffice to bite the plate, and the depth of the etching can be easily controlled. The process is said to be far preferable to the old method in that the etching can be regulated with mathematical accuracy, while, after the old fashion, the surface becomes covered with a film of hydrogen or with a number of minute bubbles, which prevent an effect unless the plate be incessantly rocked or brushed. According to the inventor, whose name is withheld, the action of the acid in electric etching is due to a depolarization of the metal surface.

Multi-Color Printing.—We noted some months ago that a New York paper had succeeded in printing at a single impression an advertisement in color in the centre of a black form. Several methods of producing this result have now been brought into practical operation; but the necessary mechanism is much too intricate and costly ever to come into general use. The principle in all these inventions is much the same. The bed of the press is specially constructed in movable sections, and a stereotype form is prepared in sections to correspond. The portions of the form required to be of any given color are caused to rise automatically to a sufficient height to be inked independently of the rest of the form, and this operation is repeated for each color, the whole form being brought to a common level before receiving the impression. While the ingenuity of the process deserves admiration, its many disadvantages, apart from its great cost, must be evident to any printer, A simpler variation of the plan —obviously unsuited for fine work—is to have the colored portions permanently depressed, inked by a pad attached to a cylinder, and the impression effected by means of a sufficiently thick overlay.