2. That the drying by the draft of air is regulated, and at the same time the air can be driven to a more rapid current.
3. That the grain formed by this extraordinary method is unusually perfect, and the nature of the grain more pleasing to the eye than when formed by chlorides.
4. That, as already stated, a rolling up or an uneven drying is hereby {100} positively prevented, as the paper is placed tight around the cylinder. And now for the main advantage:
This so dried paper is ready for use, and, when exposed to light, under a negative, produces a perfect and correct picture, which, when rolled up with transfer ink and developed in water, is ready for transferring direct on to the lithographic stone, or on to a metal plate, and to be further proceeded with as usual.—EDWARD MEISSNER.
TO PRODUCE GRAIN ON A NEGATIVE.
The negative is taken, and a solid pigment of Chinese ink sprinkled on it with the Air Brush, by which it gets a wonderfully fine grain. A coarser grain is made in a similar way, by sprinkling with a knife over a tooth-brush that has been dipped in Chinese ink. The Air Brush, however, will always be found the most suitable instrument, and now a wide field for its use is opened to artists of all classes. Instead of using Chinese ink, gamboge, or any other solid and well-covering pigment may be used.
For the practical photo-engraver, lithographer, photo-lithographer, and other men of experience in photo-mechanical processes, no further explanation is required. They will at once see the superiority of this process over everything that has hitherto appeared. After the information we have just given, they will all be enabled to do work by this process. It will henceforward be easy to produce photo-lithographs for lithographic printing as well as printing plates for the type press without difficulty, in a short time, and at trifling expense.—FRED. BUEHRING.
ON THE USE OF ACIDS.
A few hints on use of the acids will form my contribution to your work:
In order to obtain a proper resistance and firmness in the lines, it is necessary to prevent the acid from making the base that supports them too thin, and to strengthen the base by giving the depression the form of a V, and the base itself the form of an A. The depth must be great enough in the broad blanks to prevent the roller from sinking (although there is no danger of this when the lines are close together), and thus soiling them. A useless depth between very thin sides might weaken them; but, in the process employed, the attack by the acid continues only in proportion to the width of the spaces to be excavated. {101}