In R. M. Hansen's " writing ball," the chief peculiarity is that the keys are all arranged over s. semi-spherical surface, which, to a certain extent, conforms to the shape of the hands. The keys are formed of pistons, set s.s radii of the sphere, so that each key strikes at the same spot. The keys are depressed directly by the fingers, and are raised by small springs. The paper (carbonized and white) is carried either by a cylinder or a plate under the " ball." In the original machine, the paper was rnoved continuously by clockwork, or a small electrical motor ; but in the more recent forms, the paper is traversed by a movement derived from the key which is depressed. This slightly depresses the bed on which the ps.per is supported, and by suitable apparatus, this movement is caused to carry the paper forward a single space. It is stated that with practice, great rapidity can be attained by the machine, s.nd the direct action of the keys on the paper enables considerable force to be applied, and consequently s. large number of " rnanifolded" e,opies to be obtained.
The " Remington" machine hes in front a key-board holding the letters and numerals; on pressing any one of the keys, a small lever bearing the corresponding letter is made to strike against a ribbon saturated with prepared ink (presumably glycerine and BM aniline violet), over which, the paper is held on a roller. Each letter strikes s.t the same spot, but the roller and paper move one space forward after each letter, so that each letter falls into its proper place. The mechanism is very simple, the levers carrying the letters being actuated by BD arrangement similar to that of s. piano, and strung on a circular wire, so that they all strike into the centre of the circle. As soon as a line is finished, the roller is taken back to its original position by a treadle, and is at the same time revolved one tooth of a rachet-wheel, so as to bring a fresh line under operation. The type is all " small capitals," and the printing is regular and even. It is said to be easy to attain twice the speed of ordinary writing. The machine will " manifold" about 20 legible copies with earbon-paper.
In A. Barlow's machine, a vertical cylinder carries the types, and is raised or lowered to bring the required letter opposite the place on the paper where it is to be impressed. This raising or lowering is effected through the action of one key, which, being raised or lowered to a certain height, acts through suitable mechanism to raise OT lower the type-cylinder likewise. The key is slotted with a number of slots corresponding to the number of letters ; the finger being placed over the slot, and the key depressed, it descends until it reaches the level of a pin which enters the slot and is stopped by the finger. All the other pins pass freely through their slots.
The " Crandall " type-writer (Caldwell, New York), is a email machine costing 10/,, weighing 9 lb., mechanical and automatic in action, self-contained, and manipulated by 27 keys. lt writes
capitals, small letters, script, atunerals, and all the various stops and signs. The keys are grouped to facilitate the writing of oft-recurring small words. Each letter is written in front of the operator, and eau be seen as soon as written ; 60-70 words a minute can be written after short practice, and over 100 by experts. It ntanifolds readily. Circulars written by it go as "printed. matter " by post.
Autographic Processes—Manifold Writers.—Perhaps the most simple and effective methods of obts.ining a very limited number of copies of s. document by one operation of writing are the ordinary pencil s.nd carbon-paper, and the familiar copying-ink and tissue-paper. For obtaining a large number of copies, however, while too few for a lithographic press, several methods have been ree,ently introduced.
In Zuccato's " papyrograph," a sheet of fine paper is saturated with a resinous varnish, and dried. On it, writing is made with an ink consisting of a strong solution of caustic soda, slightly coloured in order to be more obvious to the eye. The soda immediately attacks the resinous preparation of the paper, converting it into s. soap. The sheet is floated on water, the written side being upwards ; the water soon penetrates the softened parts, making the written lines stand up in bold relief as ridges of fluid. The paper now removed from the surface of the water, and pressed between folds of blotting-paper, after which it is once more floated on the surface of the water, and again blotted off, in order to remove the remainder of the resin soap. The sheet thus prepared forms a stencil, of which the general ground is impervious to moisture, while the written lines, being denuded of varnish, are quite porous, and afford an easy passage to an aqueous liquid. In the early days of papyrogrs.ph printing, s. pad, saturated with persulphate of iron, was placed at the back of the stencil, while the paper to be printed on was moistened with a solution of ferrocyanide of potassium. The iron salt being forced through the porous lines by a gentle pressure, reacted on tbe ferrocyanide ; a blue impression was the result. It is now, however, found to be more convenient to print froru the stencil by means of BD aniline colour dissolved in glycerine, and the colouring power of this kind of ink is so great that dry paper may be used for receiving the impression. On a velvet pad which has been moistened with a solution of aniline blue in glycerine, is laid the paper stencil, this bating been previously brushed over at the back with a little of the ink. It is now merely necessary to place sheets of paper on the upper face of the stencil, and to apply gentle pressure by means of an ordinary copying-press, in order to obtain copies rapidly and easily. The copies can be printed off more quickly by thie process than by typography or lithography. About 600 copies can generally be taken from one stencil.