ends crooks to receive the handles of the implements. This is not only a novel but a neat and convenient addition: it certainly enhances the original cost of the fender; not more, however, than it improves the article ; so that, latterly, few of the better sort of fenders have been made without this addition. CHAP. VIII. IRON PRINTING MACHINERY. BRIEF DESCRIPTION OF OLD WOODEN PRESS. -- 66 IMPROVEMENT BY EARL STANHOPE. PERFECTION IN THE MANUFACTURE OF IRON TYPE CON'S MACHINE. To give a detailed account of the invention of the printing press would hardly be more in place in this volume than would be the introduction of an abridgment of the history of typography itself. It would, however, be equally improper to omit, in such a treatise as the present, all mention of an instrument which, whether regarded merely as to the substitution of iron for wood, in the simplest form of its construction, or considered in relation to those complex machines which can only be made of metal, has afforded such large scope for the exercise of ingenuity, and so wide a field of manufacture in the business of ironworking. Until a very recent period, the printing presses commonly used in this country differed but little in their form and materials from those known in Europe very soon after the invention of printing, almost four centuries ago. They consisted of two upright cheeks of wood, with stout-cross pieces, in which worked an iron screw, very similar to that of the fly-press now so generally known to certain tackle, at the lower part of this screw, was suspended a square smooth-faced table of mahogany or other hard wood, occasionally faced with iron, and called the platten, by means of which, when pressed down by the screw, which was itself operated upon by the bar or lever handle, an impression on one side of an interposed sheet of damp paper was taken from the inked surface of the connected mass of types standing under neath it. The form, as it is called, or collection of types, properly arranged and confined by quoins or wedges within an iron frame, denominated a chase, was placed upon a level stone, fixed in a wooden bed or carriage, and made to slide backwards and forwards, upon a sort of railway under the platten, by means of a strap passing over a pulley, underneath the carriage, and connected with a winch handle, placed beside the horizontal parallel rails alluded to. The foregoing, in as few words as possible, is a description of the old-fashioned printing presses formerly found in this country; at least, in most offices beyond the metropolis. These wooden presses are now to be met with only in the lowest jobbing offices: the newspaper and other printers on a large scale invariably using one or other, and often more, of the numerous and excellent iron machines which have been of late years introduced to the notice of the trade. We owe the invention of the earliest signal improvement in the printing press, in England, to the late earl Stanhope, who not only devised the admirable structure, to which his name has been so justly attached, but, as we may say, unintentionally suggested an experiment upon the old wooden presses previously in use, which led to the more general appreciation of the new metal ones. The old press, as already intimated, was made to produce an impression, simply by the action of a common lever upon the screw. One of the most striking improvements exhibited by the Stanhope press was the application of a compound leverage, by means of which the power of the screw was prodigiously increased. The immense advantage thus given, not only to the pressman, but by the improvement of the work produced, and the simplicity of the lever-head, presently induced an application of the new principle to the old presses. It was, however, soon found, that the wooden press was not calculated to sustain the operation of this compound power, especially when applied, as it was, in several instances, without any accurate calculation of its probable effects: and hence the framework of the altered presses constantly gave way, and repeated repairs were rendered necessary. This violent experiment made upon the old machines contributed, along with the obvious superiority of the new ones, to the prompt and general substitution of iron presses for those of wood. Johnson, in his "TYPOGRAPHIA," has figured, and very minutely described, the iron presses in greatest estimation; viz., the Stanhopian, the Columbian, and the Albion. From the very instructive and curious work just named, the author of which was not only an ingenious writer, but an admirable practical printer, most of what follows on the subject of these presses is derived. The annexed cut (fig. 65.) represents the Stanhope press Fig. 65. A is the upright body of the press, called the staple. B, the bottom piece, called, from its figure, the T. Parallel with this piece, and supported by C, the standard or forestay, are two grooved rods, called the ribs, along which the table D slides, so as to carry it under the platten to receive the impression, or to admit of its being thrown out as represented in the figure, in order to have the sheet placed upon or taken off the surface of the types. E, a stout lever-head, eight inches in length, fixed upon an upright arbor, to the lower part of which the bar handle F is fastened. G, a stout leverhead, ten inches in length, fitted upon the main screw, and connected with E by a coupling bar, bolted at both ends with steel cottars. H, the platten, in length twentysix inches; in width twenty inches. It is attached to the lower end of the main screw, with the motion of which it rises and falls: the platten is raised, and the handle drawn back after each pull, by means of the weight I, suspended to a forked lever or balance iron. The table D, already mentioned, and upon which the types are placed, is twenty-nine inches long and twentyfour inches wide; having upon hinges at its extreme end a light frame, K, upon which a piece of vellum, called the tympan, is tightly stretched. To the end of this frame, again, is hinged another, L, called the frisket, having strings across, to assist in keeping the paper against the tympan during the turning down of the latter, and likewise to lift the paper from the types, to which it sometimes adheres pretty closely after the impression has been taken. It may be proper to mention, that these strings pass along the spaces left between the pages of type, and consequently bear only upon that part of the sheet which remains blank after the printing. Iron presses are indebted for no small portion of their great superiority over the wooden ones, to the extreme accuracy with which the corresponding surfaces of the platten and the table are levelled. This is effected by turning them at the lathe, with a sliding rest, with a degree of precision that may be judged of from the fact that, when properly finished, they are expected in every part to bite a hair or a piece of paper. The wonderful precision with which these surfaces act in bringing away, from an area of types equal to the size of one side of a large newspaper, every single line and dot, can only fail to astonish those who, from ignorance alone, think nothing difficult. |