Among the bed and platen presses, the most valuable and most extensively used, are those manufactured by Mr. J. Adams, of Boston. Mr. Adams took out a patent in 1830, for a power-press, and in 1886 another for an improved power-press. The number of improvements claimed in the specification of this latter patent ex ceeded twenty in number, sonic of which were as ingenious as they were novel. Mr. Adams's press was the first in this country to which a fly frame was attached. It requires but one person (a woman) to tend it and put the paper on the register pins ; from which it is removed by the fingers or clips which carry it along un der the platen, where it remains fur a second to receive the impression of the type. The latter, placed upon a movable bed, travels on to receive the ink from the self-acting rollers, returns, and when im mediately below the platen is carried upwards by the action of a crank under neath, and is pressed against the surface of the paper : it is then lowered, passes against a side table, inked, returns, and renews the operation. The impressed sheet is carried horizontally on tapes some distance, when it has to riscan inclin ed plane of tape to come within the reach of the fly frame. The attraction from the horizontal to the ascending direction is ingeniously effected by means of a bellows acted upon by the press itself; which blows the leaf up at the edge, and thus raises it over the first difficulty, that of altering its direction. It is removed from the tapes by the fly frame. The whole is effected with great rapidity and little noise. It throws off more work than any English press of a similar kind, the larger size printing readily 600 copies per hour. It is adapted for stereotype and letter-press, as well as wood-eut punting. The cylinder press is the great in vention of the day for fast printing'; and it is made with a small or large cylinder, according as it is to be used for newspa per or book work, the former being most favorable to rapid printing, and the lat ter to good impressions. it has self-ink ing rollers, pointing apparatus, and a sheet-flyer. INThen it is to be worked at its greatest speed, it must be impelled by a steam-engine, and then 2,500 impres sions of a form of 42 by 26 inches may be conveniently taken in an hour, and pos sibly 8,000, if thepaper can be fed to it by one person so fast. When it is driv en by a man with a crank and fly-wheel, 800 impressions of the same form may be taken in an hour, and the work of feed ing the press with paper at this rate may be done, and usually is done, by a boy or female. All cylinder presses, however, are intended to be used for rapid work occasionally, if not usually, and are there fore made with heavy frames and strong working parts, to endure the rapid mo tion and the sudden reverses which at tend the printing of 50 impressions in a minute or 8,000 in an hour.
Front the preceding statement it thus appears that when two persons work either of the above presses, the band-press gives 250 impressions, the platen power-press 400 impressions, and the cylinder press 800 impressions, per hour : the platen power-press, though much heavier than the hand-press, giving double its number of impressions by a better application of manpower; and the cylinder press giving four times its num ber of impressions by a still better appli cation of the same power on a lighter ma chine ; the difference in the movement of the respective presses being pretty fairly represented by saying, that the band-press is in actual motion one-third of its time, the platen power-press two thirds, and the cylinder press all its time, the first and second dwelling upon the impression of the whole form with great force, while the latter rolls over the form lightly, impressing only about an 80th part of it at once.
The PICIIVPING MACnINE, is the adap tation of the printing-press to the moving power of steam. The types are laid on a stage, imposed in the usual manner, first one side of the sheet, and then, a little beyond it, the other side. They are ink ed by passing under rollers which are supplied with ink from above. The paper is then placed on a large roller by a boy, and the roller turning passes and presses the paper over the type, producing a per fect impression on one side. The sheet is then reversed by small rollers and car ried to the next roller, which turns it over the other form of type and perfects when a boy removes it. During this time the first boy had laid another sheet off the first roller, the types had returned under the rollers, and received fresh ink from the ink rollers, the first roller had turned, the two small rollers had laid the reversed sheet on the second roller, which had turned and perfected it, and in the 9th or 12th of a second of time the last boy receives another sheet. The number perfected being from 2,000 to 3,000 per hour, or 20 times the number by ordinary press-work, performed by two hands and a boy.
The printing-machine was invented by Mr. Konig, a Saxon, who considered that steam might be employed with advantage to expedite the process of printing ; but not receiving encourage ment on the Continent to enable him to prosecute his plans; he came to England in 1804, and, after explaining his views to some of the principal printers in Lon don, Mr. Bensley, Mr. Woodfall, and Mr. Taylor, embarked in the undertaking, but Mr. Woodfall soon withdrew. After in numerable experiments, and a great outlay of capital, the result was not satisfactory ; but the experience gained by prosecuting these experiments resulted in the produc tion of a machine to print with cylinders instead of a flat surface, as was the case with the printing press, which was limit ed- in the size of the paper by the size of the press and the power of the pressman. In cylindrical printing, by which the pressure is communicated in lines, the size may be very considerably increased.
The first machine that was constructed was capable of printing 1000 copies per hour of double dewy paper on both sides; while a hand-press is estimated to print 250 copies of a single sheet on one side only, in the same time.
When this machine was completed, the proprietors of the Times newspaper, ever ready to adopt any improvement that would expedite its publication, with out regarding expense, agreed with the patentees for two machines, and on the 28th of November, 1814, the Times was published, executed by cylindrical print ing, the moving power being steam ; these were the only machines construct ed under the first patent—they threw off 1,800 per hour.
In 1815, Mr. Cowper, of England, ob tained a patent for curving stereotype plates, for the purpose of fixing them on a cylinder. Several machines so mounted, capable of printing 1000 sheets per hour upon both sides, are at work at the present day ; twelve machines on this principle having been made for Directors of the Bank of England a short time previous to their re-issuing gold.