another machine of the same description and on the same plan. This machine will have six printing-cylinders, and will strike off 12,000 copies in an hour!

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Notwithstanding the above astonishing results produced by Mr. Hoe's Machine, yet such is its simplicity, that a few lines will be enough to explain the principle of this wonderful invention. A horizontal cylinder, 1.35 yards in diameter, moves upon an axle which rests in its sockets. One fourth, or thereabouts, of the cir cumference of this cylinder constitutes the bed of the press, in which the chase containing the letters, or type, is placed; the remaining portion of the cylinder is applied for the distribution of the ink, which is put into a receptacle underneath the great cylinder. The feeding-roller takes it off, and, by means of another roller, which has a vibrating, oscillating motion, it spreads it over the form upon the great cylinder. The feeding-roller revolves with a slow and regularly sus tained motion, taking the ink gradually out of the receptacle in which it is deposited. When this large cylinder is in motion, the forms are made successively to come in contact with each one of the four horizontal cylinders, which are arranged at suitable distances round the great cylinder, to print off the four sheets supplied by the feedingrollers. The sheets are laid hold of, direct from the edge of the supplying table, by iron hooks, fixed upon each feeding or depositing cylinder. The receivers of the sheets are supplied by means of wooden frames, which take them from the conducting straps or bands, and place them in a regular pile upon the four receiving tables. In front of each one of the cylinders there are two inking-rollers, which pass over the cylindrical surface devoted to the distribution of the ink, take up the ink upon their own surface, and lay it on the types by the revolution of the main cylinder.

"Four forms are printed off at once by Mr. Hoe's press, each form being in a separate and distinct chase. They are four superficial seg ments of a cylinder, detached from each other, and which are at pleasure attached to or detached from the great cylinder. The usual types are employed on this press; they are fixed upon the great cylinder, and revolve continually, without any danger of becoming loose, being retained in their place by a plan peculiar to this press. The great central cylinder, on which the forms are fixed, revolves from left to right; whereas the four others, or pressing-cylinders, revolve from right to left. The paper is placed by the workmen in such a manner that it slips between the two cylinders on one side, and comes out, perfectly printed, on the other side, when, by means of suitable straps and bands, the sheets are arranged in a pile, under frames, which rise and fall alternately."

La Patrie also makes a curious calculation of work done by this press:

"The journal La Patrie, contains about 4,320 lines; 8,000 copies make 34,560,000 lines. A scribe could write about three lines in a minute; therefore, it would require 11,520,000 minutes, or 192,000 hours, for a single scribe to supply 8,000 copies of La Patrie; or, in other words, it would require 192,000 men to supply, by copying, the

same amount which Mr. Hoe's press supplies in one hour! Thus his press accomplishes as much as it would take the half, at least, of the whole French army to supply!"

CHEMITYPE PRINTING.

ANOTHER species of engraving has been brought before the public, to which the name of Chemitype Printing has been given. By this method an etching or engraving, made in metal in the usual way, may be converted into a high-relief stamp, to be used in printing on an ordinary press, as is the case with common wood-engravings. The following statement may in general illustrate the character of the invention. On a highly polished plate of pure zinc an etching or engraving is made in the usual manner, which, under common circumstances, would be fitted for impressions on an engraver's press, having the same harmony and proportion of all the respective etched or engraved lines. The tracery, thus deepened, is now to be fused or melted down with a negative metal, and the original metal plate (zinc) corroded, or etched, by means of a certain acid, thus making the characters of the former drawing appear in the shape of a highrelief stamp. This effect is only produced in consequence of the metal composition in the lines of the tracery not being acted upon by the acid, on account of the galvanic agency subsisting between the two metals, and the acid corroding only the zinc.

After these details, there cannot be the least doubt of the specific difference between the chemitype printing and glyphography, relief etching in copper, and other similar artistical processes and practices lately invented. Its principle rests upon the positive and negative nature of the metals. As every drawing on the metal plate is completely exact on the relief stamp, the practice is absolutely independent; the exact and accurate representation of the original sketch is always to be expected. Wood-engraving cannot, in most cases, be superseded by this novel method; but in many other instances the new practice is preferable, chiefly when colored printing is required, in the representation of maps, plans, architectural drawings, &c. &c. At the same time, the correction or improvement of any drawing can be much better executed than in wood-engravings.—Scientific Ameri

can.

IMPROVED MACHINE FOR PRINTING WALL-PAPER.

THE inventors of this new machine for printing wall-paper, oil-cloth, &c., are Messrs. Gould & Shaw, of Newark, N. J. The machine is so made as to give to two blocks, placed in two plattens, an intermittent, reciprocating motion, so that two impressions are made during the forward and backward stroke of the piston that moves the blocks. It also supplies the blocks with color from two boxes, as well as feeds in the paper or material to be printed, and takes it away. The principal machinery consists of two long tables, transverse to each other, one being the feeding-table, and the other the printing-frame. At the end

of the latter is a large drum, with a projecting eccentric flange, or rail, fastened to its periphery. The head of the piston, which moves the blocks, grasps this rail, but is guided in a straight line by a guiderest, so that when the drum revolves, the piston-rod will be guided backwards and forwards by the angular part of the rail, but it will be stationary while that part of the rail around the end of the drum is passing through the jaws of the piston-head. This gives the pistonrod and blocks attached an intermittent reciprocating motion. The printing-blocks are secured to the plattens on the inside, but the latter are placed a little distance below the paper, and are secured to coiled springs at the corners, which allow the blocks to be pressed down, but raise them up when the pressure is removed. The plattens, therefore, have square stationary frames around them, all connected together, and slide along on the table guided by up-raised rails on each side, which fit into grooves in the platten-frames. From the framing above, three spring pistons are suspended, which are forced down on the plattens to make the impressions during the intermissions of the blocks. There are, therefore, four cams on the shaft above, the middle ones being double and the other two single. The side cams alternately press down one block on to color cushions to supply it with color, and the middle ones press down the block which makes the impression, so that the motion of the cams coincides with that of the piston-rods. Thus much for the operating of the blocks. The paper is fed under the blocks on the cross-table, between guideplates. The paper passes through to a small catching-bar, which has a vibratory motion, and catches and lets go, to draw the printed paper from under the blocks, and to feed in unprinted paper for the next impression. The catching-bar is operated by crooked levers, secured to one of the block frames, and oscillating on a pivot fixed on a block of the feed-table. All the motions are thus in harmony with that of the drum which works the whole. For certain kinds of work the advantages of this machine are apparent.-Scientific American.

MANUFACTURE AND USE OF COPPER TYPE.

A MACHINE has been invented and patented in England, for the manufacture of printing-types, without fusing the metal and pouring t into moulds. The inventor, Mr. Petit, effects his process by the ase of steel dies and matrices, which, by means of powerful pressure, impress the letters and characters on copper, fashioned into quadrangular strips of an indefinite length, wound round a cylinder; The type being struck, or punched, the same moment that its size is nathematically determined. The machine exhibited to the Royal Society, in June last, produced 32 types per minute; but by the apalication of a small steam-engine to the type-making machinery, it is estimated that 60 per minute can be struck, or 36,000 per diem. The types thus produced possess the utmost sharpness of outline and hardness, in consequence of the superiority of the metal employed and the pressure to which they have been subjected. The hardness

of ordinary copper over type-metal is in the proportion of 100 to 1, and the density of the copper used in the manufacture of type is considerably increased by the compression which it undergoes in the machinery. A London firm, employed to print stamps for government, is in the habit of using raised copper surfaces for the purpose; no less than 125,000,000 impressions having been taken from a single plate. It is impossible so say, at present, to what extent the new type will surpass that in use, as regards durability. They can, however, be produced much cheaper than even under the pres ent system. In proportion as founts of type decrease in size, they rise in price, but a decrease in weight, under the new system, will be accompanied by a diminution in cost; and when, ultimately, the sharpness and clearness of the type has been, by long use, deteriorated, the metal will retain an intrinsic value far above what the present composition of metals now used for printing-types does in similar cases. The machine has received the name of the Apyrotype, and is undoubtedly one of the most important and most desirable inventions of the year.

IMPROVEMENT IN GRAIN-SEPARATORS.

THIS machine is the invention of Benjamin D. Sanders, of Virginia, and it is designed to separate the impurities in threshed grain, upon a different principle from that of the common grain-separators. Instead of forcing the chaff from the good grain by means of a blower, a vacuum is created, the power of which can be regulated at will, by which every thing specifically lighter than the good grain is raised up into a receiver, while the latter is not raised off from the screens, but passes over them, and falls into a granary below. As soon as the vacuum is created, a current of air rushes from below, and its force must be regulated according to the height to which the impurities are to be raised. The good grain is thus deposited in a granary by itself, while that which is light is forced up into a receiver, and the chaff is entirely driven out from the machine.—Scientific American.

COTTON-SEED EXTRACTOR.

THIS new invention of Mr. Stephen R. Parkhurst is said to be the most perfect machine of the kind, and will prove of the greatest advantage to all branches of the cotton manufacture. The machine is of the simplest construction, and it seems a wonder that the idea had not been long since suggested. It is composed mainly of two cylinders, closely set together, a feeder, and the ordinary fan. The cotton containing the seed is thrown on the feeder, from which it is taken by the cylinders, which extract the seeds whole, the cotton being passed by the fan into a receiver. The quantity of cotton cleaned by this machine will far exceed that of the ordinary saw-gin now in use, and a third less power is required to keep it in operation. By this method the texture and length of the fibre are completely preserved, the value of the cotton will be greatly enhanced, and the intrinsic worth is increas

ed from a cent to a cent and a half per pound. It is calculated, that a thousand pounds of cotton can be extracted in the same space of time that is required to extract twenty-four pounds by the common saw-gin. The machine may be worked for ten years without requiring repair. -New York Farmer and Mechanic.

STEAM-PLOUGH.

A SERIES of experiments on the application of steam-power to the plough has lately been made near Reading, England. Some practical and scientific gentlemen were present, and expressed their gratification at the success of this important improvement in the working of the plough. It can be used on any kind of land.

IMPROVEMENT IN MAKING FLOUR.

D. P. BONALL, of Tecumseh, Michigan, has recently made an improvement in the process of manufacturing flour, which is claimed to be valuable. The Indiana State Journal publishes the following extracts from a letter written by Mr. Bonall in reply to inquiries made of him in reference to the improvement:

"My improved process of milling' consists in separating the starch part of the wheat from the glutinous matter, and submitting the latter to a second grinding. The way it is effected is by placing an auxiliary run of stones so as to receive the entire body of the 'offal,' on its passage from the upper or first merchant-bolts. The stones are fitted to run from 300 to 400 revolutions per minute, and the feeding of the stuffs is made uniform and perfect by a very simple combination of machinery. After the offal' is thus ground, or severely scoured, it is then passed into the lower bolts, or dusters, when the flour is taken out and sent to the cooler,' or first bolts, to be uniformly mixed, in regular proportions, with the superfine flour, and the remainder separated for feeds.

"The advantage obtained by this mode of grinding is as follows. 1st. It enables the miller to grind high, or coarse, at the first grinding, and thus avoid injury to the starchy' portion of the wheat, and insures free, good bolting, which is not always the case when attempting to grind the starch and 'gluten' contained in the grain to the same consistency by one process, as the starch, which pulverizes easy, is apt to be too fine, and stick to the bolts, or else the farina' is too coarse and goes to middlings, or adheres to the bran, and is lost. 2d. It enables the miller to grind wet or damp wheat better than any other mode, as the first grinding, which is high and free, warms the wheat, where, by elevating, cooling, airing, and bathing, the moisture is principally evaporated, and the offal' is partially kiln-dried, when, by submitting it to the quick grinding or scouring process, the flour is almost entirely whipped out' and put into the superfine barrel. 3d. It catches all the broken particles of grain that escape the first grinding by stopping and starting, or from other causes, and equalizes the grinding, when any variations occur in the first mills or grind