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English: The paper-making machine is constructed to imitate in a great measure, and in some respects to improve, the processes used in making paper by hand ; but its chief advantages are the increased rapidity with which it accomplishes the manufacture, and the means of producing paper of any size which can practically bo required.

By the agency of this admirable contrivance, which is so adjusted as to produce the intended effect with unerring precision, a process which, in the old system of paper making, occupied about three weelis, is now performed in as many minutes.

The paper-making machine is supplied fiom the "chest" or reservoir f, into which the pulp descends from the beating engine, when sufficiently ground ; being kept in constant motion, as it descends, by means of the agitator g, in order that it shall not settle. From this reservoir the; pulp is again conveyed by a pipe into what is technically termed the "lifter" H, which consists of a cast-iron wheel, enclosed in a wooden case, and having a number of buckets affixed to its circumference. The trough i, placed immediately beneath the endless wire k, is for the purpose of receiving the water which drains away from the pulp during the process of manufacture; and as this water is frequently impregnated with certain chemicals used in connection with paper-making, it is returned again by a conducting spout into the "lifter," where, by the rotation of the buckets, both the pulp and back-water become again thoroughly mixed, and are together raised by the lifter through the spout L, into the trough m, where the pulp is strained by means of a sieve or "knotter," as it is called, which is usually formed of brass, having fine slits cut in it to allow the comminuted pulp to pass through, while it retains all lumps and knots ; and so fine are these openings, in order to free the pulp entirely from any thing which would be liable to damage the quality of the paper, that it l)ecomcs necessary to a])ply a means of exhaustion underneath, in order to facilitate the passage of the pulp through the strainer.

The lumps collected upon the top of this knotter, more particularly when printing papers are being manufactured, are composed, to a considerable extent, of india-rubber, which is a source of much greater annoyance to the papermaker than is readily conceived. For, in the first place, it is next to impossible in sorting and cutting the rags to free them entirely from the braiding, and so forth, witn which ladies adorn their dresses; and in the next, the bleach failing to act upon a substance of that character, the quality of the paper becomes greatly deteriorated, by the large black specks which it occasions, and which, by the combined heat and pressure of the rolls and cylinders, enlarge considerably as it proceeds.

Passing from the strainer, tlie pulp is next made to distribute itself equally throughout the entire width of the machine, and is afterwaids allowed to flow over a small lip or ledge, in a regular and even stream, whence it is received by the upper surfiice of the endless wire k, upon which the first process of manufacture takes place. Of course the thickness of the paper depends in some measure upon the speed at which the machine is made to travel ; but it is mainly determined by the quantity of pulp allowed to flow upon the wire, wliich by various contrivances can be regulated to great nicety. Paper may be made by this machine, consideral)ly less than the thousandth of an inch in thickness, and although so thin, it is capable of being colored, it is capable of being glazed, it is capable of receiving a water-mark ; and what is perhaps still more astonisliing, a strip not exceeding 4 inches in width, is sometimes capable of sustaining a weight of 20 lbs., so great is its tenacity.

But, to return to the machine itself. The quantity of pulp required to flow from the vat m being determined, it is first received by the continuous woven wire K, upon which it forms itself into paper ; this wire gauze, which resembles a jack-towel, passing over the small copper rollers n, round the larger one marked o, and being kept in proper tension by two others placed underneath. A gentle vibratory motion IVom side to side is given to the wire, which assists to spread the pulp evenly, and also to facilitate the seiiaration of the water, and by this means, aided by a suction pump, the pulp solidifies as it advances. The two black squares on either side of the "dandy" roller p indicate the position of two wooden boxes, from which the air is partially exhausted, thus causing the atmospheric pressure to operate in compacting the pulp into paper, the water and moisture being drawn through the wire and the pulp retained on the surface.

Next, we have to notice the deckle or boundary straps Q, which regulate the width of the paper, travelling at the same rate as the wire, and thus limiting the spread of the pulp. The " dandy " roller p is employed to give any impression to the paper that may be required. We may suppose for instance, that the circumference of that roller answers exactly to the length or bieadlh of the wire forming a hand mould, which, supposing such wire to be fixed or curved in that form, wouki necessarily leave the same impression as when employed in the ordinary way. Being placed between the air lioxcs, the paper becomes impressed by it when in a half-formed state, and whatever marks are thus made, the paper will effectually retain. The two rollers following the dandy, marked R and o, are termed couching rollers, from their performing a similar operation in the manufacture of machine-made papers to the business of the coucher in conductmg the process by hand. They are simply wooden rollers covered with felt. In some instances, however, the upper couch roll r is made to answer a double purpose. In making writing or other papers where smalts, ultramarine, and various colors are used, considerable difference will frequently be found in the tint of the paper when the two sides are compared, in consequence of the coloring matter sinking to the lower side, by the natural subsidence of the water, or from the action of the suction boxes ; and to obviate this, instead of employing the ordinary couch roll, which acts upon the tcpper surface of the paper, a hollow one is substituted, having a suction box within it, acted upon by an air pump, which tends in some measure to counteract the effect, justly considered objectionable. Merging from those rollers the paper is received from the wire gauze by a continuous felt s, which conducts it through two pair of pressing rollers, and afterwards to the drying cylinders. After passing through the first pair of rollers the paper is carried along the felt for some distance, and then turned over, in order to receive a corresponding pressure on the other side, thus obviating the iuequality of surface which would otherwise be apparent, especially if the paper were to be employed for books.