with all the other apparatus for laying the yarn upon the spindles, &c. This last method cannot be used to advantage in any case, but may be substituted for either of the three methods described above for spinning yarn for sail cloths, sackings, tarpaulins, or other coarse or heavy goods.

WEAVING.

In the preceding articles, cotton, wool, silk, and flax, we have traced the process of forming the four commonest fibrous materials to the state of thread or yarn, and now purpose, in general terms, to treat of their further destination in the formation of the various superficial structures termed web or cloth.

The structures which come under the name of cloth are formed of two distinct layers of yarns, generally crossing each other at right angles, termed the warp, and the woof or weft; and as all cloths, however varied, are constructed of these two distinct portions of threads, the mind will, when made to comprehend the mode and form of loom used in the weav ing of one material, be able easily to conceive its application to other sorts, varying only in dimensions and strength, according as the weight of the yarn or size of the cloth may demand.

Prior to commencing the weaving of any material, it is necessary to prepare the yarn for the loom, one process of which preparation is, in fact, the measuring and arranging the threads that are to compose the warp in a parallel direction, termed warping.

The warp, or that layer of threads which extends the length of the piece to be woven, requires the most attention in the preparation. To form a warp, it is necessary to be very particular in the number and quality of the yarns; for upon their fineness, length, and breadth, depend the fineness, length, and breadth of the piece to be woven. Though this may appear a very simple operation, yet, the performing of it with expedition and accuracy demands sonie mechanical skill. The machine for effecting this object is termed the warping-mill, and, though considerably larger, may be compared to the reel described in the cotton manufacture: but the spindle upon which it revolves is placed perpendicularly. The reel cannot easily be made of such dimensions that a thread measured upon its circumference shall be equal to the required length of the warp; and consequently the layer of yarns is placed in a direction parallel to the axis of the reel,

and wound upon it in a spiral direction till they arrive at the upper end, when the motions of the mill and the yarns are reversed, and a fresh layer is placed upon the same parts of the reel. By this method of plying the layers of yarn, it is obvious, that a small number of ends may be doubled so as to form the required breadth of the warp. If the twist is spun on cops, it must, prior to warping, be wound on bobbins, which bobbins are placed in a frame to be wound off upon the warping-mill.

The next operation to be effected in the manufacture of cotton goods is that of dressing the warp; that is, impreg nating it with certain gummy or gelatinous matter, and coating the surface of the yarns, to enable the warp to sustain the abrasion to which it is subjected in the process of weaving, as will be seen when that process is described. In preparing the wool and silk yarns for the looms, dressing is in general only required for the finest sort, when a little mucilage of gum arabic, or of jelly made from rabbit or other light skins, is used to increase in a slight degree the tenacity.

As it is of considerable importance in the dressing of warps to have the materials dispersed equally over the surfaces, many ingenious mechanics have constructed machines for that purpose; the general principle of which are the placing of the warp on a roller, and immersing it in the mucilage, which allows it to be drawn off covered with mucilaginous matter. The superfluous mucilage is brushed off, and the yarn is put in a frame, and by means of revolving fans is dried and rendered fit to be put in the loom. In cases where the manufacturer operates separately, the weaver dresses the warp, by extending and carefully brushing it over with paste, and drying it in the air, prior to placing it in the loom.

Before we proceed to give a description of the looms used in the manufacture of cloth, it is requisite that the reader should be acquainted with the various sorts of structure arising from the different dispositions of the warp and weft, termed fabric.

The simplest mode of disposing of the warp and weft is called common fabric; and taking into account the quantity of yarn used for a given superficies of cloth, is certainly, so far as respects its strength and durability, the most advantageous mode of distributing it.

Fig. 412 is a section of a piece of cloth wove in the common fabric. The circles represent the warp in section, and the weft is seen passing alternately above and below each succeeding yarn, and the return, or next

THE OPERATIVE MECHANIC

layer of weft, passing beneath those threads over which it had passed before, and vice versa.

Fig. 413 represents a section of a piece of cloth wove to a twilled pattern. In this the yarn of the weft passes alternately over four and under one of the threads of the warp, and vice versâ in its return.

Fig. 414 represents the section of a dimity or kerseymere, in which the weft passes over four and under four, then over one and under four, and over four and under one, which places it in a position to begin again; when the passage of the weft, as it regards the warp, is exactly reversed.

Fig. 415 shows the construction of a double cloth woven with two warps. This mode of weaving is mostly applied to the construction of carpets, and the transposition of the colours in the pattern arises from it. All the divers modes of passing the weft among the warp may be introduced in this figure, and whatever is effected with one web of warp is alternately effected with the other, as may be seen by the figure. It is therefore easy to conceive, that all the various patterns in woven goods are obtained by differently disposing of the warp, that is, lifting a greater or smaller quantity of it at a time, which places the weft on either surface of the cloth at pleasure.

The common loom, or that which is destined to weave cloth of the common fabric, is the most simple in its construction, as the mode of lifting and depressing the portions of the warp are similar at each throw of the shuttle. A top view of a loom of this description is given in fig. 416.

A is a warp.

B a roller upon which the warp is wound, called the yarn-beam, and applied to maintain the warp in a stretched position by means of a lever passing through one of its ends and tightened with a string, as will be more clearly understood by referring to the perpendicular section at No. 2 of this figure.

CCC are rods placed between the threads of the warp to keep them separate, so that they may pass forward clear of each other, when the warp is fed forward and filled with the weft, these rods are at different periods moved towards the warp-roller B.

At D are the heald or heddles, formed of two rods, one above and the other below the piece, and connected together by numerous strings, through which distinct portions of the warp pass, and by means of the treadles below are lifted and depressed. A detached view of two leaves of a heddle is represented in section in fig. 417.

a a, a1a', are the top and bottom bars, and the two lines a2 a represent two adjacent yarns of the warp, so that when a a rises it carries with it one thread, while the other thread which is passed through the lower loop of this heddle is depressed by the other heddles. The next part, E, fig. 416, is a frame to carry the reed, called the lay. A portion of the reed is shown detached in fig. 418. It is, except when used in cloth of the coarsest description, formed of flatted wires, placed parallel to each other, and governed, as to their thickness and adjacency, by the fineness of the fabric in which they are to be used.

The lay, fig. 416, which carries the reed, is hung from a bar capable of vibrating on gudgeons in the upper frame of the loom. The two thin elastic pieces of wood which suspend the lay are called swords, and may be seen at F1, F1, fig. 419. The reed thus hung is just beyond the line of the shuttle-flight, and has one or two threads of the warp passed between each of its wires, which wires are termed dents. Its use is to strike home the thread of the weft immediately after it has been delivered by the flight of the shuttle; it is therefore pushed by the weaver towards the yarn-beam,

prior to each flight of the shuttle, and when the weft has been delivered, it is allowed to return and strike home that individual thread.

The next part of the loom is the shuttle-boxes, which are placed at F, F. In weaving narrow goods, the shuttle is passed between the warp by the hands of the weaver, but when the cloth is fine, or of a breadth to preclude this mode, the fly-shuttle, which is much more compact, and has a spindle to carry a cop upon it, is introduced. This form of shuttle is represented in fig. 420. The shuttle with its cop is placed in the shuttle-box, which is of dimensions just sufficient to receive it. In fig. 419 is represented the reed and lay at F2 F2. The shuttle is driven to the opposite boxes by means of a small piece of wood, called a driver, which lies behind the shuttle in each box, and is capable of being swiftly drawn forward by a string attached to it, and connected with a handle, G. The weaver holds the handle in his hand, and by a jerk throws the shuttle across the web into the opposite box, and then, by bringing the lay towards him, strikes home the weft. The flight of the shuttle requires adjustment or skill, as its impetus must be proportioned to the weight of the yarn which it carries, and the freedom with which the cop unwinds.

If two or three colours of weft are to be put into a piece, so as to form a pattern, there are two or three shuttles to be thrown; in such case, the shuttle-boxes are formed in three parts, as represented by the dotted lines. This combination of shuttle-boxes is capable of being moved upwards and downwards upon the lay by the small levers, H, H, fixed upon the swords, and worked by the handle I, so that the shuttle to be thrown may be brought opposite to the division in the warp through which it is to fly.

As the cloth is perfected, it is led over the breast-beam K, fig. 416, and is, by means of a ratchet wheel, wound upon the roller L, which is termed the cloth-beam. At m is a stretching-rod, formed of two pieces, and lashed with a piece of band, in such manner, that the ends are forced outwards, as may be seen in the figure. This rod has small points at each end, which pass through the selvage of the cloth, and serve to keep the cloth stretched, as otherwise the action of the weft would occasion it to pucker and lay in hollows. The weaver sits behind the breast-beam, and in fine work, where the breast-beam is dispensed with, behind the cloth-roller.

Such is the construction of loom used in plain-weaving; and by examining it attentively it will be seen, that by an additional number of heddles any required movements of the warp can be effected, and by varieties of weft other diversifications attained almost to infinity. The greatest skill required in the act of weaving by hand is the directing of the flight of the shuttle, where the impetus given should just suffice to deliver it in the opposite box. The striking home of the weft should be done with a regular force, and the preparatory operations carefully attended to, that the warp may wind off freely and regularly with an equal tension in all its parts.

From an examination of the movements of so simple a machine as the loom, the mechanist will instantly conceive the practicability of applying power to produce the necessary movements; we shall, therefore, present the reader with two combinations of this class which are called power-looms: the first invented by a Mr. Millar.

Fig. 421 represents a section of a power-loom, in which all the operations are effected by means of treadles, moved by wipers or eccentrics.

A, the main shaft, to which the power is communicated, carrying the wipers, one of which is seen at A. A1, the yarn-beam; B, three rollers, on the lower of which the cloth is wound after passing above and between the two upper ones; C, C, the heddles; D, D, the treadles, to which the heddles are attached by means of a line passing over a pulley, in such manner, that the depression of one heddle occasions the raising of the other; E, E, the lay carrying the reed; the motion is given to the lay by a wiper moving a treadle that is attached to the lay by means of the line and crank at F. The return motion for striking home the weft is given by a weight hanging over a pulley, as may be seen in the figure. The flight of the shuttle is occasioned by attaching the strings from the drivers to another treadle, which treadle is worked at the proper periods by another wiper.

Another form of power-loom, called the crank-loom, is used, and varies from the preceding in the mode by which the movement is given to the heddles. In this construction of loom the revolving shaft is placed immediately under the heddles, which are suspended over a pulley similarly to the loom last described; but the motion is given to them by means of their being attached to two opposite cranks on the shaft. The motion is given to the lay by a crank upon another shaft, which is made to revolve twice, while the shaft that moves the heddles revolves once. By this, it is evident, that the warp is opened, and the shuttle thrown twice, during one revolution of the first shaft.

The flight is given to the shuttle by the cords of the drivers being attached to an upright lever, as represented in fig. 422.

The cords, c, c, of the drivers are attached to the lever, e, which, by means of the arms, h, i, is caused to vibrate in opposite directions upon the centre, g, being alternately struck, by two projecting pieces upon the first mentioned crank-shaft, which causes the lever, e, to vibrate in a plane parallel to the crank-shafts, and gives flight to the shuttle, at the period when the warp is opened.

In either of these plans for working looms by power, if the number of heddles is required to be increased, in order to produce any figure, it is easily effected, by varying the number and the position of the cranks or wipers.

But, though great variations in the movements of a warp may be effected by using many heddles, yet when the number of heddles and the number of cranks are increased, great objections arise to their being used; consequently, another construction of loom, called the draw-loom, is introduced when complicated figures are to be woven. In this loom the changes are effected by raising one portion of the warp entirely out of the way, while the other is wrought by the heddles at the time it is being filled with the weft; the