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. A, 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

part raised is then lowered into work, and other yarns of the warp lifted out of the way.

A loom on this principle is shown in fig. 423. For weaving carpets by this method, every yarn of the warp has a line attached to it, which lines are brought together in one connected piece, according to the portion of warp to be raised at once, and carried over the pulleys as at A, and attached to the fixed beam at B. This portion is called the tail. Below the warp these lines, which are called the simples, are kept in a state of tension by weights, as at C; and in order to keep them distinctly apart, are made to pass through a board perforated with holes at D. Other lines are attached to the tail, capable of being pulled by handles, as at E, by which means, such portions of the warp as are required can be raised. By this contrivance the greatest intricacy of pattern can be attained; but the attaching of the simples to the different parts of the warp, by means of small eyes of metal through which the threads of the warp are made to pass, is a work of considerable labour. Damask table-cloths are produced by this loom.

It would occupy too inuch room were we to enter with more exactness into the great variety of looms which ingenuity has constructed; what we have said therefore we trust will be sufficient to convey to the reader a perfect knowledge of the principles of forming those various fabrics which are termed cloth. In the weaving of ribands and other ornamental works, many extraneous substances, totally unconnected with the warp or weft, are thrown in, which affords the designers an additional scope for the display of embellishments. These substances are merely held in the fabric by the intersection of the two staple parts, the warp and the weft, and are by the weavers denominated whips.

In the formation of cloth from the yarn of cotton, silk, hemp, and long wool, denominated worsted, the fabric when taken from the loom is, so far as regards the weaving, in a perfect state; the further operations, both mechanical and chemical, which it undergoes, may properly be considered as tending merely to its further embellishment. These operations consist generally of singing the superfluous fibres from the surface of the cloth, by drawing it over hot irons, and after bleaching or dying, submitting the cotton and linen goods to pressure between heavy iron cylinders, for the purpose of giving it a gloss, and the worsted, called camblets or stuffs, between warm copper-plates, called hot-pressing, to give it a smooth and finished appearance.

In the formation of cloth from short wool, of which our wearing apparel is made, the loom cannot be said similarly to have completed the operation. In this branch of manufacture, the yarn is woven in a common loom in the manner we have shown, and called common fabric, but when the piece is taken from the loom the web is too loose and open,

and is consequently submitted to another operation, called fulling. The cloth, after it is, by repeated washings, divested of the oil that was put in it in the act of carding the wool, is taken to the fulling-mill, where it is immersed in water, and subjected to repeated compressions by the action of a large beater formed of wood, which repeatedly changes the position of the cloth, and by its continuous action causes the fibres to felt and combine more closely together, so that the beauty and stability of the texture is greatly improved. The cloth is next submitted to the dyer, if so destined; but in many colours for the best cloths this process is effected in the wool prior to the commencement of the manufacturing.

The cloth then undergoes the operation of the gig-mill, which is formed of a cylinder, somewhat similar to that of a carding-engine, covered with the heads or burs of a large species of thistle, called teasels. This engine is used to raise the fibres or nap, and lay it in a parallel direction, which, in fine cloth, is cut off by shears, and the cloth then undergoes hot-pressing to bring it into a state fit for the market.

Upon considering the various methods of fabricating cloth in general, it may easily be conceived, that great scope is afforded to the practice of dishonest modes of forming fabric apparently valuable, such as the introducing of weft or warps of different qualities and hiding them by the mode of plying the other part. In trying the strength of cloth it should always stand both in the direction of the warp and the weft; and the substances of which all parts are formed should be known by separate examination, and not by mere superficial inspection, as the surface may easily be formed to hide defects, and display apparent value.

ROPE-MAKING..

IN rendering the hemp-plant proper for the uses of the rope-maker, it has to undergo a variety of processes.

The first of these is retting, that is, exposing it to the action of the dew, or water; the former termed dew-retting; the latter, by which the finest hemp is produced, waterretting. In both or either of these processes, the quality of the hemp is said to be influenced by the state of the weather, and the finest to be produced when showers have mostly prevailed.

In dew-retting, the hemp-stalks, immediately after being =pulled, are spread out, in a thin, even, and regular way, so as to keep exact rows, on a fine level piece of close old sward land, for the space of three, six, and sometimes eight weeks, as circumstances may require; during which, they are turned two or three times in the week, according to the state of the atmosphere.

The motive for thus spreading it out upon the ground is, that the dew, by penetrating into the plant, may render the separation of the rind from the stem or bur easy to be accomplished. When the dew has acted upon it sufficiently for this purpose, it is tied up into large bundles, and carried home and slacked, or otherwise it is put into a covered building, till wanted to be formed into hemp.

This process, called grassing, requires great nicety and attention, that the texture of the hemp may not be injured either by too long continuance on the sward, or by being removed before the hempy substance is rendered sufficiently separable.

In water-retting, the much more common and speedy method is, to tie the hemp-plant into small bundles, by means of bands at each end, and in general to deposit it bundle upon bundle, in a direct and crossing manner, in a pond of standing water, to form what is called a bed of hemp. This bed, when formed of as great a thickness as the depth of the water will admit, which some think can hardly be too great, though five or six feet are the usual depths, is loaded with large pieces of heavy wood until the whole is immersed in the water. In choosing ponds, those should be preferred that have clayey bottoms.

When the hemp-plant has remained in the water for about five or six days, varied according to the nature of the pond and the state of the weather, it is taken out, and conveyed to a piece of mown grass or other sward land, which is free from all sorts of animals. Here the bundles are untied, and the hemp-stalks spread out thin, stem by stem. While in this state, especially in moist weather, they must be carefully turned every second day, to prevent their being injured by the worm casts. In this way they are kept for about five or six weeks, when they are gathered up, tied in large bundles, and kept perfectly dry in a house or small stack, till wanted for use. In some of the northern parts of Scotland, the hemp, after it has been pulled, and cleared of its leaves, seeds, and branches, by means of a ripple, is formed into bundles of twelve handfuls each, and steeped in a manner similar to flax,

till its reed becomes capable of parting from the bark In this process, it is favourable to give it rather too much than too little of time; and let it be observed, that the most slender hemp requires the greatest length of time in the water. Where the quantity of hemp is only small, the hempy part may be separated from the reed by hand-labour; but where it is large, drying and breaking it in the manner of flax is strongly recommended.

After the hemp has been taken out of the water, it is not spread out upon the grass-ground in the way of flax; but set up in an inclined position against cords arranged for the purpose, or by any other method by which it can receive the full benefit of the air till it be perfectly dried, which may be known by its rising in blisters from the boon. As soon as it has been reeded, it must be divested of the mucilaginous material which it contains, by pouring water upon and repeatedly squeezing it. In this part of the process great care must be taken to prevent the fibres from getting entangled, as by that means great waste will be incurred.

M. Brealle, on the Continent, has suggested a mode, very different to any of these, for the purpose of steeping hemp, the advantages of which, it is asserted, have been fully proved by numerous trials. The process consists in heating water in a vessel, or vat, to the temperature of from 72 to 75 degrees of Reaumer, and dissolving in it a quantity of green soap, in the proportion of 1 to 48 of the hemp: the body of the water being about forty times the weight of the hemp. When this preparation is made, the hemp is thrown into it, and floats on the surface, and the vessel being immediately covered, the fire is put out. In this state the hemp is allowed to remain for two hours, at the expiration of which time it will be found to be fully steeped.

The principal superiority of this method, besides the great saving of time and expense, is said to consist in the hemp affording a greater proportion of tow. The value of the fuel, as well as the time employed in the process, should, however, be well considered in such cases. Besides these, it is said to promote the cultivation of the hemp crops, by the facility which it affords to the preparation, even in such situations as are not contiguous to rivers, streams, or ponds; it also obviates any ill consequences that might possibly ensue from the putrid effluvia of the atmosphere, and the corruption of the waters, induced by it, which last are well known to destroy the fish contained in them, as also to prove hurtful to the cattle that drink of them.