These operations being finished, the cords or mounting which move the ped dles are applied; the reed is placed in the lay, or batten, and the warp is divided in to small portions, which are tied to a shaft connected by cords to the cloth beam.
When the weaver has finished these two operations of beaming and drawing, he proceeds to dress his warp. And here it should be remarked, that the operation of dressing applies principally to cotton. The same practice, when used upon silk, has a very destructive tendency ; which is that of injuring the colours of the silk ; and when used, as it sometimes very im properly is, by weavers of white satin, the injury done to the work is irreparable. In cotton, the operation of dressing is indis pensable; in silk, this is by no means the case.
Dressing is justly esteemed of the first importance,, in the art of weaving warps spun from flax or cotton ; for it is impossi ble to produce work of a good quality, un less care be used in dressing the warp.
The use of dressing is, to give to yarn _ sufficient strength or tenacity, to enable it to bear the operation of weaving into cloth. It also, by laying smoothly all the ends of the fibres, which compose the raw mate rial from which the yarn is spun, tends both to diminish the friction during the process, and to render the cloth smooth, and glossy, when finished. The substance in common use for dressing, is simply a mucilage of vegetable matter boiled to a consistency in water. Wheat flour, and sometimes potatoes, are the substances, commonly employed. These answer sufficiently well in giving to the yarn both the smoothness and tenacity required; but the great objection to them is, that they are too easily and rapidly affected by the operation of the atmosphere. When dressed yarn is allowed to stand exposed to the air, for any considerable portion of time, before being woven into cloth, it al ways becomes hard, brittle, and compara tively inflexible. It is then tedious and trou blesome to weave, and the cloth is rough, wiry, and uneven. This effect is chiefly re marked in dry weather, when the weavers of fine cloth find it indispensably necessary to have their yarn wrought up, as speedily as possible, after being dressed. To counteract this inconveniency, herring or beef brine, and other saline substances, which have a tendency to attract moisture are sometimes mixed in small quantities with the dressing: but this has not proved completely and generally successful, pro bably, beause the proportions have not Leen sufficienly attended to, and because a superabundance of moisture is equally prejudical with a deficiency. Indeed, the variation of the moisture of the air is so great and so frequent, that it has hitherto been impossible to fix any universal rule for the quantity to be mixed.
It is stated as a fact, which will appear singular to weavers in this country, that in India the process of weaving, even their finest muslins, is conducted in the open air, and exposed to all the heat of the cli mate, which is intense. (See TIANUFAC
TURE of Cotton.) We know well that this would be impracticable with fine work in this country, even in an ordinary summer day. It is not known, in this country, what is the substance which the Indian weavers employ for dressing their warps. It certainly would prove of important be nefit to our manufactures were this investi gated in a satisfactory manner.
Neither does it appear that this subject, which is of much importance, has hither to attracted the attention of scientific men, or that it has been treated in an accurate or philosophical manner. It, however, opens a wide field for chemical investiga tion, and promises to prove equally useful to mankind, and lucrative to the person who may succeed in supplying the desi deratum.
When the warp, previously dressed, has been wrought up, as far as can be done conveniently, the weaver is obliged to suspend the operation of weaving, and to prepare a fresh quantity of warp. It is necessary to stop, when the dressed warp has approached within two or three inches of the back leaf of the heddles, that room may be allowed to join the old dressing to the new. The first operation, as in wool and silk, is to clear the warp, with the comb, from the lease rod to the yarn roll, or beam. The proof that this operation has been properly executed is, by bringing back the rods, successively, from their working situation to the roll. When this has been done, the two fads nearest to the heddles, are drawn out of the warp to one side, and the lease rod only remains. The next duty of the wea ver is to examine the yarn about to be dressed, and carefully to take away every knot, lump, or other obstruction, which might impede the progress of the work, or injure the fabric of the cloth. In silk warps no further dressing is necessary ; but in cotton warps the weaver proceeds to apply the substance used for dressing, which is rubbed gently, but completely, -nto the whole warp, by means of two brushes used in succession, one of which he holds in each hand. He then raises the lease rod, which in cotton weaving is a middle rod, on one edge to divide the warp, and sets the air in motion by mov ing a large fan, for the purpose of drying the warp which has been dressed. Fus tian weavers use a large red-hot iron for this purpose. It is proper in this stage of the operation, to draw one of the dress. ing brushes lightly over the warp at inter vals, in order to prevent any obstruction, which might arise by the threads, when agitated by the fan, cohering or sticking to each other, whilst in a wet state Whenever the warp is sufficiently dried a very small quantity of grease is brushed over it, the lease rod is again placed upon its flat side, and cautiously shifted for ward to the heddles. The other rods are then put again into their respective sheds, and the process is finished.