Jute fabrics are described by the number of " porters " and width in inches, the length being according to requirement. As an illustration, take say a "16-porter 40-in. Hessian, of 18 "shots " or picks per inch and 100 yd. hi length. The porter is the standard in jute manufacture by which the fineness of the " comb" (or set of heddles) and the reed are determined, and consequently the number of threads in the warp to make any given description of cloth. The porter is composed of 40 heddles, each peddle containing one thread, and 20 splits or dents of the reed, two threads going between each two dents. When one thread alone is used, the reed is as fine again. The number of porters in 37 in. of the reed indicates the fineness of the cloth. In the case supposed, it occurs 16 times, and so gives its denomination to the web. The texture of a jute fabric is, however, considerably modified in the finishing process to which it is subjected. This consists of heavy calenderiog, by which the length of the piece is increased at the expense of its width, and by means of which it may happen that the latter is so much contracted that, though woven as a "16-porter," it could only be accurately described by calling it an 18-porter fabric.
When the particulars of a cloth which it is intended to make are found, the necessary instruc tions are given to the warper. On 37 in., 2 in. are allowed for shrinkage in width, and 10 percent. for what is taken up in the length owing to the warp threads being deflected from a straight line by the insertion of the weft threads. This amount is not invariable, being-larger when the weft is coarse or heavy, and less when very fine.
Warping.—In establishments in which both spinning and weaving are carried on, the bobbins from the spinning-frame are often taken directly to the warper, and the cost of winding is thereby avoided. The bobbins are placed in a " back " or creel, and sometimes, when the fabric is very narrow, and the creel will contain a sufficient number of threads, these are run direct upon the weavers' beam, if it is intended to be used in the green state. When the warp requires a large number of threads, it is divided into four parts, one quarter being warped at a time, the four parts next being run upon the weavers' beam. This process is generally regarded as the most expedi tious and economical in making wide warps, as the small number of threads enables the warper to give them perfect attention, and, at the same time, permits the speed to be considerably increased. The warping-mill employed in the jute trade is the common vertical reel mill, composed of an upright beam revolving upon two iron pivots, one at each end. Into this beam are inserted three rows of arms : one each at the top, centre, and bottom. Vertical bars of wood are fixed upon the extremities of these arms, and the whole composes the reel. At the bottom of the central beam, is a pulley, around which passes the driving-band from a larger pulley outside the reel, whereby it is driven. Owing to the comparatively short length of jute warps, and the frequent stoppages that
occur in making them, it is customary to use manual power instead of steam, though the latter may be at hand. The warping-mill is therefore worked by means of the hand and foot of the attendant. The yarn from the banks or creel, being passed through two reeds, is attached to and wound spirally upon the reel, the length of the warp depending upon the number of turns of the reel before its action is reversed. The breadth is decided by the number of threads in the bank, and the number of " bouts," as a complete traverse of the winding process over the reel is termed. When the warp is completed, before it is " doffed," or removed from the mill, a " lease " is taken, which means that the threads have to be alternately elevated and depressed, to admit of the insertion of a transverse thread, to facilitate a subsequent process. In order to permit this to be done with facility, the two small reeds employed to conduct the threads from the bank of bobbins to the reel are utilized. The reed nearest the bank is constructed in the usual open way, but the second has every alternate split stopped with solder at about 1 in. from its rim, by which means the threads are instantly separated as desired. The doffing constitutes a chain, warp, or section' of a warp, as the case may be.
Beaming.—The next process is " beaming,' or winding the warp upon the loom-beam. The sections of the warp are placed side by side, and the threads from each are passed in a larger or smaller number through the dents or splits of a coarse reed, termed an " evener " or " wraithe," by means of which, when the machine is started, the yarn is wound evenly upon the beam, as guided. This evener contains 72 pins in 37 in., and sometimes has a loose top which is removed in order to insert the threads between the pine, and replaced to retain them in position for the winding process. The number of threads put into the apaeea between the pins are termed " pinfula." Drawing-in.—After beaming, the next process is to draw the warp threads into the eamb and the reed. The eyelets of the heddles are composed of wire rings. The " drawing-in " of the warp is a very simple process, accomplished by means of a hook being put through the reed and heddle rings, which, having the warp threads put over it by a child assistant of the drawer-in, is with drawn, bringing each thread with it. When all have been thus drawn in, the warp is ready for the loom. This process only takes place when a camb is new and has to be used for the first time. After the first warp has been woven to near the end, it is cut so as to leave a sufficient length behind the heddles, to which the succeeding warp can be tied.