Fig 6.

Weaving 707

In a lecture delivered by Dr. Birkbeck, at the London Mechanics' Institution, on the subject of weaving, this loom was publicly worked, when it was found to weave at the rate of a yard and a quarter per hour of gros de Naples.

Some successful attempts have recently been made to produce a figured or rather variegated pattern in silks by plain weaving. It is effected by composing the weft or woof of two different coloured threads twisted together; which may be of silk, of silk and worsted, or of linen, cotton, and silk, variously combined. The more the colours are contrasted, the more brilliant, of course, is the effect. Long specks or spots are produced by twisting the threads very slightly, and short or minute ones by a hard twist. The warp of the fabric, as well as the shoot are composed of a similar or different arrangement of threads, and thus by slight variations, a great diversity of pretty patterns may be obtained.

A patent was taken out in 1833 by Mr. W. Graham of Glasgow, for "a self-acting temple to be used in the operation of weaving by power or hand looms," for the purpose of keeping the fabric at the width the reed leaves it. The invention consists in an apparatus affixed near each end of the breast-beam, which, being acted on by the swinging of the lay in beating up the weft, are caused to open and shut, and, by means of these apparatuses, the cloth is held to the width at which the reed leaves it after beating up the weft.

Weaving 708

The above is a perspective view of the apparatus, a, is a plate which is affixed to the breast-beam of the loom at the slot at b, by means of a screw-bolt passing through the breast-beam; and where different widths of fabric are woven in the same loom, the temples must be so constructed as to allow of being brought nearer to, or farther from each other, by means of the slots formed in the plate a. On to the plate a is fixed, by means of a screw, another plate c, having a projection d, which is turned down at right angles at e, the object of which will be hereafter described. The outer end of the plate c is turned over, so as to produce a parallel plate f, having a space between them; g is a spring affixed to the plate c, by rivetting or otherwise, and on the face of this spring is formed teeth or grooves, cut in a line with the direction of the cloth, these teeth or grooves being intended to hold the cloth when the spring is pressing upwards against the platef; i is a lever, which has its fulcrum at j on the plate a; and at one end of the lever i is formed a projecting wedge k, which is pressed between the upper plate f and the spring g every time the lay beats up the welt, by the lay coming in contact with the other end b of the lever i, this and /, being turned down, as shown in the drawing, for that purpose.

There is to be one of these apparatuses placed near the breast-beam, that is, in such a position that they shall just embrace the outer edges or selvages of the fabric, between the platefand the spring g, and they are so placed as to take hold of the fabric as near as possible to the point at which the reed strikes up the weft; but the reed is prevented being injured by the bottom of the lay coming in contact with the parts e, which stops the lay from approaching too near to the temples at the beating up the weft; and at the time the Jay has nearly finished its stroke it comes against the part l of the lever i, which drives the wedges k between the plates f and the springs g, and causes them to separate to permit the fabric being drawn through them; but immediately on the receding of the lay, after having beaten up the weft, the springs g will press up against the platesf, and retain the cloth between them, the wedges k being forced out by the pressing up of the springs, and by this means the fabric will be kept to the width at which the reed leaves it.