It is desirable, in the process of roughing or raising the pile upon woollen cloth, that the action of the teazles should be made to deviate from straight lines on the surface of the cloth. The patented improvement of Mr. Oldland, dated July 1830, tbr this object, consists in a horizontal revolving teazle frame. furnished On its under side with teazles, wire-cards, brushes, or other materials used in dressing or raising the pile of the cloth. The revolving teazles are put in motion by a band fixed to the revolving spindle ; and as the cloth is brought under the teazles by conducting rollers of the usual construction, it is pressed up against the teazles by a supporter covered with some elastic only on that side of the centre of motion of the revolving teazle which moves from the middle towards the selvage of the cloth, the teazle frame reaching only halfway across it; and one being placed on each side, moving in different directions, the pile will be raised in all cases from the centre towards both selvages of the piece of sloth, though from the nature of toe action of this machine it is evident that its operation on the cloth can in no case be rectilineal, and that by the end motion of the cloth the lines of action will be continuallycressing each other at very acute angles. In the same year another patent was taken by Mr. Paps, for the same object, in which the principle and operation are the same, though the detail, vary a little. A third patent for the same object was granted on the same day as the last mentioned, to Mr. Ferrabee, who raises the pile in a different direction. namely, from the middle sloping to the sides; for thishe employe tw9 series of teazles ; each series isattached to an endless 'is whichround two cylinders by which it is put in motion. Two of the cylinders which support and give motion to the teazle chains are placed with their axes extendingalong the middle of the piece of cloth to be operated upon, and the other two li are placed near the selvages of the cloth, with their axes parallel thereto. Each pair of cylinders is made to turn in a direction to raise the pile of the cloth from the middle towards the selvages, at right angles to them when the cloth is at rest ; but when an end motion is given to the cloth, which is effected by means of two cylinders placed at right angles to the teazle cylinders, the pile is raised in an angular direction, sloping from the middle towards the selvages. The angle of the work may be varied at pleasure, by varying the relative speeds of the different sets of cylinders.
The processes employed in dyeing woollen cloth differ considerably from those used in silk and cotton. The oil is first removed by the operations of the fulling mill, where it is beaten with large beetles in troughs of water, mixed with fuller's earth ; and when thoroughly cleansed it is ready for dyeing. The only colours used in dyeing wool blue, are woad and indigo, which are both colours, that is, they are permanent without requiring a mordant. Queer mere recommends the following mode of preparing a blue vat :—Into a of about seven and a half feet deep, and five and a half broad, are throw. tar balls of woad, weighing together about 400 lbs., first breaking them ; pounds of weld are boiled in a copper for three hours, in a sufficent quantity al water to fill the vat; when this decoction is made, twenty pounds of madder and a basket full of bran are added, and it is boiled half an hour longer. ThIi
bath is cooled with twenty buckets of water • and, after it is settled, the weld is taken out, and it is poured into the vat ; all the time it is running in, and for a quarter of an hour after, it is to be stirred with a rake. The vat is then covered up very hot, and left to stand six hours, when it is raked again for half an hour, and this operation is repeated every three hours. When blue veins appear on the surface of the vat, eight or nine pounds of quick lime are thrown in. Immediately after the lime, or along with it, the indigo is put into the vat, being first ground fine in a mill, with the least possible of water (it is now usually ground dry.) When it is diluted to a semifluid consistence, it is drawn of at the lower part of the mill, and thrown thus into the vat. The quantity of indigo depends upon the shade of colour required. From ten to thirty pounds *lust therefore be put to the vat now described, according to the occasion.
If, on striking the vat with the rake, a fine blue scum arises, it is fit for use, after being stirred twice with the rake in six hours, to mix the ingredients. Great care should be taken not to expose the vat to the air, except when stirring it As soon as that operation is over, the vat is covered with a wooden lid, ea which are spread thick cloths, to retain the heat as much as possible. Not this care, the heat is so much diminished at the end of eight or ten days, that the liquor must' be re-heated, by pouring the greater part of it into a copper over a large fire ; when it is hot enough, it is returned into the vat, and covered as before.
This vat is liable to two inconveniences : first, it runs sometimes into the putrefactive fermentation, which is known ,by the fetid odour it exhales, and by the reddish colour it assumes. This accident is remedied by adding more lime. The vat is then raked : after two hours, lime is put in, the raking per again. and these operations are repeated till the vat is recovered; secondly, if too much lime is added, the necessary fermentation is retarded; this is re medied by patting in more bran or madder, or a basket or two of fresh woad.
When cloth is to be dyed, the vat is raked two hours before the operation ; and to prevent it from coming in contact with the sediment, which would cause inequalities in the colour, a kind of lattice of large cords, called a cross, is intro duced ; when unmanufactured wool is to be dyed, a net with small meshes is placed over this. The wool or cloth, being thoroughly wetted with lukewarm water, is pressed out, and dipped into the vat, where it is moved about a longer or shorter time, according as the colour is intended to be more or less deep, taking it out occasionally to expose it to the air, the action of which is necessary to change the green colour, given the stuff by the bath, to a blue. Woollen and cloth dyed in this manner ought to be carefully washed, to carry off the loose colouring matter; and, when they are of a deep hue, soap should be used, as it will only cleanse and not injure the colour. The more perfectly the wool has been scoured, the better it will receive the dye.