In spinning worsted by machinery, a sliver of wool is laid upon the drawing-frame, from whence it is conducted through several pairs of rollers, of which the operation of the first and last are the essential ones, the intermediate rollers moving with equal velocities, and serving merely to conduct the skin, which is received into a cylindrical can; three such skins being passed through another drawing-frame, and stretched in their progress, become fitted for roving, - the last step in the preparatory process. The spinning, which is the concluding process, is effected by means of two pair of rollers moving with equal velocities, and intermediate auxiliaries.

In manufacturing short wool into cloth, it is first soaked in urine, and frequently rinsed in clean water, which adapts it to the next operation, - that of carding. The carding engine for fine short wool is constructed with one main cylinder, having in lieu of the top cards used in jenny-spinning, numerous small rollers, lying and rolling upon its upper surface; it is used in place of a breaker engine, and is called a scribbler. The wool is delivered from a main cylinder to a doffer, and, being combed or doffed, is carried to another engine called the carder, which perfects the carding, and delivers it off, by means of grooved mahogany rollers, in a row or rowan, as in jenny-spinning. If the wool is of a coarse description, such as is formed into yarn, for the manufacture of coarse cloths, more carding is required.

The scribble engine has three distinct parts or cylinders in one frame. The first part consists of the first main cylinder with its top rollers, and is called the breast; this delivers the wool to the second main cylinder, which with its top rollers is called the first part; this delivers it up to a small intervening cylinder called the tween doffer, which carries it to the third main cylinder, which, with its top rollers, is called the second part; from hence it goes to the last doffer cylinder, from which it is combed by a doffing-plate, and finally carried by hand to a carding engine; by which the wool is formed into separate and smooth rolls of twenty-eight inches long, and half an inch thick, which are immediately taken by boys, and attached to the spindles of the roving or slubbing machine. This machine draws out the wool into large and slightly-twisted threads, and winds it into balls ready for spinning. By the spinning-jenny the threads are twisted, and drawn to a proper degree of size and strength, and are then reeled into skeins and prepared for the loom. The stronger sort intended for the woof is wound on spools, or quills, which are tubes of such a size and shape as to be easily placed in the hollow of a shuttle.

That designed for the warp is wound on large wooden bobbins, from which it is by the warp-ing-bar conveniently arranged for the chain or warp of the piece.

A patent was taken out a few years since, by Mr. Hadden, for improvements in preparing wool, and also for roving and spinning it in a heated state. The patentee observes, that various methods may be adopted for supplying heat to wool, during all or either of the three processes of preparing, roving, and spinning. The method which Mr. Hadden has adopted is the introduction of cast-iron heaters into the retaining rollers used for these processes, observing that he always uses three rollers or cylinders together, and by leading the wool over half the circumference of the upper two rollers, charged within with the heaters above mentioned, he thoroughly warms the wool, without retarding the progress of the other presses.

The mode of applying the heaters is by making the retaining cylinders hollow, and by introducing a cylindrical heater into each retaining cylinder. These heaters are made exactly to fit the interior of the retaining cylinders, the axes of which pass through a channel for that purpose in the middle of the heater. It is to be observed that the heaters may be put within the driving cylinders with equal effect.

The qualities which distinguish woollen cloths from all other manufactures, and renders them particularly suitable for northern climates, are the compactness and density they acquire from the operation of fulling. The cloth is sprinkled over with a liquor prepared from oil of olive soap dissolved in hot water, and then laid in the mill-trough, where it is pounded with heavy wooden hammers. By this process a cloth 40 yards long, and 100 inches wide, is reduced to 30 yards long, and 60 inches wide. During the operation the cloth is taken from the trough, the wrinkles smoothened, and more soap added. The property of becoming thicker by compression is peculiar to woollen cloths. It is said that the fibres of the wool are thickly set with jagged protuberances, which it is supposed catch hold of each other when pressed together, and thus become inextricably united, so that the cloth when cut does not unravel like other cloth. After milling, the cloth is scoured with a preparation of fuller's earth and bullock's galls, till perfectly free from soap, and then taken to the cloth-worker to be dressed.

This operation is performed by first drawing out and placing in one direction, by means of wire cards and teazles, all the fibres of wool that can be brought to the surface, and then shearing them as close as may be practicable without laying the threads of the cloth bare. The instruments employed in this process were formerly worked by hand; but this operation is now performed by machinery, in a very superior manner to any manual efforts, and at a much les3 expense. When this process is completed, the cloth is taken to the rack, where it is strained so as to bring it to an even breadth throughout its length, and it is then sheared again, to render it perfectly level and uniform. All the little bits of straw or lint that may adhere to it are now picked out, and any holes that may be discovered carefully fine-drawn. The cloth is next laid in a press with a sheet of glazed paper between every fold; these are covered by thin boards, and hot iron plates laid thereon, by which a gloss is communicated to the cloth.