The burring-machine is represented in perspective and section in Figs. 1447, 1448. It has the usual feed-lattice a and rollers b, after which comes a beater or fan c. Underneath the worldng parts, a travelling lattice d is extended ; over its further extremity and in contact therewith, is a roller-brush e. The latter works in contact with the large cylinder, which is fitted with a series of steel plates, about 1 in. in width, set closely together, the front edges of which are armed with tine steel needle-like teeth, inserted ohliquely, so as to incline the points upward or forward in the direction of the revolution of the cylinder. These teeth do not project above the surface. Beneath the cylinder, are two small rollers g g', the first being clothed with bent card wire, and the second with strong hog-bristles. In close proximity to g', is the burr-roller h. Just above the burr-roller, two bars of iron i are extended across the face of the cylinder, the sides against the cylinder being concave, These are termed " ledger-blades." Acting in the space between these blades, is another hurr-roller j, and beneath this is a grid h, over it being another large roller I, carrying ribs and spikes, On the opposite side of the cylinder, is another large roller.brush m, whose function is to strip the wool from the cylinder, and discharge it into a box.
The process is as follows. The wool is fed by hand upon the lattice ct, which carries it between the rollers b, on delivery from which, it is struck downwards in tufts by the beater c, falling upon the interior lattice d, which carries it into contact with the revolving brush e; this conveys it to the cylinder f, the needle-pointed armour of which seizes the fibres, but forces the burrs into a prominent position, which subjects them to the strokes of the spiral blades of the burr-roller h, sometimes called the " knocker-off." The small card-roller g ships the wool from the brush roller e, which happens to escape being taken in the first instance by the large cylinder. This it delivers to the brush-roller g', which in turn gives it to the cylinder. When the wool has passed the burr-roller h, it is smoothed down by the concave faces of the bars I, after passing the first of whioh, the burrs that have escaped the first roller are caught by the second j, and struck off upon the grid k, where they become enbjeot to the action of the large rollez I, whose function is to beat them through the grid into a reeeptaele-provided for them. The wool now freed from its impurities is carried forward by the cylinder to the brush m, which revolving at a greater speed than the cylinder, clears it, and discharges the wool into a box.
The principle of the machine is to open and diaentangk the fibres of the wool so thoroughly as to loosen and throw the burrs into a position where they can easily be struck off and discharged by the rollers. The wool that adheres to the burrs can be recovered by the "extracting " process.
wool having got thus far is now ready for " blending." This is the mixing of different qualities together, in order to produce the required result. Where only one kind of wool is used in the prooess, it is simply spread in layers, and freely sprinkled with oil, when it is con sidered desirable to oil at this point. " Blends," however, are often made up containing more or less of other fibres than wools strictly so-c,alled. These are analogous animal hairs, shoddies, mungoes, " extracts," cotton, and silk waste. Of whatever the blend is composed, care should be taken to ensure that it shall be so thoroughly mixed that, in the succeeding processes, the incor poration of one fibre with the other shall be so perfect that all distinction between them shall be lost. If this is not accomplislied, the yarn will exhibit inequalities of draft, owing to the essentially different nature of the fibres, showing a rnass of cotton or other flbre at one place, and wool almost alone at another. In the dyeing and finishing processes, these defects come more strongly into view, after having at each stage proved unsatisfactory in working, and diminished the production. When the blend is composed of both animal and vegetable fibres, this care is doubly necessary, otherwise each fibre is likely to assert the individuality of its nature, and to separate from that with which it was required to blend. To ensure the desired results from the mixtures of fibres differing so essentially as do those of animal and vegetable origin, the amalgamation must be perfect.
In deciding upon the component parts of a blend, regard must be had to the fact that these different fibres do not all require a similar amount of carding, and that an incongruous mixture in this respect will often prevent the attainment of satisfactory results, even when otherwise the most perfect' care has been displayed. When two classes of material axe required to be mixed, they should harmonize in this respect as much as possible, whioh will give a chance of obtaining, if not of securing, the production of approximately perfect yarn. Another point to which attention ought to be paid is the fineness to which it is intended to spin the yaro. The capability of the separate fibrous materials of being drawn to this length must be kept in view, and harmony as nearly as possible be established, otherwise the capability of the best portion will be lost in that of the inferior ; or if the former is utilized, the lower quality will be thrown out as waste, and the result be costly and unsatisfactory. The end to be sought is to obtain the greatest possible percentage of yarn from the blend, at the least expense in labour ;,this cannot be done unless regard is had to these points. It is not true economy to overwork a low material, nor to underwork a good one. One fault is equally as bad as the other, though the errors may be on the opposite sides of the line of rectitude.