The employment of wool in the manufacture of broadcloth and flannel was, a few years ago, almost the entire business of the woollen factories. The novel uses to which wool is now applied, and the almost innumerable varieties of articles of clothing which are produced from long wool and short wool--from combinations of alpaca wool and coarse wool, of wool with cotton, of wool with silk--together with the introduction of brilliant dyes and tasteful designs, formerly unknown--have established vast seats of manufacture which are almost peculiar to our country, and have converted, in a few years, humble villages into great cities. The finest Paisley shawls rival the elaborate handicraft of Hindustan; and, what is of more importance, the humblest female may purchase a tasteful article of dress at a price which a few years ago would have been thought fabulous. The wonderful variety of patterns which we see in these and other productions of modern skill are effected by the Jacquard apparatus, in which the pattern depends upon the disposition of holes pierced in separate bits of pasteboard. In common weaving, the weft threads pass alternately under and over the entire warp threads, which are lifted up to allow the weft in the shuttle to traverse from one side to the other. The Jacquard apparatus determines, by the number and arrangement of the holes in the cards, which of the separate warp threads shall be so lifted; for at every throw of the shuttle the blank part of each card moves a series of levers which raise certain warp threads; while other levers, passing into the holes in the card, do not affect the other warp threads. In this way, patterns of the greatest complexity are woven in cotton, and worsted, and silk; so that even a minute work of art, such as a portrait or a landscape, may be produced from the loom. Every pattern requires a separate set of cards. We do not expect this brief notice to be readily understood. Those who would comprehend the extent of ingenuity involved in the principle of this invention, and the beautiful results of which it is capable, should witness its operation in a Halifax power-loom. In a bobbin-net machine the cards are connected with a revolving pentagonal bar, each side of which is pierced with holes, corresponding with the pins or levers above. When a card comes over the topmost side of the pentagon the levers drop; but those pins only which enter through the holes in the card affect the pattern which is being worked. Any one who views this complicated arrangement in a Nottingham lace-machine, requires no small amount of attention to comprehend its mysterious movements; and when the connection is perceived between that chain of dropping cards, and the flower that is being worked in the lace, a vague sense of the manifold power of invention comes over the mind--we had almost said an awful sense. [Illustration: Jacquard cards.] * * * * *