and as it descends through the sole the whirl lays the thread in this hook, and as the needle rises it draws the thread through the soles and forms a chain stitch in the external channel of the outer sole. As the sewing proceeds, the horn is rotated so as to bring every part of the margin of the sole under the needle. With this machine a single operator has been able to sew nine hundred pairs of shoes in a day of ten hours, and five hundred to six hundred pairs is only an average workman’s output. It is said that up to 1877 there were 350,000,000 pairs of shoes made on this machine in the United States, and probably an equal or greater number in Europe. Shoes made on this machine were strongly made and comfortable, but they could not be resoled by a shoemaker, except by pegging or nailing, and the soles were furthermore somewhat stiff and lacking in flexibility. To meet these difficulties, a new machine known as the “Goodyear Welt Machine,” was patented in 1871 and 1875, and brought out a little later. This sewed a welt to an upper, which welt in a subsequent operation was sewed by an external row of stitches to the sole. This gave much greater flexibility, and the further advantage of enabling a shoemaker to half sole the shoe by the old method of hand sewing. This advanced the art of shoemaking in the finer varieties of shoes, and to-day nearly all men’s fine shoes are made in this way. The introduction of the sewing machine into the shoe industry made a new era in foot wear, and it is said that no nation on earth is so well and cheaply shod as the people of the United States. [Illustration: FIG. 147.--MCKAY SHOE SEWING MACHINE.]