Among the sewing machines for doing special kinds of work or work on special materials are the shoe and leather sewing machines, the carpet sewing machine, and the button-hole machine. By far the most important of these, in practical results attained, is the shoe-sewing machine. The McKay machine was the result of three years of patient labor and of an expenditure of over $130,000 before practical results were at tained. In using this machine the inner sole is first placed on the last and then the upper is lasted and fastened to the inner sole. The outer sole is then placed above the lower sole, to which it is tacked, and the shoe 'is placed OD a horn or rotary support which brings the shoe up to the needle of the machine. A waxed thread wound on a spool is contained on a spool within the horn and is carried up to the whirl or small ring at its upper end, where there is an opening for the needle, which comes down from above, piercing the sole. The waxed thread, which is kept soft by the heat of a lamp. is caught by a barb or hook on the needle as it descends through the hole, and is pulled back through the sole on its upward passage. This machine attended by a single operator can sew 900 pairs of shoes in a day of ten hours, while a usual rate by an aver age workman is from 500 to 600 pairs in a simi lar time. It was used extensively both in the United States and in Europe, hut it possessed the disadvantage that the shoes, though strong and comfortable when first made, could not be resoled except by pegging or nailing, and pos sessed in addition soles stiff and lacking in flexibility, In the Goodyear welt machine, for which patents were granted in 1871 and 1875, a welt was sewed to an upper and this welt in turn was fastened by an external row of stitches to the sole. Shoes made in this
way were much more flexible and could be half soled by the shoemaker by the ordinary process of hand sewing. This machine at once found application to the manufacture of fine boots and shoes, and on it at the present time are made nearly all of the finer grades of men's shoes.
The first machine for sewing leather and other heavy materials was patented by J. J. Greenough in 1842, but did not come into extended use. The following year a similar machine was patented by George II. Corliss, the inventor of the Corliss engine. It had two needles with eyes near their points, which worked horizontally through holes previously punctured by awls. The movements were derived from cams on a revolving shaft and the feed was S automatic. Leather-sewing chines are now used in all branches of the leather industry, including the sewing of the uppers of shoes and the different kinds of stitching re quired in the manufacture of gloves.
A button-hole machine was first patented by Humphrey in 1862, but the Reece button-hole machine, patented nearly twenty years later, first brought the art of making button-holes by ma chinery to its present state of perfection. There are several styles of these machines now on the market and a button-hole attachment is sold with ordinary sewing machines.
An invention patented in 1894 is a machine for sewing the breadths of carpeting. It differs from other sewing machines in that it, and not the material, moves along as the process of sew ing advances.
In the manufacture of sewing machines Amer ica leads the world. Not only are great numbers of machines exported, but several of the leading manufacturers have branch factories in Europe.