Page:Popular Science Monthly Volume 41.djvu/522

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THE POPULAR SCIENCE MONTHLY.

The first decisive step in sewing the sole and upper together was taken by Lyman R. Blake in 1858, his machine being perfected as the McKay sole-sewing machine. The machine, as described by Blake in his application for an English patent, "is a chain-stitch sewing machine. The hooked needle works through a rest or supporting surface of the upper part of a long, curved arm which projects upward from the table and the machine. This

PSM V41 D522 Leather cutting room.jpg
Fig. 9.—The Cutting Room.

arm should have such a form as to be capable of entering a shoe so as to carry the rest into the toe part as well as any other part of the interior of it. It carries at its front end and directly under the rest a looper, which is supported within the end of the arm so as to be capable of rotating or partially rotating round the needle, while the needle may extend into and through the eye of the looper, such eye being placed in the path of the needle. The thread is led from a bobbin by suitable guides along the curved arm, thence through a tension spring applied to the arm, and thence upward through the notch of the looper. The feed-wheel, by which the shoe is moved along the curved arm during the process of sewing, is supported by a slider extending downward from the block and applied thereto so as to be capable of sliding up and down therein. The shoe is placed on the arm with the sole upward." In less technical language, the machine consists of a combination of wheels so arranged as to drive an awl-like needle through several thicknesses of heavy leather, and feed a waxed thread in any direction. The shoe itself rests upon the end of the