Machines of Class 11 have a cylinder bed and a drop feed, and are especially designed for stitching heavy tubular shaped articles in cloth or leather. They are used in the manufacture of mail bags, coal bags, ore bags, military boots and a great variety of similar articles. Some of the machines of Class 11 are intended for making grommet holes and overseaming or zig-zag stitching in heavy fabrics. Machine 11-37 is used for stitching the legs of fine quality boots and other tubular shaped articles made of light or medium )veight leather. This machine feeds the work up the cylinder. The maximum lift of the presser feet is inch and stitches varying in length up to % inch can be readily made. The “SINGER” Driving Attachment is regularly fitted to this machine.