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 11-29 is used for stitching tents, tarpaulins, wagon covers and heavy tubular shaped articles in canvas. This machine is regularly fitted with alternating pressers, flexible shuttle race, foot lifter, 23^ inch cylinder shuttle, two speed balance wheel and feeds the work across the cylinder. The machine can be readily adjusted to make stitches varying in length up to y* inch, as desired.