In making the flat braid, when the individual rubber threads pass through the separate holes on the outer part of the bed plate of the machine, they all gather to one common center after they are through. This causes the rubber threads, when they are at a very high tension, to draw at a very acute angle at the edge of the hole, which necessitates running them at a lower tension than is desirable for economy. It also introduces a liability to break under the strain. In some mills this is cared for by passing each thread over a small case hardened steel roller, thus avoiding the friction at the edge of the hole. SIZES OF CORDS The sizes of cords are determined by the Birmingham wire gauge as follows (Diameters in decimal parts of an inch): Size 1 .300 Size 2 .284 Size 3 .259 Size 4 .238 Size 5 .220 Size 6 .203 Size 7 .180 Size 8 .165 In sizing or measuring the cord, it is passed easily into the gauge, so that it hugs the sides without crowding. Any cords made heavier than a No. 1 are designated by fractions of one inch in eighths. It becomes necessary in making heavy round cords, such as are used by athletes and in the manufacture of airplanes, to have a very durable covering over the strands of rubber. Such a covering is put on by using double deck machines, where above the regular machine there is another bed plate having a second set of carriers which travel around the braided fabric coming up from the lower deck. In such cases the inner covering is generally a cheap coarse material, while the upper deck of carriers braid the outer covering around it, which is of a higher grade material, often a highly glazed polished thread. Machines are made of a variable number of carriers to suit goods of different character that are required. Provision is made to carry the rubber beam in hanging brackets underneath the machine, which are of sufficient strength and firmness to carry the maximum weight necessary for governing the rubber tension. Above the machine there is a gear-driven take-up shaft, on which are tension rolls to govern the feed of the goods when braiding. The speed of these rolls can be regulated by change gears of various sizes. The goods are then fed on a belt-driven spool. On the very heavy goods it is necessary to pass them through other press rolls to prevent any slipping back when feeding from the braiders. FANCY BRAIDED CORDS