In designing webs of this character, calculations have to be made from the web after it is woven and finished, otherwise the design may be out of the desired proportion. A web may have 60 picks per inch on the breast plate while weaving, but when contraction has taken place after going through the press, it may have shrunk as much as 50 per cent. The steaming and finishing process may further contract it another 10 per cent. which might make the picks about 100 per inch. Of these only one-half appear on the face and the other half on the back. Therefore 50 picks per inch will be the proportion in which the design should be made, and paper scaled according must be used. CROSS SHOT WEAVING We have so far confined our remarks to webs made on single shuttle looms. Turning our attention to the use of more than one bank of shuttles we would first make note of what is known as the cross shot. This is a form of weaving which largely increases the output and has in it the further element of economy, inasmuch as by this method the rubber warp can be worked at a much higher tension than by the single shuttle method. In the construction of single shuttle webs, the rubber harness rises and falls at each passage of the shuttle across the shed. This movement creates a friction on the rubber thread at the harness eye and an added friction at the front reed by its passing up and down in the dent. Friction is still further increased by the backward and forward movement of the lay, which makes two such passages to one made by the cross shot. In the cross shot method, the rubber remains stationary, with no upward and downward motion, which enables the rubber thread to be stretched out to its extreme limit while weaving, with little danger of chafing or breaking. Over and under this stationary rubber are two distinct sheds, one making the upper and the other the lower cloth. These two fabrics are stitched together by the binder warp, which travels up and down through both of these sheds. In order to keep all the warp threads uniformly tight while shedding, it is necessary to run these under separate back rolls, fixed at different heights, properly centering the upper and lower sheds with the harness and breast beams. POSITION OF ROLLS Fig. 4 will explain the position of the various rolls in relation to the breast beam. It will also show the peculiar formation of the shuttles used for this type of weaving, both pointing to one common center, made necessary by the character of the two sheds. The bow of the upper shuttle must be tipped downwards, and the lower bank must be tipped upwards, so as to reduce the friction of the shuttles all possible when they are passing through the sheds.