3i6 MODERN PAPER-MAKING As the weight of the web increases, the paper is pressed harder to the cylinders and wound tighter, which is the reverse of the friction type, where the pull of the friction has less effect as the web increases in diameter. The weight of the levers is so applied that the web can be partly supported to ensure regular pressure from the start to the finish of the reel. In the drum winder all the slit webs are wound on one spindle, strawboard centres of the requisite width [Messrs. Masson, Scott and Co., Ltd. FIG. 134.—VOITH TYPE HIGH-SPEED SLITTING AND REWINDING MACHINE being put on the bar and kept tight and in position by an expanding device. The paper is wound by the action of two cylinders travelling close together in the same direction, the webs being in contact with both. The cylinders are sometimes spiralled on the surface, outwards from the centres, to reduce the chances of creasing. If only one cylinder is used, the web is pressed against it by means of levers at the spindle ends, or else it runs directly on top of it. When it is necessary to reel two webs of different yardage a four-drum winder is used. By this means two webs of different lengths may be run off at the same time from the same reel.