12,136. Stempel, W. May 22. Chucks; indexing.-A dividing-device for use in chucks, work-holders, &c. consists of a concentric ring t carrying a vernier scale z and a water-level w rotatably mounted on the body of the chuck but adapted to be fitted thereto by a screw k, and another scale s fixed to the chuck or formed on a concentric ring which can be fixed to the chuck by a screw x. In operation, to rotate the work, the ring t is rotated on the chuck to the required division on the scale s, and is then fixed to the chuck and the whole rotated back until the level is horizontal again. The jaws of the chuck are operated by a scroll on a bevel-wheel c rotated by a bevel-pinion e.