27,421. Gregson, G. F., and Gregson, J. J. Dec. 12. Yarns, dressing. -The pressure upon the usual friction plates B for driving the warp p beam in a dressing-machine is obtained from a weighted lever K, which is connected by a link O with a bell-crank lever P, carrying at one end a stud S which presses upon a lever C provided wit h antifriction bowls G engaging with the plate B. The pressure is regulated by moving the weight I along the lever K, which may be supported by a prop L in the raised position when it is desired to remove the beam &c.