Synopsis.-The measurement of torque under unstable conditions under stable conditions, and to obtain a permanent record of these of speed is usually extremely difficult and inaccurate when a measurements. It has been particularly successful in recording dynamometer, prony brake, or similar torque measuring equipment speed-torque curves of motors during acceleration and it can also be is used. The device described in this paper was developed primarily applied very effectively to other fields. to obtain torque measurements under unstable conditions as well as