This dynamometer is designed for testing electric motors up to 100 HP at up to 3600 RPM.  It is branded as "Inductor", and made by the Frank Wells Company, model OD-1222.  The torque measurement system no longer works, but it can still fully load motors for testing them at load. 

Includes a variety of mounting bases and lovejoy couplings for different motor frame sizes, from 180 up to 400 series frames.