Source : Webster's Revised Unabridged Dictionary (1913)

Torsion meter \Torsion meter\ (Mech.)
   An instrument for determining the torque on a shaft, and
   hence the horse power of an engine, esp. of a marine engine
   of high power, by measuring the amount of twist of a given
   length of the shaft. Called also {torsimeter}, {torsiometer},
   {torsometer}.