In the steam engine the backward and forward motion of the piston-rod is changed into one of turning by means
of the connecting rod. A great deal of friction has to be overcome at the joints which connect the parts which
effect this change. Thus a great loss of energy is incurred.
In the steam turbine, the steam causes the parts upon which it acts to rotate. There is no to-and-
fro motion to be converted, so that the whole force is used as driving power.
