Herreshoff marine engine, 3 cylinder, triple expansion steam with exposed cranks, 350 HP; high, intermediate and low pressure cylinders in tandem; drip wick oil supply on eccentric straps, gravity feed oil supple and crank bearings steel piston and eccentric rods; relief valves on each cylinder; piston valves on steam parts; from commuter yacht NAVETTE, built 1916 by Herreshoff.