[W/K] :: Steam engine

  Steam engine \Steam" en"gine\ ([e^]n"j[i^]n).
     An engine moved by steam.
     [1913 Webster]
  
     Note: In its most common forms its essential parts are a
           piston, a cylinder, and a valve gear. The piston works
           in the cylinder, to which steam is admitted by the
           action of the valve gear, and communicates motion to
           the machinery to be actuated. Steam engines are thus
           classified: 1. According to the way the steam is used
           or applied, as condensing, noncondensing, compound,
           double-acting, single-acting, triple-expansion, etc. 2.
           According to the motion of the piston, as
           reciprocating, rotary, etc. 3. According to the motion
           imparted by the engine, as rotative and nonrotative. 4.
           According to the arrangement of the engine, as
           stationary, portable, and semiportable engines,
           horizontal and vertical engines, beam engine,
           oscillating engine, direct-acting and back-acting
           engines, etc. 5. According to their uses, as portable,
           marine, locomotive, pumping, blowing, winding, and
           stationary engines, the latter term referring to
           factory engines, etc., and not technically to pumping
           or blowing engines. Locomotive and portable engines are
           usually high-pressure, noncondensing, rotative, and
           direct-acting. Marine engines are high or low pressure,
           rotative, and generally condensing, double-acting, and
           compound. Paddle engines are generally beam,
           side-lever, oscillating, or direct-acting. Screw
           engines are generally direct-acting, back-acting, or
           oscillating. Stationary engines belong to various
           classes, but are generally rotative. A horizontal or
           inclined stationary steam engine is called a left-hand
           or a right-hand engine when the crank shaft and driving
           pulley are on the left-hand side, or the right-hand
           side, respectively, of the engine, to a person looking
           at them from the cylinder, and is said to run forward
           or backward when the crank traverses the upward half,
           or lower half, respectively, of its path, while the
           piston rod makes its stroke outward from the cylinder.
           A marine engine, or the engine of a locomotive, is said
           to run forward when its motion is such as would propel
           the vessel or the locomotive forward. Steam engines are
           further classified as double-cylinder, disk,
           semicylinder, trunk engines, etc. Machines, such as
           cranes, hammers, etc., of which the steam engine forms
           a part, are called steam cranes, steam hammers, etc.
           See Illustration in Appendix.
           [1913 Webster]
  
     Back-acting steam engine, or Back-action steam engine, a
        steam engine in which the motion is transmitted backward
        from the crosshead to a crank which is between the
        crosshead and the cylinder, or beyond the cylinder.
  
     Portable steam engine, a steam engine combined with, and
        attached to, a boiler which is mounted on wheels so as to
        admit of easy transportation; -- used for driving
        machinery in the field, as thrashing machines, draining
        pumps, etc.
  
     Semiportable steam engine, a steam engine combined with,
        and attached to, a steam boiler, but not mounted on
        wheels.
        [1913 Webster]

  steam engine
       n : external-combustion engine in which heat is used to raise
           steam which either turns a turbine or forces a piston to
           move up and down in a cylinder