10 W. H. WARREN, 
overload and underload the economy is relatively greater. 
Again, the steam turbine maintains its economical use of 
steam for a much longer period than the reciprocating 
engine, as it is not affected by cylinder wear. 
2. The turbine is capable of utilizing a higher vacuum . 
than the reciprocating engine, by expanding practically 
down to the condenser pressure. 
3. There is no necessity for internal lubrication as in the 
reciprocating engine, and consequently oil does not find its 
way into the condensers and boilers when turbines are used, 
thus obviating serious difficulties. 
4. The construction of the turbine admits of the use of 
superheated steam without disadvantages such as occur in 
its use in reciprocating engines. 
o. There is a considerable saving in oil and much less 
wear and tear than in reciprocating engines. 
6. There is considerable economy in space. 
7. The turbine is a perfectly balanced machine, having 
a uniform torque, and there are consequently no disturbing 
effects due to unbalanced parts as in the reciprocating 
engine; so that it does not require heavy foundations. 
8. The turbine is especially adapted to high speed vessels, 
such as torpedo boat destroyers, as there are practically 
no vibrations such as those which occur in reciprocating 
engines. 
9. Steam turbines of the Parsons’ type are capable of 
driving alternators which will work synchronously with 
each other, or with properly designed alternators driven 
by reciprocating engines. 
Steam turbines are capable of driving centrifugal pumps 
of the ordinary or reversed turbine class. A Parsons’ 
steam turbine coupled to three similar centrifugal pumps 
working in series, and mounted on the same bed plate has 
