ITS  APPLICATION  ;  ITS  TEACHINGS  RESPECTING  THE  CONSTRUCTION  OF  THE  ENGINE
AND  ITS  IMPROVEMENT 457

Origin  of  all  Energy,  457;  the  Progress  of  Energy  through  Boiler  and  Engine,
458 ;  Conditions  of  Heat-Development  in  tbe  Boiler,  45S ;  the  Steam  in  the  En-
pine.  458;  the  Expansion  of  Steam,  459;  Conditions  of  Heat-Utilization,  460;
Loss  of  Power  in  the  Engine,  402 ;  Conditions  affecting  the  Design  of  the  Steam-
Kngine,  46G;  the  Problem  stated,  466;  Economy  as  affected  by  Pressure  and
Temperature,  467 ;  Changes  which  have  already  occurred,  46S ;  Direction  of
Changes  now  in  Progress,  470 ;  Summary  of  Facts,  471;  Characteristics  of  a
Good  Steam-Engine,  473;  Principles  of  Steam-Boiler  Construction,  4TC.
LIST    OF    ILLUSTRATIONS.
FRONTISPIECE  :  The  Grecian  Idea  of  the  Steam-Engine.
