DAVIS. — A PQ PLANE FOR THERMODYNAMIC CYCLIC ANALY'SIS. 647 



plane will be ilimiiiished by the same amount. To the point P= 1, 

 ^ = (and indeed to the whole of the lines P = 1 and ^ = 0) no 

 physical meaning can be attached ; and any final temperature from ab- 

 solute zero to infinity may be found in any neighborhood of this singular 

 point. 



The V curves of Figure 15 are much simpler than those for the other 

 two types, the final velocity depending only on the "quality of the 



150 



300 



450 500 



QinBTU 



200 250 



Figure 13. 

 Tijpe B. Locus of points S. The full lines are velocity curves and tiie dotted 

 lines arc efficiency curves. The points of tangency lie on the locus indicated. 



mixture." The B curves are represented in Figure 17, except that por- 

 tions of all of them near their common intersection at the singular point 

 have been omitted. Any eflSciency from — go to + 1 is possible in any 

 neighborhood of this point. The W curves (Figure 18) are all alike, 

 and are the ^ = curve indefinitely repeated at constant intervals. The 

 V 7\ area (Figure 16) differs from those for the other types chiefly in 

 that it extends upward indefinitely. Fortunately the V T corner is al- 

 ways the best point in the area, not only for work, but for efficiency as 

 well. 



