646 



PROCEEDINGS OP THE AMERICAN ACADKMY. 



If, on the other hand, it is desirable to make If^ rather than E as great 

 as possible, the best point of a FT' area is always, as in the case of the 

 Bray ton cycle, the FjT corner, and the best ratio of compression is the 

 same as before. In the case of each of these types it is necessary to 

 choose between efficiency and work, but the two best cycles are now 

 much nearer together than they were before. 



The type B working chart is similar to that for type A, except for 



20 



50 



100 



liO 



350 



400 



450 500 



Q in BTU 



200 250 300 



FiGUKE 12. 



Type B. Work. For isothermal cycles. These curves also have turning points 

 on the "high efBuiency fuel line." (Cf. Figure 7.) 



the presence of the high efficiency fuel line and the locus of points *S 

 which are drawn with long dashes. 



Type C. The Regenerative Cycle. The final temperature curves for 

 type C are shown in Figure 14; they are the T^ curves for type i? dis- 

 placed horizontally but without distortion, until their lower ends, which 

 were scattered along the line P= 1, are all brought to the single point 

 P — 1, (? = 0. This is because T^ is (by definition) constant along one 

 of tliese curves, and so, T^ being fixed, the heat G^{T^— 2\) that can 

 be obtained from the exhaust is the same for all cycles on that curve ; 

 consequently the Q of each point of the curve as drawn on the type B 



