640 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



have been omitted from this and the two following charts, as being 

 unimportant. 



Tyfe B. The Isothermal Cycle. The T^ and Fcurves for this type are 

 shown iu Figures 8 and 9. They are the corresponding curves for the 

 adiabatic case, sheared horizontally in such a way that the T^ = T^ 

 curve, which formerly lay along the P axis, has now a position indicated 

 by the dotted line of Figure 8.* All cycles whose points lie on this line 



100 150 



450 500 



Q in BTU 



200 250 300 350 400 



Figure 7. 

 T)ipe A. Work. Tliese curves give the net work in foot pounds which one 

 pound of gus can do while making one complete circuit of a Bray ton cycle. 



* For if the Te formulae (types A and B) be solved for Q, they give 



TfiA=C\[T,-Ta)P " . (a) 



where tQ, stands for the Q of any point of a Te curve for the type A case ; also 



= Cj,(Te - Ta) P~^ + Cp(TaP " - Ta) 



(b) 



