18 W. J. M. Rankine on the Means of 



Pressures. Volumes. 



lb. per lb. per 



sq. inch. sq. foot. 



At the beginning of the 1 12() ^ 28Q 



expansion, .J 



At the end of the ex- 1 ork - ., ertr , 



> oU 11,520 



pansion, 



cubic feet, cubic feet, 

 per lb. air. per lb. coal. 



3-4186 856-358 

 5-1279 1284-537 



Space through which the air expands, 

 = space traversed by the piston. 

 Mean Pressures. 



53-5 7707-09 13,173 3,300,000 



1-7093 428-179 



Power = Mean Pressure 

 X Space. 



lb. per lb. per in ft.-lb. 



sq. inch. sq. foot. per lb. air. per lb. coal. 



Mean pressure and ] 



power during the I 97-3 14012-88 23,953 6,000,000 

 expansion, . J 



Deduct mean pres- 

 sure and power 

 during the com- 



611 



pression = 



F 1111 



of the above, 



Effective mean pres- 

 sure and power, 

 500 

 1111 

 Theoretical minimum consumption of coal per horse-power 



per hour. 



l^ooo _ . 731bj 



2,700,000 ~ 

 as in Example IV. of the table in article 10. 



Synoptical Table of the preceding Examples. 



43-8 6305-79 10,780 2,700,000 



Reference. 



Working substance. 



Temperatures. 



Effective 



mean 

 pressure, 



lb. per 

 square ft. 



Spaces 



Effects 



Ordinary 

 Fahr. 



Absolute 

 Fahr. 



Per lb. of coal. 



A 



B 

 C 



Steam (maximum 

 pressure 41*93 

 lb. per square 

 inch = 6038 per 

 square foot). 



Air (maximum 

 pressure 120 lb. 

 perinch=l7,280 

 per square foot). 



Air (maximum 

 pressure same as 

 above). 



\ o 



270 

 ► & 

 140 



) 270 

 f 140 



•) 650 



& 

 J 150 







731 ) 

 & 

 601 J 



731 ) 

 601 J 



1111 1 

 611 J 



1200-46 



2492-03 

 6305-79 



Cubic feet. 

 888-82 



428-179 

 428-179 



Foot- 

 pounds. 



1067000 



1067000 

 2700000 



