Starkweather — Thermodynamic Relations for Steam. 141 



t 



h 



H 



L 



P 



V 



Vw 



Vs 



e 8 i 











598-9 



5989 



4-626 



204-97 







935-4 



242851 



10 



10-0 



602-8 



592-8 



9-277 



105-91 



15-5 



908 5 



244072 



20 



20-0 



606-8 



586 8 



17632 



57-653 



30 3 



883-9 



245297 



30 



300 



610-7 



580-7 



31-943 



32-861 



44-5 



861-4 



246524 



40 



400 



614-6 



574-6 



55-449 



19-518 



58-4 



840-7 



247749 



50 



50-0 



618-5 



568-5 



92-610 



12-032 



71-7 



821-7 



248966 



60 



60-0 



622-3 



562-3 



149-40 



7-6666 



84-7 



804-3 



250168 



70 



70-0 



626-0 



556-0 



233-59 



50333 



97-3 



788-2 



251353 



80 



80-1 



629-7 



549-6 



354-94 



3-3953 



109-7 



773-1 



252515 



90 



90-2 



633 3 



543-1 



525-56 



2-3472 



121-7 



759-2 



253652 



100 



100-4 



636-7 



536-3 



760 



1-6587 



133-5 



746-3 



254757 



110 



1105 



639-8 



529-3 



1075-4 



1-1973 



144-9 



733-9 



255724 



120 



120-6 



6429 



522-3 



1491-3 



0-88099 



156-1 



722-6 



256691 



130 



130-7 



6459 



515-2 



2030-3 



065948 



167-0 



711-9 



257649 



140 



1409 



6489 



508-0 



2717-6 



0-50152 



177-6 



702-0 



258615 



150 



151-1 



651-9 



500-8 



3581-2 



0-38707 



188-0 



692-7 



259571 



160 



161 3 



654-8 



493-5 



4651-6 



030278 



1981 



684-0 



260517 



170 



1716 



657-7 



486-1 



5961-7 



0-23982 



208-1 



675-9 



261485 



180 



181-9 



660-5 



478 6 



7546-4 



0-19216 



217 9 



668-4 



262440 



190 



192-2 



663 3 



471-1 



9442-7 



0-15566 



227-5 



661-4 



263394 



200 



202-5 



666-0 



463-5 



11689 



0-12739 



236 9 



654-7 



264336 



The unit here for quantities of heat is the specific heat at 

 15°, pressures are in millimeters of mercury, volumes in cubic 

 meters per kilogram, energy in kilogrammeters (at Paris) per 

 kilogram, and entropy in kilogrammeters per kilogram per 

 degree. 



There is a gratifying confirmation of the formulae given by 

 Dieterici's experimental determination* of the volume at 0° C, 

 which was 204-68 cubic meters. This differs from the value 

 given in the table by only a little over one-tenth of one per 

 cent. When one considers the roundabout way in which the 

 latter was found, the agreement is quite remarkable. Dieterici 

 considers his determination to be correct within one-half of one 

 per cent. 



There are one or two interesting points which can be brought 

 forward concerning the deportment of steam over ice. At 

 0° C. that portion of the energy due to the terms in the 

 formula containing v is only nineteen kilogrammeters, which 

 is entirely negligible compared with the latent heat. Hence 

 for steam over ice we can set 



e=/(T). 



Now if G is the latent heat of ice, and K its specific heat, we have 



c = JL-JK (273-7-T)- JG-p (v-io) . 

 Hence 



JL-JK(2ld-1-T)-JG-p (v-iv)-f (T) = 0. 



*Wied. Ann., xxxviii, p. 1, 1889. 



