274 Prof. If. L Callendar. On 11 'dynamical 



Table I. Specific Volume and Co-aggregation of Steam. 



The values of the specific volume r are calciilated for the saturation- 

 pressures, given in atmospheres in the second column. The values 

 for any other pressures can he calculated with equal ease, since the 

 co-aggregation-volume c, which is given in the third column, depends 

 only on the temperature. It is 7 necessary in each case to calculate the 

 appropriate value of the ideal volume V = HO/p. The values of the 

 specific volume v are found by subtracting (c - 1} from the ideal 

 volume. The values of the co-aggregation ratio c/V, and the deviation- 

 ratio (c - b)/V, are also given, as the first is useful in calculating the 

 values of the specific heats by formulae (9), (10), and (11), and the 

 second affords the most convenient means of representing graphically 

 the variations of the specific volume, since it is quite impracticable to 

 piot the specific volume itself on an adequate scale. 



Graphic Representation of the Variations of Specific Volume. 



The best method of representing these results graphically appears to 

 be that adopted in fig. 1, of plotting the ratio of t?/V or (c-6)/V 

 against p. We have 



pv[R6 - t;/V = l-(c-J)/V = l-(c-b)p[RO (27). 



Since r is constant at constant temperature, the isothermals are 



