74 ,.|;OF. C. FKKWKN JKXKIN AND MR. D. R. PYE ON THE 



Alao, by a well-known property of constant-pressure lines, 



Area RGBN = RGAM 



which can be read off the I curves. 

 Taking any experiment of Series I., we have 



Area BQ, given by Series I. (column a, Table VI.) ; 

 EQ, which may be calculated from the specific heat of the gas obtained by 



Series III. (column y, Table VI.) ; 

 GN = I, ID read off the I curves obtained by Series II. (column S, Table VI.). 



Whence the latent heat, L = BQ-EQ + GN, may be found. 



On the same assumptions an approximate 6<j> diagram may be constructed. 

 Starting at the zero-point on the 6<f> diagram (9 = 273 C. abs., = 0) plot, step by 

 step, the constant-pressure line corresponding to the curve of I, remembering 

 that on the 6<j> diagram the area under each element of the curve is equal to 

 the corresponding difference of I ; this is quickly done since the curve is almost 



$ T R 



ft JV 



Corrected $t diagram 

 for freezing machine cycle. 



Fig. 7. 



Since we are neglecting changes of volume of the liquid, this curve will 



with the liquid limit curve (as it practically does in the Steam diagram). 



the gas-limit curve, mark off the values of L/0 for various temperatures, 



the hquid-limit curve and measuring to the right ; joining up the points 



