4 Grindlev, Therviodynamics of Superheated Steam. 



•305 is far removed from the mean value of —r- between 



the range of temperatures given in Table I., and a small 

 alteration in its value would make no appreciable difference 

 to the figures in the table. 



For further evidence on the value of A',,, the author 

 has taken the results of Ramsey and Young's experiments* 

 on the densities of superheated steam, and from them has 



obtained values of [^) in superheated steam at various 



pressures. This, however, was only possible when dealing 

 with steam not near the saturated condition, as near that 

 condition the results were interfered with by surface 

 condensation. 



Assuming that the values of (-7-) , obtained for 



superheated steam, could be taken with very little variation 

 to hold near the saturated condition, various values of 



( — ) were obtained and used in the formulaf 



---^^<aciL ■ • • <^' 



to determine the values of Kp in superheated steam near 

 the saturated condition. The number 1438 in the formula 



presumes an accurate knowledge of — , and is obtained 



by assuming Regnault's linear law ; it is therefore liable 

 to the same source of error as in the previous determina- 

 tions of Kp. 



The values so obtained are given in the following 

 table, along with values obtained from the equation (i). 



*0n the properties of Water and Steam. Phil. Trans. (1S92), p. 117. 

 t For proof, see Perry's " Steam Engine," p. 580. 



