Till; TIIKKMitltYNAMICAI. l'l;< U'KKTIES OF SUPERHEATED STEAM. 35 



volume takes place between the temperature of saturation and a degree or two 

 alxwe this temperature, and it is probable that this sudden expansion is due to the 

 same cause as that for which the calculation has been made on p. 34, and referred to 

 on pp. 24 and 25, namely, that the volume of dry saturated steam as given in the 

 usual steam tables is not the maximum volume which can exist at that particular 

 temperature of saturation. 



The experimental results given by HIRN are placed in the accompanying Table VIII. 

 as affording the only means of comparison as yet obtainable. An examination of this 

 table will show that no great difference exists between the calculated results and those 

 obtained by HIRN, though the constancy of CK P has been assumed beyond the 

 temperatures obtained in the experiments. 



TABLE VIII. On the Densities of Superheated Steam.* 



* In these calculations, the value of J used has been taken as 774, a number recently adopted by 

 Professor PERRY (in ' The Steam Engine '), and more in accordance with recent researches than the 

 number 778. 



t PKUUY, ' Steam Engine,' p. 577. 



I Volume of 1 Ib. of dry saturated steam in cu. feet as given'.in steam tables, 



F 2 



