Manchester Memoirs, Vol. xlv. (1901), ^o. 3. 5 



Table II. 

 Table of Specific Heats Kp in Superheated Steam. 



Temp. 

 Fahrenheit. 



fromeq. (2)fromeq. (i 



Temp. 

 Fahrenheit. 



Kr 



from eq. (2)!fromeq. (l) 



290-3 



309'5 

 325"i 

 338-5 



35o*i 

 36o'6 



370-1 

 378-8 



•560 

 •573 

 •531 

 ■594 

 -641 



■734 

 •744 

 •710 



•595 

 -641 

 -674 

 -699 

 •720 

 •737 

 •753 

 •766 



386-8- 



394-3 

 401-4 

 407-9 

 414-2 

 420-4 

 4265 



-694 

 -694 

 -706 

 ■711 

 -700 

 -686 

 •756 



-777 

 •787 

 •796 

 •804 

 -812 

 -819 

 •826 



It will be noticed that the variation of K^ given by 

 equation (2) is of the same nature as, but slightly less in 

 amount than, that given by equation (i). This difference 

 would have been reduced if a slight variation had been 

 allowed in the value of (f )/s we approach saturation. 



Recently, however, determinations have been made of 

 the value ofV.by an absolute method,* and, from the 

 few figures published, it appears that the results confirm 

 the statement made above, viz., that Regnault's linear law 

 of variation of total heat with temperature is incorrect. 



III. On the equation of adiabatic expansion in Superheated 



Steam. 

 From the knowledge of the total heats of formation 

 of superheated steam, given in the first part of this paper, 

 it is possible to utilise the results of Ramsey and Young's 

 experiments on the densities of superheated steam to 

 determine whether the adiabatic law of expansion in 

 superheated steam could be expressed in the form 



pij" = constant, 



the data in the superheated condition being given by the 



* Callendar, Proc. Koy Soc, Vol. 67 (1900), P- 279- 



