il. CHERMAL I'kopKRTIES OF STEAM 7 



The experiments of Holborn and IK-nning with steam at atmo*- 

 rcssure and a temperature range of I io-i4OO C. 



4. direct experiments \\ith steam at various pressure*. Of 



these, the e\ -lam h and Jakob and of Knoblauch and 



Moll d in the Muni, h laboratory are specially noteworthy. 



Similar experiments have been made by Thomas. 



..n.mlt's experiments made in 1862* indicated a constant value 



of c v - 0.4805. Davis f has recomputed Regnault's values and has de- 



I asomi-uh.it smaller \alm-. nanu -1\ . <, ".\-i\2. F.r tin- pressure 



and rani^r !" temprraturc covered in tin- e\jeriment. Renault's value 



agrees well with the results of recent fx|x*rimcnts. 



TMM 



FIG. 3. CURVES or SPECIFIC HEAT DEDUCED FEOM EQ. (C). THE Powers 



ER1MENTS OF KNOBLAUCH AND MOLUEft. 



The high temperature experiment^ ntd in group 2 have only an 

 indinvt bearing on the present di-ru i.n. The results obtaiiuxi by 

 tin dirtVivnt iiu'-tigators are discordant, but they all agree in showing 

 a marked increase of specific heat with rising temjHTature. Thus Lan- 

 gen's expt rinit nts are represented by the linear relation 



c* - -439 -H 0.000239 /. 



The experinunt- of Holborn and limning I form a link between 

 the hi.nh temp. c\|HTinients of group 2 and the experiments of 



grnup 4. These measurement^ indicate values : nsixtently lower 



than those obtained in the Muniih e\i>eriim nt>. While considerable 

 weight must be attached to the Holborn and Henning experimn 

 seems probable that preference must be given the Knoblauch and Mollier 



cm. Inst. de France. Vol. 26. p. 167 (1662). 

 roc. Am. Arai! ;. 286 (1910). 



I Annakn der Ph>-sik. Vol. 18, p. 739 (1905); VoL 23, p. 809 (1907). 



