DAVIS. — CERTAIN THERMAL PROPERTIES OF STEAM. 311 



and of the Joule-Thomson coefficient presented in an earlier paper. In 

 particular the choice of Knoblauch's values of C p as the foundation of 

 the determination of H in this paper is justified. 



5. It is shown that Clausius' specific heat of saturated steam 

 passes its maximum without becoming zero or positive, so that the 

 temperature-entropy diagram for steam must be essentially simpler 

 than that for either ether or chloroform. 



6. The extrapolation formula for L mentioned in 3 above is made 

 the basis of a determination of the critical density of water by the 

 method of Cailletet and Mathias. The result is 



v c = 3.04 cm 8 /gr. 



The specific volumes of water and of saturated steam at other high 

 temperatures have also been computed and embodied in a steam table 

 running up to the critical temperature. 



Jefferson Physical Laboratory, 

 Cambridge, Mass., 



December, 1909. 



