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PROCEEDINGS OF THE AMERICAN ACADEMY. 



of the density of water up to 320°C. Furthermore, the pressure of 

 saturated steam has been observed up to the critical point itself by 

 a number of observers, of whom Cailletet and Colardeau 52 seem the 

 most trustworthy. From their values and the extrapolation formula 

 for L, one can compute the change of volume during vaporization up 



Figure 16. The steam dome on the temperature-density plane, with 

 the "straight diameter" of Cailletet and Mathias, and the critical point 

 according to Nadejdine (N), Battelli (B), Dieterici (D), and the present writer. 



to 320° and indeed up to the critical point itself. The sum of these 

 values and the volumes of the liquid mentioned above are the volumes 

 of saturated steam up to 320°. The results are tabulated below and 

 are plotted in Figure 16. The diameter is seen to be, as usual, nearly 

 but not quite straight. It is not possible to represent the whole of it 

 even by a third degree formula in t, because of the peculiar behaviour 

 of the density of water at low temperatures. The 20 points above 



62 Journ. de Phys., 1891, 10, 333; also Ann. Chem. et Phys., 1892, 25, 

 519; also Physik. Rev., 1892, 1, 14; also a short note in C. R., 1891, 112, 

 563; see also Risteen, The Locomotive, 1907, 26, 219. 



