496 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



phase 11. The diagram illustrates the impossibility of carrying II 

 into the region of stability of either III or V, but the possibility of 

 subcooling both III and V into the region of 11. 



TABLE XVI. 

 Data for the Equilibrium Curve Ice II-Ice III. 



The experimental values of A V so found are given in Table XVL 

 and Figure 17. The actual volume of II is seen to be less than that 



of III. The percentage 

 discrepancy of two of the 

 points may rise as high as 

 2 per cent, but this means 

 only a comparatively slight 

 absolute error, less than 1 

 part in 2000 on the original 

 volume. The A V curve is 

 convex toward the tempera- 

 ture axis which is unusual. 

 The values for A^ and 

 A^ deduced in the usual 



Figure 18. The latent heat and the change W are given in Table 

 of internal energy when II passes to III. XYLL and l^igure 18. Ill 



gives out heat on passing 

 into II and absorbs work. But the mechanical work is comparatively 

 small, so that the internal energy of II is less than that of III. 



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-33° -31° -23 -zr 

 TEMPERATURE 



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