DATA OF VARYING PRESSURE. 



[dp]' that the upper limit of pressure is varied) are strikingly distinct in 

 both figures and that the variation of the lower pressure limit [dp^ 

 corresponds, as it should, to a highly increased efficiency of the fog 

 chamber. The coronal fog limits are far apart, being respectively below 

 [c^li = J 7 4 and [dp]' = 19. 4 cm. in fig. 6, where all data (table 8) were 

 obtained in one series of experiments. 



TABLE 7. Effect of varying p in dp = p-p 3 =P-p m -p 3 . Chamber II. Bar. = /> = 

 P-pm. v/V = 0.064; P~p 2 = o.775 dp; ^=2.3; t= 25 C.; 7r-7r, = i .8. 



"Water nuclei not precipitated. 4 From Carnegie Institution of Washington 



2 Too small. Initial values. Publication No. 62, chapter n, table 26. 



3 Water nuclei precipitated. Coronas usually blurred. 5 Ibid., chapter vi, table x. 



In fig. 5 the results of series I' and II' are taken from data for the 

 same apparatus in an earlier report to the Carnegie Institution of Wash- 

 ington.* Consequently some reconsideration is needed. In the lapse 

 of time the efficiency of the fog chamber has for some reason increased, 

 for the new results (fig. 6 and dotted line in fig. 5) are distinctly higher 

 in nucleation than those quoted from the report. 



*Carnegie Institution of Washington Publication No. 62, chapters n and vi, 1907. 



