68 



CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



TABLE 29. Dust-free wet air ionized by X-rays at I? = 50 cm. Bar. 75.9 cm.; 



temp. 21.3 C. 



'\vp corona. 



-/-39 MC MS 



.Zi 



.39 



FIG. 20. Nucleation n of dust-free air and of ionized air in terms of relative adiabaticfl 

 drop in pressure dp/p and of volume expansion vjv. Enlarged scale for n. Region^ 

 for ions. 



FIG. 21. Nucleation n in terms of relative adiabatic drop of pressure dp/p, and of 

 volume expansion "vj-v for dust-free air not energized, and for dust-free air acted on 

 by the beta and gamma rays of radium and by the X-rays from different distances D. 

 W refers to C. T. R. Wilson's condensation and fog limits, B to my own; T shows 

 J. J. Thomson's results referred to scale of the diagram. Several older series, V to X, 

 are given for dust-free air. 



40. Graphs. Dust=free air. The charts (figs. 20, 21, and 22) con- 

 tain a number of curves showing the nucleation in different scales (com- 

 puted from the angular diameter of coronas) in terms of the exhaustion. 

 In figs. 20 and 21 typical cases are given, in their lower parts only. Fig. 

 22 contains full curves on a smaller scale. Thus the curve for the vapor 

 nuclei of dust-free air begins appreciably below dp/p = o.26 (v 1 /v = i .24, 



