44 CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



TABLE 15. Distribution of ionization. Fog chamber no cm. long, 12 to 20 cm. in 

 diameter. Sp/p = 25/76 = 0.33. Distance D from brass or exhaust end turned 

 toward glass or closed end. Radium at d. 



* Core charged to 250 volts. 



t Core uncharged. 



t Influx at large end. 



The results are also shown in the charts figs. 13, 14 and 15, the two 

 latter being the more typical. The abscissas indicate the position of the 

 axial radium tubelets measured in centimeters from the exhaustion end 

 of the fog chamber, the ordinates the observed nucleation. The three 

 curves correspond to three goniometers, placed at 20, 50, and 80 cm. from 

 the exhaustion end, respectively. The results are seen to be of the same 

 nature as those discussed above. 



Fig. 14 shows particularly that the maximum always lies on the 

 exhaust side of the position of the radium. Moreover, the ionization 

 when the radium is near the exhaustion end is always small and nearly 

 uniform throughout. The maxima are largest when seen in the middle 

 (D 50 cm.) and smallest when seen at the exhaustion end (D = 20 cm.). 



