42 NUCLEATION OF THE UNCONTAMINATED ATMOSPHERE. 



TABLE 23. Decay of X-ray nucleation in lapse of time. Exposure, 3 minutes; 



1817 '' 



6 cells. 



Goniometer close up. 



* Narrow spindle throughout A side. 



TABLE 24. Fog limits obtained with X-ray nuclei. X-ray bulb at different distances. 

 Exposure for different times. Line of sight 15 cm. from end of fog chamber. 

 Goniometer close up. 



* Spontaneous condensation in dust-free air. f Distorted coronas. \ About. 



38. Fog limits of nuclei produced by X-rays. To obtain lower fog 

 limits than were producible with the weak radium above employed, 

 the following experiments with the X-rays (table 24) were undertaken. 

 Even here the radiation is not strong (coil with 4-inch spark gap and 

 energized by 4 storage cells). 



