38 CONDENSATION OF VAPOR AS INDUCED BY NUCLEI AND IONS. 



diameters are increased (caet. par.) and vision is at an advantage as to 

 clearness. Test experiments made with definite coronas showed that the 

 aperture 5 of the old goniometer was about equal to 0.9 5 of the new, and 

 with this number the reductions needed were made with the results given 

 in table 14. The apparatus showed the same corona for the same dp/p 

 on a number of successive days, so that fixed conditions had been reached. 



TABLE 14. Efficiency of the small fog chamber, No. 3, with special goniometer. 

 Length 16 cm., diameter u cm., 2-inch exhaustion pipe. Dust-free air and ionized 

 air. Radium I .... V, axially placed. 



*Note different apertures for the same color. 

 tCoronas.decreasmg with increasing precipitation. 



