24 



A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



the charge on the condenser vanishes. The average value of the conduction, 

 moreover, is quite of the order of values found for phosphorus nuclei in the above 

 tables, under similar circumstances. As the data in the table show a for succes- 

 sive minutes, its variation in the last series is from .223 to .872 in 3 minutes. 



Since 2.3 aC= i/R, where (7 = 8/ 10" farads is the ca^^acity of the condenser 

 and appurtenances, the initial and final resistance would be 



i? = 25Xio'' and R^GXio" ohms. 



It follows then that if the equation of the current be taken, or 

 io:n{U + V)c (E/l) in the usual notation, the number of charged nuclei, n, 



ZO mtU. 



no .cm. 



omm. 1 



20MTI, 



/ 2 



AOxio'lU. 



QWjlt / 



WWR 



40voUs. 



want 



7.omv 



focm 



OTrmi. 1 



Figures 4, 5, 6. — Curves Showing Electrometer Deflection (Leakage) after consecutive 

 Half Minutes, for Different Charges and Potentials in the Condenser. 



increases as the potential difference, E, diminishes. The same is true for the 

 negative current with a smaller coefficient. 



The results for the conduction, a, become more interesting if the electro- 

 meter deflections are charted graphically in relation to time as in the annexed 

 figures 4, 5, 6. It is thus seen that the current is surprisingly constant, while 

 the initial potential difference of about 20 volts gradually quite vanishes. 



g. Comparison with coronas. — The number of ions which may be com- 

 puted from the given currents is excessive when compared with the number of 



