A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



is the reduced reading of the mercury gauge and p' the vapor pressure of water 

 vapor, 



p/pf=(P-p) (l- 



The correction d$/$, being by the table .7/293 = .0024 or about i per 

 cent., may be neglected. Hence y = p'/p=i 8p/(P-p'), where dp is the pres- 

 sure difference selected. Thus in table i, N, not corrected for time losses, etc., 



would be 



N = y*= lo * l ey where y=. 77 and N=io~ II3S0 . 



In this way the auxiliary ratios n'/N in the tables were constructed. This is 

 the first departure from the method of my earlier work (Smithsonian Contribu- 

 tions, No. 1373). 



TABLE 2. AIR TEMPERATURE ' IN CONDENSATION CHAMBER DURING AND 

 AFTER SUDDEN EXHAUSTION AND DURING INFLUX. 



1 Irregular march after exhaustion due to unsteady earth field. 



2 Throw on sudden exhaustion. 



3 March on filling slowly with filtered air. 



9. Time fosses. Nuclei apparently decay spontaneously in the lapse of 

 time, t, and a correction is to be added to N. Since this loss is relatively small 

 in view of the short time intervals occurring above, w = I io 3( '~' l) may be 

 assumed for convenience. Hence if n be the nucleation due to a given corona 

 seen at low pressure or the identical nucleation at atmospheric pressure after 

 filtered air has been added, the next corona after z exhaustions and t minutes 

 will correspond to n, = n I0 zl By+ ' i0 -' l) whence 



