A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



63 



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

 vapor, 



p/p'={P-p) (i-^s/s)/(p'_^'). 



The correction <5S/s, being by the table .7/293 = .0024 or about i per 

 cent., may be neglected. Hence y = p / p=i — sp/ {P-p'), where sp is the pres- 

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

 would be 



iV = y'=io-''°«^where ;y = .77 and A^= lo" •■■'5\ 



In this way the atixiliary 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. 



' Irregular march after exhaustion due to unsteady earth field. 



' Throw on sudden exhaustion. 



' March on filling slowly with filtered air. 



9. Time losses. — 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 intei-vals occurring above, w = w,io**'"''' 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 w, = » io'-'°s >'+^'^'-'-^ whence 



P={i/{t-t:))\og{nJny). 



