64 A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



Thus it is merely necessary to know the relative values of n or the nucleation 

 ratios, and these may be obtained by an}- method of smoothing, by plottiiig 

 n' or .V in tei^ms of s. 



In table i. A*' has been found for each aperture, s, and /3 computed as stated. 

 The values of /i so found are of the mean order of .002. They apparently de- 

 crease toward the end of each series as the number of nuclei grows smaller; but 

 this conclusion is not vouched for, as it will presently be showm that a specific 

 loss of nuclei accompanies each exhaustion. In other words, n = Nr„ (i—nz), 

 where ;-„ is a constant, or the numbers diminish faster than is attributable to 

 time loss alone. The effect will be particularh' marked for the smaller initial 

 time intervals of the original nucleations. 



Accordingly I have made another computation, writing approximately 



n/n' = {N/N') {i+a{s'-z)) 



and finding /i from this by the cijuation already given. These values of /i are 

 inserted in the last column of the table. The}' are irregular in distribution and 

 of the niean value fi=. 0016. 



The chief result of this paragraph is the relatively small value of the co- 

 efficient of time loss of nuclei. Its effect on the results may therefore be neg- 

 lected (tested), particularly as the effect 10°°"'"= 1.004 for ■s=i is in part 

 compensated by the temperattu-e factor 6$/s = .0024 of the preceding para- 

 graph. Direct experiments below ()j>j 27, 28) , where identical results are obtained 

 for different time intervals (2 min. and 4 min.), vouch for this conclusion. Meas- 

 urements of coronal aperture of the present kind, hampered as they are by the 

 difficulties of observation, of reduction, of subsidence, etc., cannot offer more 

 than an estimate of the conditions sought. 



ID. Exhaustion losses. — I shall next consider the independent destruction 

 of nviclei which accompanies each exhaustion, and for which it is difficult at the 

 outset to assign a reason. It will be shown that it is due to the subsidence of 

 fog x^articles. This loss did not appear in my original investigations, probably 

 because the spherical receiver iised was not lined with wet cloth. 



From what has preceded, the relative number of nuclei after z exhaustions 

 is 10' '"'''^', whereas in the region of normal coronas the absolute number is 

 certainly very nearly n' = Cs\ where C is a constant. This will be independently 

 verified presently by special experiments. Hence the ratio r = C5'/io"'°'^^ 

 should be constant, whereas experiment and the charts, figtu-e 5, show (roughly) 

 that r = r^ {i — nz), a being the coefficient of exhaustion loss and r^ = CsJ the 

 arbitrary initial ratio for z = o, preceding the first corona observed. Thus 



aS=(l-(5/5jVlO-"'--"). 



If r = o for z = z', i/z' = n, so that n appears as the reciprocal of the abscissa 

 underlying the positive ordinates in the first quadrant, and may be taken at 

 once from the graphs. These values are given at the head of each table. 



