A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 87 



The means of the best values are in the five cases 5 = 4.8, 6.7, 6.3, and 

 5 = 4.5, 5-6. respectively, the mean of all of which is 5 = 5.6. This value is 

 practically the same as in the preceding table for 5^=17 cm. The effect of 

 waiting 2 or 4 minutes between observations" does not appear in the individual 

 results. The decay-effect of waiting i or 2 minutes is apparent, but this is due 

 to the necessarily much more expeditious observation of coronas (time of fog sus- 

 pension) in the former case. Curiously enough, at ^ = 8.5 cm. 5 = 6.5 i s larger 

 than at dp = 22 cm. where 5=5.0. 



The constants for computing diameters of fog particles (d = -\l6m/7rri) are at 

 8.5 cm., io 2 Xd= i.7in~' /3 and at 22 cm., -io 2 Xd=2.2'jn~ 1/3 . Thus at 3p = 8.$ 

 cm. the ratio of distance between centers of cloud particles, n' 1/} , and their di- 

 ameters is 58.4, and at dp = 22 cm. the corresponding ratio is 44.0. It follows 

 then that for the same corona, the distances apart are materially different in the 

 two cases. Hence if the interstices enter into the character of the diffraction 

 pattern and distribution of axial colors, these should be different for the two 

 pressure differences in question. 



TABLE 14. CONSTANTS OF CORONAS. ARC LIGHT, CONDENSATION CHAMBER, 

 AND DISTANCES AS IN TABLE 13. #=21; BAROMETER, 75.6 cm.; 6p = 8. S cm.; 

 ^=.85; /?=o; 5 = 4.8; u' = .oc>34; a" = .oo2g; m=2.6Xio" 6 ; ^,, = 825000; 5 MEAS- 

 URED TO OUTER EDGE OF FIRST RING; PHOSPHORUS NUCLEI; st=i m . 



'Alternative 8580, 4130, 1150, o. 



