A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



119 



TABLE 7.— MISCELLANEOUS EXPERIMENTS. ROOM AIR FROM FLOOR. LARGE 

 VESSEL. ^'^=6.23;''. EXHAUST THROUGH STOPCOCK. 



EXHAUST THROUGH INSTANTANEOUS VALVE. 



from coronas. No doubt this is in part due to adhesion; but the chief reason 

 is the occurrence of so many large particles with the small, so that the average 

 value of d given by the photographs is within certain limits an arbitrary cjuan- 

 tity, depending on the distribution of particles selected for measurement. If 

 the values of d be plotted graphically in terms of s, they do not make a smooth 

 curve, and these values are from 1.5 to 2 times larger than the coronal values 

 of d. For this reason the measurement of d in the photographs was abandoned. 

 The data are much inferior to the above micrometer measurements of floating 

 globules. 



The w-values in the photographs, being obtained independently and not 

 conditioned by so perfect a reproduction of form, etc., as are imperative in 

 measuring diameter, may be considered more trustworthy. Nevertheless, they 

 also fail to suggest a smooth curve, though they are, as a whole, very much 

 smaller than the coronal «-values. If observations obviously in error be 

 omitted, the following are the mean values of the ratio n (coronal) to n 

 (photographic) obtained from the successive tables. Only in two or three in- 

 stances are these ratios less than one. 



= 5-9. 



or on the average the coronal n-values are about 4^ times as large as the n- 

 values obtained from the photographs. 



