120 NUCLEATION OF THE UNCONTAMINATED ATMOSPHERE. 



85. Comparison of the data for Providence and for Block Island. A 



discussion of the details of the type of results obtained for Providence 

 has already been given in the Smithsonian report (loc. cit.), and the 

 new data add no essential novelty. It will suffice, therefore, to com- 

 pare the two classes of curves throughout their extent. 



Figures 95 to 101 show the daily record of the nucleations of Provi- 

 dence (upper curve) and of Block Island (lower curve) in thousands 



20 



/8 /3 20 2J 22 23 24- 25 ZG 27 28 

 FIG. 95. Showing daily record for November i to 29. 



of nuclei per cubic centimeter for the dates given by the abscissas, 

 i.e., from November, 1904, to May, 1905. The prevailing winds and 

 weather and the temperatures of both places are roughly given on the 

 curves. 



In the earlier results, from November, 1904, to January, 1905, there 

 is as yet no striking opportunity for comparison, except that both 

 cases show a general rise of nucleation to the high maximum follow- 

 ing December 14 and December 20. It is clear that similarity in the 



