2O4 



A CONTINUOUS RECORD OF ATMOSPHERIC NUCLEATION. 



determinable peculiarity. Throughout the month the temperature effect is 

 vague or in opposition to the winter effect. 



1903 20 



5 6 



9 10 11 



CHARTS 20, ai, 22, 23. 



12. August (charts 22, 23, 24) at first shows low nucleation due to fre- 

 quent rains. The rest of the month is somewhat uncertain in consequence of 

 building operations on the college green. Thus the maxima on the 24th and 

 25th are due to fires on the campus. Low Sunday nucleations occur on August 

 2 and 23, the latter being phenomenal. Rapid increase after rain is frequently 

 noticeable, as on August 10, 21, 27, and similar effects may be found in the 

 earlier months. 



13. September (charts 24, 25, 26), in spite of high temperature, clearly 

 ushers in the high winter nucleations, just as March had removed them. The 

 suddenness in both cases is surprising: one naturally asks whether there is here 

 a return to the locality of the nuclei-producing civil activity which had left it 

 in March. But the data of 1904 do not bear this out. The high maxima on 

 September i, 9, 12, 15, 19, 22, 25, 30 are all striking. The Sunday minima on 

 the clear days of September 6 and 13 are not low. The gale on September 17 

 and the thunder-storms on September 5 and 27 are followed by high nucleation, 

 particularly in the latter case, but the assertion that nuclei are produced in this 

 way would be unwarranted. 



14. October (charts 27, 28, 29) sustains the high nucleation of September. 

 Sunday minima (October 4, ei seq.) quite vanish, but the winter temperature effect 

 is not yet resumed. The rain effect on October 5, 12, 17 is obscure, and in the 

 latter case even the rain-storm is ineffective. Rise of nucleation on October 19 



