an Elster and Geitel Electrical Dissipation Apparatus. 491 

 Table XI. — Influence o£ Wind Direction. 





a+. 





a 







Q- 





P. 



Wind Direction. 



N. 



E. 



S. 



W. 



N. 



E. 



S. 

 16 



W. 







11 



N. 



8 



E. 

 9 



S. 

 10 



W. 



9 



N. 

 10 



E. 



22 



S. 



\V. 

 2 



Times first ... 



4 



3 



19 



10 



4 



5 



second... 



6 



4 



7 



19 



6 



4 



8 



18 



13 



5 



6 



12 



18 



4 



8 



6 



third ... 



16 



10 



3 



6 



15 



10 



4 



6 



7 



12 



7 



9 



6 



1 



12 



16 



fourth . . . 



10 



13 



5 



1 



11 



11 



6 



i 



8 



4 



11 



6 



1 



3 



12 



12 



with a N. or E. wind, and 3 o£ the 4 months in which P was 

 highest with a S. or W. wind. Confining ourselves to firsts 

 and seconds in Table XI., and combining East with North 

 and West with South, we obtain the following figures for 

 Winter (i.e. 12 months of the 36) : — 



Number of 



North and East. 



South and West. 



«+• 



a~. 



P. 



a + . ' a-. 



P. 



3 

 5 



i Firsts 



5 



4 



7 

 4 



9 



7 



7 5 



8 8 



j Seconds 



In the case of dissipation South and West have a distinct 

 majority of seconds, but absolutely no majority of firsts. 



The influence of wind direction is a complicated question. 

 Kew Observatory is situated in a large park, which is bounded 

 on the east by the extensive Kew Gardens, and to the north- 

 east across the Thames lies Syon Park. No inhabited 

 buildings are at all near in the direction from S.E. to N., 

 while Isleworth approaches to within J of a mile across the 

 river in the N.W. direction. St. Margarets, the next suburb 

 up the river, follows immediately on Isleworth, and extends 

 to Twickenham. Richmond is about | of a mile away in 

 the direction from S. to S.E., and behind Richmond lie 

 Richmond Park and Sheen Common. Thus there is a com- 

 paratively narrow fringe of houses — mainly dwelling-houses — 

 extending round from IST.N.W. through W. to S.E. within a 

 mile radius, while from N.N.E. to E. there occurs the great 

 mass of London, but few houses come inside a \\ mile radius. 

 Sometimes when the wind is easterly the curtailment of day- 

 light by London smoke is very apparent, but this is mainly 

 in the winter months when the influence of wind direction. 







