AT DIFFERENT DEPTHS. 



127 



limit at different places with any accuracy, are 

 far from numerous ; however, from these few, so 

 far as they are known, we learn most distinctly 

 that the influences of summer and w r inter are more 

 and more retarded as the depth increases, and 

 that the monthly and yearly oscillations converge 

 more and more to a certain mean result. 



Thus Quetelet obtained at Brussels, from 

 observations made during several years, at the 

 same time of day — namely, at noon — the following 

 mean values : — 



Depth 







Excess of the 







in 



Annual Mean in 



Maximum over 







Parisian 



ees of 



the Minimiun of 



Date oi occurrence ot tne 



feet. 







the Year. 









Centi- 



Fahren- 



Centi- 



Fahren- 











grade 



Scale. 



heit 



grade 

 Scale. 



heit 



Maximum. 



Minimum. 





Scale. 



Scale. 



















d. h. 



h. d. 







990 



4948 







July 



22 



Jan. 22 9 



0-58 



971 



49-82 



13-89 



25 





26 8 



Feb. 2 9 



1-38 



1007 



5015 



12-82 



23-07 



35 



31 1 



11 4 



2 31 



10-31 



50-56 



12-06 



21-71 



Aug. 



5 4 



21 8 



3-08 



1116 



5209 



10-44 



18-79 





8 3 



24 8 



12-00 



11-99 



53-58 



4-61 



8-29 



Oct, 



12 5 



April 21 7 



21-00 



11-88 



53-38 



1-48 



2-46 



Dec. 



12 



June 18 5 



In the first of the above columns you will find 

 the depth at which the thermometer was placed 

 below the surface ; in the second, the mean tempe- 

 rature of the year at these several depths; the 

 third shows the respective differences of the high- 

 est and lowest temperature of the year ; and the 

 fourth the point of annual time at which the high- 

 est and lowest temperatures respectively were 

 reached, at the different depths. 



