TRANSACTIONS OF THE SECTIONS. 



407 



The three most rainy months of the year 1832 were June, 

 August, and November. 



For June we have, 



By calculation , 



By observation 

 For August, 



By calculation , 



By observation 

 For November, 



By calculation , 



By observation 



6. From these comparisons it appears to follow, that though 

 the exact relation between the diminution of rain and the 

 height of the station can hardly be considered as satisfactorily 

 determined by the experiments of twelve months, the nature 

 of this relation is so far ascertained that we may conclude it 

 to be constant for all periods of the year, and that the form 

 V' ^ is a good first approximation. 



7. The account of Dr. Heberden's experiments on West- 

 minster Abbey does not state the elevation of the stations ; 

 yet if we take the height of the square part of the roof at 

 about 120 feet, and from this infer, according to the formula, 

 the height of the house-top which was the middle station above 

 the point below the house-top which was the lowest station, 

 we shall still be able to use those experiments as a check upon 

 the law of the ratio now given. In this case, \/ h = 1 1 '0 

 and 4*6, and we have 



For the whole year. 



By calculation (»« = 4"23) . . b'6'b 



By observation bc)'b 



For the 7 coldest months. 



By calculation {in = 4"2C)) , 53* 1 



By observation b'i 



For the 7 warmest months. 



By calculation [in = 3*90) . 57*1 



By observation 57 



For the 5 coldest months, 



By calculation [in = 4-70) . 48-3 



By observation 48 '6 



For the 5 warmest months, 



By calculation {in — 4-19) 53-9 



By observation 54'5 



80-5 

 80-5 



80-4 

 80-5 



81-9 )> to 100. 



82 



78-3 

 78-0 



80-6 

 80 



