(j8 Rainfall, Natural Drainage, 



during the ten years 1850-51) ; while at Greenwich, in the same 

 period, the averag^e rainfall was 2428 inches. 



The monthly distribution of rain throughout the whole of 

 England varies not less than the total annual rainfall. October 

 and March are, however, almost always and everywhere the 

 wettest months, while February and November are the least 

 rainy. Of the rest, April and August are wetter than the other 

 months not mentioned. The average fall of rain during the six 

 summer months is greater than that during the Avinter months in 

 the ratio of 6 to 5 ; but during the three warmest months, when 

 evaporation is greatest, the average rainfall is almost the same as 

 the mean monthly rainfall of the whole year. Almost every- 

 where in England the heaviest rains fall in October, and the 

 fewest heavy rains in February. In the other months there is a 

 great difference at different stations. Thus May and September, 

 which in most places have either more than, or as much as, the 

 monthly average, have not much more than half the average at 

 Seathwaite. Many other peculiarities of the same kind are 

 noticeable. 



In a general way there is more rain in hilly than in flat dis- 

 tricts. This is, no doubt, partly due in England to the greater 

 prevalence of hilly country towards the west and south of our 

 island, where, on other accounts, the excess of rainfall takes 

 place, but it is an universal phenomenon, and results, at least 

 partly, from physical configuration. Much more rain, however, 

 lalls close to the earth than at a moderate height in the air, 

 therefore the rain-gauge should always be placed near the earth, 

 and its exact position noted and recorded, if we would make 

 accurate observations. At York Professor Phillips many years 

 ago established this fact, and found that of three rain-gauges — 

 one on the ground, one at 44 feet, and the other at 213 feet 

 above the ground — the rain collected during one year was 2 6 '71, 

 19*85, and 14-95 inches respectively. 



At Greenwich, in 1864, there fell 16'34 inches close to the 

 ground ; at the height of 10 feet above the ground the quantity 

 was 16*09 inches; at 22 feet 4 inches only 13*85 inches; at 

 38 feet 4 inches 11*96 inches; and at 50 feet 8 inches, only 

 10*40 inches. The site of the lower gauges is about 156 

 feet above the sea ; of the hio-hest about 205 feet. It is certain 

 that the increased rainfall on hilly ground and on mountain-sides 

 is due to local conditions, among which the position of the sea 

 is one of the most important ; but there are many exceptions, 

 both real and apparent, to every rule that can be stated in refer- 

 ence to this subject. 



In ordinary years the largest rainfall' in the British islands is 

 to be found in the Lake District of Cumberland and Westmore- 



