208 Influence of the Physical Character 
very dissimilar to that which marks the era of the later Coal 
formation would flourish luxuriantly, affording sustenance to 
tribes of animals suited to such conditions of life. 
It is far from my present purpose to enter largely into this 
branch of the subject; it 1s only necessary to show how 
materially configuration regulates the intensity of heat and 
cold; how a chain of lofty hills may serve as reservoirs of con- 
gealed waters, whence rivers are supplied unceasingly ; how 
low level plains, by favouring evaporation, and yet preventing 
the formation of rainclouds over their surface, either become 
arid and desolate wastes, or swampy jungles. This is not only 
true of continents and large islands, but in lesser proportion is 
known to influence districts of small area. <A lofty hill some- 
times makes a perceptible difference in the rainfall -in its 
neighbourhood; a plain of a few miles in extent is sufficient 
to give a distinctive character to the climate within its limits. 
A difference in the superficial features of a country will not, 
however, always explain vicissitudes of climate over limited 
areas. The rainfall, more especially, is largely affected by the 
direction of the winds. I am anxious to show the superiority 
of not one particular cause, but rather to recognise them all. 
Perhaps the best argument I can use is to refer briefly to the 
almost inexplicable variations of the rainfall in places very 
near to each other. 
Instances of Variations in the Rainfall.—The mean fall of 
rain for the whole of England is stated to be thirty-six inches, 
but near London there is a fall of twenty-three inches, and in 
Cumberland sixty.* The unequal fall of rain in Scotland is 
also remarkable; the average in Glasgow is rather more than 
twenty-nine inches, in Edinburgh it is twenty-three; and 
this within a distance of forty miles! In the south-west of 
Ireland the rainfall is forty-two inches, in Armagh it is about 
twenty-two. ; 
The inequalities of climate being so palpably influenced by 
such a variety of causes, we ought to reject every calculation 
that is not based on actual observations within the locality,, 
to whieh such observations have reference. 
The Mean Annual Temperature also presents great differ- 
ences in different localities, and in countries within the same 
parallels of latitude. As an instance of .this I may mention 
the mean temperature of Switzerland, viz., 47°, which 
* Sir Charles Lyell mentions the following variations :—‘ At Whitehaven, in 
Cumberland, there fell, in 1849, 32 inches; while the quantity of rain in Bor- 
rowdale, near Keswick, (only 15 miles to the westward,) was no less than 142 
