20 



THE BRITISH ISLES. 



winds are most frequent between January and May. They are dry and cold, 

 checking the vegetation in spring, and are frequently productive of those dense 

 fogs which have given the British climate so unenviable a reputation. 



To the annual amount of rain, and its distribution over the year, the British 

 Isles are largely indebted for their fertility, and under this beneficent influence 

 even naturally sterile tracts, which in many other countries would present an 

 aspect of desolation, become covered with a carpet of verdure, and afibrd at least 

 succulent pasturage to sheep. Even in the eastern counties, which are less 

 exposed to the westerly moisture-laden winds, the rainfall is ample, and numerous 

 rivers and rivulets irrigate the soil. On an average far more rain falls than in 

 France,* and though, owing to the greater humidity of the atmosphere, the 

 amount of evaporation is less, the area occupied by marshes is of small extent. 

 In England this circumstance is due to the undulations of the soil, which 



facilitate the drainage of the land ; whilst in Ireland the surplus waters collect 

 in lakes, occupying rock}^ cavities, or are sucked up by peat bogs, without filling 

 the air with pestiferous miasmata. 



The rainfall is most considerable in the west, because the mountain ranges 

 extending north and south intercept the westerly winds which travel across the wide 

 expanse of the Atlantic, and compel them to part with most of the moisture they 

 carry. In Ireland the quantity of rain increases gradually as we proceed from the 

 west to the east coast, and the same phenomenon, on a larger scale, may be observed 

 in Great Britain. Nowhere else is the influence which mountain rangées exercise 

 upon the distribution of rain more strikingly exhibited, its amount being in every 

 case most considerable along the western slope. At Whitehaven, which lies at 

 the western foot of the Cumbrian hills, the annual fall of rain is 47 inches, whilst 



Average rainfall in France (Dclesse) 

 ., „ Great Britain 



„ „ Ireland 



SO inches. 

 33 „ 

 36 „ 



