THUNDER. 223 



heat, whereas the wet earth produces cold by eva- 

 poration. Besides there is no attraction of cohesion 

 between the dry earth and the water that forms a 

 cloud, while between the wet earth or water, and 

 that water, there is the very same attraction of 

 cohesion by which clouds are accumulated in the 

 sky. The cloud thus comes down to the moist 

 surface, and avoids the dry ; and even those thun- 

 der showers that have their causes on the surface 

 of the earth, follow thick leafy woods and the 

 courses of the rivers. Even in mountainous coun- 

 tries, though the local thunder clouds do sometimes 

 strike the peaks, they much more frequently plough 

 up trenches in those elevated heights, which 

 abound in moist peat earth, and are always 

 saturated with water. That (as indeed all the 

 occurrences which are perfectly natural are when 

 once we understand them) is highly beneficial. 

 Where the cloud strikes it usually falls, and the 

 water which falls upon those heights does not so 

 soon run to waste as if it fell on the peaks. 



When the thunder storm is followed by fine wea- 

 ther, it is said, in common language, that " the thun- 

 der clears the air ;" but though the fine weather 

 follows the thunder, it is no more the cause of that 

 fine weather than the battle in which one party is 

 vanquished is the cause of peace. The thunder is 

 the battle, the resistance made by the bad weather 

 in opposing the good ; and the good weather takes 

 possession of the atmosphere only after it has van- 

 quished and driven off the bad. 



When the bad weather invades any place in a 

 thunder storm, the appearance is often very grand. 

 The wind may have been blowing steadily from the 

 same point for weeks ; and some peculiarly bright 

 day (for the first sign of an invasion of the horizon 



