THE STATE OF THE ATMOSPHERE. 391 



upon a close examination of the facts and the arguments set forth in 

 writing by the two parties themselves, had to find a verdict in favour of 

 both. The one had formed his opinions from his own experiences of the 

 Dee, the other his of the sister river, the Don. My own knowledge of the 

 peculiarities of these rivers is intimate and of prolonged duration. 



I have often met with success on the Dee during a flow of snow 

 broth, but never on the Don, and yet these two rivers empty themselves 

 close to each other. 



I may refer here to a curious coincidence which once happened while 

 fishing the Don. There was no snow at the time of any importance. 

 With me sport was at a standstill, whilst the accounts from the Dee were 

 excellent. One day it rained for six or seven hours, but the storm was 

 local and did not extend to the Dee. For several days I watched the state 

 of the weather, and kept up a correspondence with friends in the other 

 district, with the result that I found it varied considerably. Cloudy 

 weather and fogs prevailed with us, while the sun shone brightly on the 

 others. Either of the two former conditions usually tends to quickly lower 

 the temperature of the atmosphere. Even the deposit of dew makes a 

 difference of a few degrees. In my observations I found out that the 

 nature of the soil and the degree to which it is covered by vegetation 

 affects the temperature of the climate, changes it, and spoils sport. 



If we carried our thoughts to the sandy deserts of Arabia, we could 

 well imagine that the atmosphere attains a very high temperature owing 

 to the exposed state of the dry ground ; but a country overrun with 

 forests, as on Dee-side, is kept comparatively cool, partly by the sun's rays 

 being prevented from reaching the earth, and partly by the abundant 

 evaporation which takes place from living vegetables. 



With regard to the statement that temperature is lowered by clouds, 

 Fishermen are generally instructed enough to know that the effect is 

 widely different in certain seasons. By intercepting and throwing back 

 the heat which in winter is so abundantly radiated from the earth's 

 surface, clouds tend to preserve a warm temperature. 



In summer, the earth receives more heat from the sun that the soil 

 radiates, whilst in cloudy weather the access of the caloric rays to the 

 earth is somewhat obstructed, and our planet is protected from a heat too 



