Climate. 9 



atmosphere, greatly injure the vegetables over which they 

 extend, and increase the bleakness of the climate in their re- 

 spective neighbourhoods. They likewise occasion great hu- 

 midity in the atmosphere, and too frequent falls of rain. By 

 drainage and cultivation, these pernicious effects, are either 

 wholly removed, or greatly mitigated. 



In bleak and comparatively barren situations, it is highly 

 beneficial to divide the land into small inclosures, with hedges 

 and belts of planting, for the sake of warmth and shelter ( 3 ) ; 

 and were even a part of the heights of a country planted with 

 judgment, the force of the wind would be diminished, its ac- 

 tion divided, and the climate materially softened ( 4 ) ; the be- 

 nefit of which would be felt, not only on the hills, but also, 

 from the shelter arid additional warmth which would thus be 

 given, on the plains below. 



In low and flat situations, on the other hand, every obstruc- 

 tion to a free circulation of the air should be removed, by en- 

 larging inclosures, thinning and clipping hedges, and judi- 

 ciously pruning hedge-row trees. Particular attention ought 

 likewise to be paid, to the important operations of draining 

 the soil. By these means, the climate may be rendered more 

 salubrious, and the fruitfulness of the earth, augmented to a 

 degree, not otherwise to be expected ( 5 ). And, lastly, 



The climate of an extensive region may be much improved, 

 by cutting down large forests, by draining great lakes, by lay- 

 ing dry extensive marshes, and above all, by judicious cultiva- 

 tion. When the surface is broken, water subsides into the 

 soil, instead of either resting on it, or being thrown off in 

 torrents, which are often the source of much mischief; and if 

 the surface is formed into ridges and furrows, the soil is not 

 only enabled to imbibe the salutary rays of the sun, but the 

 drainage of the land, from superfluous water, is greatly facili- 

 tated ( 6 ). These processes, therefore, have the effect of re- 

 gulating moisture, diminishing cold, and accumulating heat ( 7 ). 

 The instances which history furnishes of such improvements, 

 conducted on an extensive scale, and attended by these ad- 

 vantages, are numerous, and well authenticated ; and thence 

 many countries now possess a genial climate, which in former 

 times were scarcely habitable for cold ( 8 ). 



2. Heat. The importance of heat, as a stimulus to ve- 

 getation ( 9 ), cannot be doubted. It is at a certain degree of 

 heat that vegetation commences, and it becomes nearly sta- 

 tionary, when the temperature falls below it. There are, 

 comparatively speaking, but few plants calculated for very 

 cold countries, and these are seldom valuable ; whereas in warm 



