EVAPORATION. 273 



ture is very important, and this influence is exerted ia a 

 great measure through the medium of evaporation. 

 Forests are the abodes of dampness. As these are re- 

 moved, the bogs, morasses, &/C, which they contain, are 

 dried up, and no longer give rise to cold and dampness by 

 absorbing heat, and loading with vapor the air which 

 passes over them. Trees prevent heat from penetrating 

 the earth, and thus render a country in which forests 

 abound cooler than one in which they do not. The 

 decayed vegetation, which is constantly accumulating 

 where the ground is covered with forests, presents a for- 

 midable barrier to the heat, which, were it not for this, 

 would penetrate the earth in summer, and be given off to 

 mitigate the severity of winter. The climate of Europe 

 is well known to be much milder than it was 2000 years 

 ago. Roman writers speak of snow-storms and ice as 

 common in their days, in countries, the inhabitants of 

 which would now be almost surprised to see them. Even 

 in New England it is generally thought that the climate 

 has grown sensibly warmer since the country was settled. 

 Whether this amelioration is wholly to be ascribed to the 

 cause which we have mentioned, may perhaps be doubted ; 

 but that the influence of evaporation is great, few will 

 question. So extensively indeed is its influence connected 

 with changes of temperature, and the growth of plants, 

 that whatever tends to throw light on this connexion well 

 deserves the attention of the agriculturist and the philoso- 

 pher. 



DOMESTIC ECONOMY, ETC. 



The avocations of the husbandman, and the employments 

 of domestic life depend, in many instances, on the opera- 

 tion of nature, which we are now considering. It is 

 evaporation, which removes the superfluous moisture 

 from the ground in spring, prepares the new-mown hay 

 for the barn, and makes ready for use the apparel that has 

 tried the cleansing power of water. It is this that seasons 

 the timber of the carpenter, dries the mortar of the mason, 

 and gives permanence to the effects produced by the skill 

 and labor of the painter. The same agent causes some 

 substances to crumble to powder, and others to become 



VOL. i. NO. xt 24* 



