74 BOARD OF AGRICULTURE. 



and its evaporation consequently is as rapid as that from the 

 porous surface, or even more so. 



There can be no greater mistake than to fear to injure the 

 crops by the evaporation gained by mellowing the soil. Plants 

 never suffer so much as when the surface becomes a little hard 

 and forms a thin crust, which cuts off all communication with 

 the air. But when this crust is broken, and the earth is loos- 

 ened, the dews reach the roots of plants, and are often suffi- 

 cient to support vegetation a long time without rain. Let any 

 one who doubts try the experiment, and he will be convinced 

 of the advantage of deep ploughing and frequent loosening of 

 the soil. I am the more anxious to recommend this practice 

 of frequently stirring the surface of cultivated lands, because 

 by means of the cultivator for the larger crops, like Indian 

 corn and potatoes, and the onion weeder, that indispensable 

 labor-saving machine for root crops, it may be done by every 

 farmer with very little expense. 



The question has frequently been raised, whether our climate 

 has undergone any perceptible change within the last two hun- 

 dred years, or since the settlement of the country. The sub- 

 ject was so well treated in a communication to the Board of 

 Agriculture by the Hon. John C. Gray, and published in the 

 Report of last year, that I shall only briefly allude to the present 

 state of the question. Statistics give no good evidence of any 

 material change; but nothing is more common than to hear the 

 remark, that our winters arc not so severe, or that we never 

 have such severe storms, as formerly, while our summers every 

 year become more oppressive; or, in other words, that the cli- 

 mate is warmer than it was. We can hardly believe that an 

 impression which prevails so generally can be entirely without 

 foundation. Besides this, we know that causes have long been 

 in operation which tend to produce the effect in question. 

 These causes have incidentally been alluded to above, and need 

 not be dwelt upon here any further than to say, what has already 

 been intimated, that dense forests must prevent the snow from 

 melting and the moisture from evaporating within their limits, 

 and thus lower the temperature of the atmosphere within them, 

 making, as it were, a reservoir of cold air, from which a con- 

 stant current will be poured upon the surrounding country. In 



