WATER SUPPLY FOR CROPS. 23 



seed WG may roll the surface, and so compact the soil and 

 restore the power of evaporation to the surface, so that the 

 shallow planted seed may be kept moist. After the plant has 

 come up and its roots get hohl of the soil, we must by 

 tillaire loosen the soil, which dries the surface 1)nt at the 

 same time checks the evaporation from the sul)soil. This 

 tillage should be continued as long and as deep as possible 

 without injuring the roots of the growing plants and as 

 often as the surface becomes compacted by rain or other- 

 wise. By such a system, on good land, we can laugh at 

 drouo-ht, unless more protracted than it often is in our 

 climate. ^ 



The CiiAiRMAX. Gentlemen, — Any questions pertinent 

 to the subject which has been presented are invited from the 

 audience. The lecturer is ready to respond* 



Mr. Beebe, of Great Barrington. Deep tilling of the 

 soil does very well where the subsoil is not barren. All the 

 question about ploughing deep or shallow arises from the dif- 

 ference in soils. A great many subsoils are cold and infer- 

 tile. If you stir such soil, you injure the land. The reason 

 why soils are damp that are tilled deep, is because the air 

 circulates through the soil, and the soil being colder than 

 the atmosphere, the cold condenses the moisture. I believe 

 that is the whole secret of it. It is, so flir as my experience 

 goes. 



■ Mr. Pierce. The gentleman has touched upon a point 

 which I meant to have introduced into my lecture ; but all 

 through this paper I have struggled against length. I found 

 that I had attempted too much ; I have had to condense, and 

 I had no time to enter upon this branch of the subject. 

 And, furthermore, when I got through, I made up my mind 

 that the doctrine which the gentleman announces had been 

 so exploded that it was useless to bring it up here. The 

 facts are positively against that theory. In the first place, if 

 what the gentleman says is true, the soil must be colder than 

 the air; but the experiments of Prof. Stockbridge, Prof. 

 Sanborn and Prof. Penhallow, at Houghton Farm, have all 

 demonstrated that, during the summer, with very rare ex- 

 ceptions, the temperature of the soil is higher than that of 



