No. 144 J 303 



By simple meaDS, irrigation may be applied on any farm, the 

 expense varying with circumstances. The benefits ensuing will 

 always be great. Ninety-nine hundredths of our farmers, how- 

 ever, if they wish to escape the eliects of long continued drouth, 

 will find their most economical means to be subsoil plowing 

 and under- draining. Many farmers suppose that by opening the 

 soil to the circulation of air they admit a greater amount of heat, 

 and thus dry the earth to a still greater depth, and that under- 

 drains, instead of increasing the amount of water in the soil, will 

 draw it off with greater rapidity. A little reflection, however, 

 suffices to show them that their reasoning is incorrect. Thorough 

 subsoil plowing, accompanied by under- draining on all but very 

 dry lands, will most effectually pulverize the soil to a great 

 depth, and to this thorough disintegration we look for our supply 

 of moisture. 



The manner in which this is deposited is very simple. The 

 soil and the air always contain about the same amount of water. 

 In winter the soil contains more than in summer, when a part of 

 its moisture is removed by heat, and exists in the atmosphere as 

 a vapor. On the dryest day this summer the atmosphere has 

 contained more water than on any other day during the season. 

 Being in tlie form of a vapor, it was of course imperceptible to 

 our observation. 



It was held in the vapory form by heat. When this vapor 

 comes in contact with substances colder than itself, it loses its 

 heat, contracts, and becomes liquid water. We often see that a 

 cold pitcher, in summer, becomes covered with moisture by this 

 condensation of the vapor in the atmosphere. Coal cellars are 

 always damp in summer when the air with its watery vapor is 

 allowed to circulate through them. 



Now, sir, if the same air circulates through the cooler subsoil, 

 its moisture will be deposited by the same principle of condensa- 

 tion, and in this manner the soil may always (in every situation 

 where subsoil plowing and under-draining are possible,) be sup- 

 plied with moisture in sufficient quantities to answer the purpo- 



