IS 



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In six cases of different kinds of soils, tlie least 

 difference between the two columns is 13° (in 

 calcarious sand) ; and the greatest difference is 13.95° 

 (in garden earth, blackish gray). Taking the mean 

 of summer temj^erature, this difference is equal to a 

 removal from the latitude of Massachusetts to that of 

 South Carolina. The benefit of this increase in tem- 

 perature is felt in the spring, by bringing the land 

 into good condition to work two or three weeks ear- 

 lier; and also in the fliU, by keeping off the frost two 

 or three weeks later. Crops may be planted earlier, 

 will have, on account of the higher temperature, a 

 more vigorous growth during the summer, and will 

 have ample time to mature in the fall before they 

 can be injured by frost. 



Drains are peculiarly suited to our climate. 



The objection is often made that, though draining 

 has been proved to be indispensable in Great Britain, 

 yet here, on account of our drier climate, it is less 

 needed. This is a false view of the subject. In 

 England the fall, in a single day, of one inch vertical 

 depth of rain is considered remarkable ; while here 

 the fall of three or four inches is not uncommon, and 

 a fall of nearly seven inches has been measured. We 

 need, then, provision for carrying away four times as 

 much surplus water as is provided for in England. 

 Beside this, the humidity of the English climate is 

 such that the evaporation is only about half what it 

 is here. We have seen how heat is lost by evapo- 



