MR. COLMAN S ADDRESS. y 



Ing the sod. My own authority is of httle importance in the 

 case though I have for several years practised on this system and 

 been satisfied of its utihty ; but in addition to the testimony of 

 the gentleman referred to, whose opinions are entitled to great 

 respect, you have the experience in its favor of two as eminent 

 farmers as the country has produced, John Lorain of Pennsyl- 

 vania, and Earl Stimson of New York, who have strongly re- 

 commended it. 



The depth of ploughing and the number of ploughings to be 

 given to land are to be determined by circumstances. Plough- 

 ing is too deep when it buries all the richer parts of the soil and 

 brings to the top only a cold and gravelly substance, unless you 

 have manure in such abundance that you can create a new veg- 

 etable surface. Frequent ploughing in heavy and tenacious 

 soils is useful with this caution only that it must not be done 

 when the land is w^et. Frequent ploughing injures light soils 

 by bringing all the vegetable matter contained in them to the 

 surface to be exhausted by the sun and air. Ploughing among 

 growing crops is often useful in time of drought. By some well 

 conducted experiments of John C. Curwen, an accurate observer 

 and intelligent farmer, with glasses contrived for the purpose to 

 ascertain the quantity of evaporation from the land, it was found 

 to amount on the fresh ploughed ground to nine hundred and 

 fifty pounds per hour on the surface of a statute acre, whilst on 

 the ground unbroken, though the glass stood repeatedly for two 

 hours at a time, there was not the least cloud upon it, which 

 proved that no moisture then arose from the earth. The evap- 

 oration f]:om the ploughed land was found to decrease rapidly 

 after the first and second day and ceased after five or six days, 

 depending on the wind and sun. These experiments were 

 carried on for many months. The evaporation after the most 

 abundant rains was not advanced beyond what the earth afforded 

 on being fresh turned up."* 



Few operations of husbandry among us are executed, in gen- 

 eral, in a more slovenly way than ploughing. — The half- 



* Curwen's Hints, p. 273. 



B 



