PLOWING, SUBSOILING, AND TRENCHING. I49 



as long as possible. It has been found, by actual trial, that, in 

 plowing a field three hundred yards long, a man and team will do 

 one-third more work than in plowing one one hundred yards long 

 — the difference in time being made up in the more frequent 

 turnings required by the shorter furrows. 



In cutting furrows nine inches wide, the time required to plow 

 an acre at the following rates would be — 



Going at the rate of I } miles per hour 7 hours 20 minutes. 



" " " of ij " « « 6 " 30 " 



" " of2| «« " « 4 « 



" " " of 3I " « « 3 " 8 « 



In this table no allowance is made for turnings. 



The distance traveled in plowing an acre is as follows : — 



Width of furrow, 8 inches Distance, I2.\ miles. 



" 9 " " II " 



" 10 " " 9,''n '« 



II " " 9 " 



" la " " 8i " 



SUBSOILING. 



By the term subsoiling, is meant any process which loosens 

 the subsoil without bringing it to the surface. In spade work, it 

 is done by throwing the top spit forward, and loosening, without 

 removing the next spit below. In plowing, the loosening effect 

 is produced by following in the furrow of the surface plow with a 

 subsoil plow^ which passes like a wedge, or like a mole, through the 

 subsoil, allowing it to fall back, in a loosened condition, into its 

 original place. 



There are several forms of this implement. That which is 

 best known being a cast-iron plate shaped very much like the 

 land side and projecting point of the common plow. On the 

 right-hand side, in the place of the mould board, there is a rising 

 flange, or inclined plane, which raises the earth on that side about 

 four inches, (with a slight side thrust). As the plow passes through 

 the ground, the loosened subsoil falls off behind. The tool decs 

 good work, but requires a heavy team. 



A very great improvement on the original form is shown in 



