THE * POWERS THAT BE. 175 



* But when a man gives up the spade, the hoe, 

 or the flail, and employs his horse to cultivate or 

 thresh for him, a new direction of applied power 

 takes place. The back-bone of the quadruped is hori- 

 zontal, not perpendicular, to the ground : and the 

 adaptation of the power must be accordingly. The 

 horse cannot lift and press the implement of cultiva- 

 tion, but he can draw it along ; so the spade and the 

 hoe are turned into tools of draught, and are drawn 

 through the soil, raising it with the spiral-wedge- 

 like action of the plough, very damaging to the sub- 

 soil upon which the whole stress and hardening 

 pressure come, but cheap and expeditious compared 

 with the spade, so far as regards the mere inversion, 

 or partial inversion, of the soil ; though doing little 

 towards its cultivation. Again, in threshing, the 

 application of the horse's power must still be hori- 

 zontal, like his figure, and his work be done by 

 lateral pulling. The direction of animal power, in 

 fact, is horizontal: and horizontal draught is the 

 only form in which it can be applied.* 



' But draught is not necessary to cultivation, nor is 



* Except perhaps in the case of a turnspit dog, or a squirrel 

 in its revolving cage, where it is applied to generate circular 

 motion. 



