166 MASSACHUSETTS AGRICULTURE. 



rotate is a spade or paddle, of proper form to penetrate the 

 ground easily. They are hung on one side of each outer tooth, 

 perfectly free to fall out one side, and restrained on the other in 

 a vertical position by the teeth themselves. By this simple 

 arrangement, when the harrow is drawn forward, each revolver 

 will have in front of the teetli on one side a spade five inches in 

 width standing before them, while on the other side they come 

 behind, and therefore lay flat on the ground, offering no resist- 

 ance to the passage of the teeth on that side. The result is a 

 constant rotation. Each spade, as it comes around to the line 

 of draft in front, sets in and obtains its perpendicular at an 

 angle of about forty-five degrees from the line of draft, and there 

 remains stationary, with the exception of a slight twist until the 

 axle passes by and brings it to about the same angle in the rear, 

 when it comes forward edgways about ten inches and slips out 

 on the surface and remains there until it comes round again to 

 the front. A bar, lying across the frame in the rear, gives the 

 means of expansion, six, seven or eight feet for a two-horse har- 

 row. It clears itself from all loose material, and the teeth are 

 prevented from balling by a slot in the spades, which cuts from 

 the teeth everything that tries to catch, leaving the surface 

 remarkably smooth and pulverized with one passage. 



The invention grows out of a necessity for more rapid execu- 

 tion, and avoidance of the hardening effect of a drag-harrow. 

 For it may be mentioned here that notliing will give so hard a 

 tread to a newly-worked road as a few passages of a drag-har- 

 row. Another want was a better chemical condition as well as 

 mechanical arrangement of the soil. By that wonderful wisdom 

 we see in Providence, the soil is made up of antagonistic prin- 

 ciples, in various acids, alkalies and salts, to act upon each other. 

 If the soil remains unbroken, and these things remain long in 

 contact in one position, they become inactive, and the soil mosses 

 over if not very rich. If so, it produces rank and innutritions 

 plants. When the soil is broken, and the particles driven as 

 far as possible from their original connections, and obliged to 

 form new ones, the action is the same in kind, but less in degree. 

 That is seen in putting an acid into an alkali, resulting in the 

 soil in new compositions, and decomposition resulting in the 

 production of plant-food. 



