186 THE CULTURE OF FARM CROPS. 



and the successful growth of the crops. The definite and 

 special purpose of the harrow should be to prepare the soil 

 for the seed, leaving the seeding and the covering of the seed 

 to be performed by the seed drill. 



The effects of plowing the soil which have been described, 

 make necessary more effective implements than the kinds 

 of harrows above mentioned. A great improvement was 

 .made when the coulter harrows were introduced. These are 

 provided with sloping cutting teeth which penetrate the 

 plowed ground easily, and cut and consolidate, while they 

 pulverize it, in a more effective manner. The gradual im- 

 provement in this class of harrows has culminated in an im- 

 plement which does the work in a more thorough manner 

 than any other. This is necessarily a combined implement 

 furnished with an iron bar or frame which crushes the clods, 

 and levels the surface; a set of teeth which slope backwards 

 and further break and pulverize the soil; and lastly, a dou- 

 ble coulter which turns over the crushed soil, in the manner 

 of a set of small plows, to a depth of 3 or 4 inches or more, 

 which is easily regulated by tho operator. It may not be 

 out of place to refer to this implement by name as the 

 Acme Pulverizing Harrow, Clod Crusher and Leveler, 

 because this name perfectly well describes not only what the 

 implement does in the soil, but what a harrow should do to 

 effect its purpose in preparing the soil for the growth of 

 crops. 



This purpose and preparation consist in tearing apart the 

 furrow slices; breaking and crushing the clods; cutting up 

 and compacting the soil as far as the plow has penetrated ;. 

 and pulverizing the whole ground; and leaving the surface 

 fine mellow and open for the circulation of air and the ab- 

 sorption of moisture; as well as the reception of the seed. 



From a consideration of previous chapters, and the knowl- 

 edge of the relations of the atmosphere; the various elements 

 of the soil; of heat; of moisture; and the chemical effects 

 and reactions of the various combinations of these, to the 

 growth of plants, it is easily seen of what importance it is 

 that the pulverization of the soil should be as complete and 



