HARROWING, CULTIVATING 153 



endless variation in the details of construction in 

 each class. 



Shovel-tooth or Coulter Cultivators. Probably 

 more of the cultivators used in this country belong 

 to this class than to any other. The teeth of dif- 

 ferent cultivators vary greatly in shape and size; 

 nearly all enter the ground at an angle and are 

 rounded on the front side. Many coulter culti- 

 vators work up the soil like a plow, lifting, turning 

 and pulverising it to some extent. The soil is 

 loosened to a depth of two to five inches, depending 

 upon the style of cultivator and upon the adjust- 

 ment of the lever with which many coulter culti- 

 vators are provided. The surface of the soil is 

 left either quite level or in rather high ridges, de- 

 pending upon the width of the teeth. The wider 

 they are the rougher they leave the soil. 



Cultivators with about five broad teeth work the 

 ground deeply and are especially valuable for loosen- 

 ing heavy or compact soil; but for the purpose of 

 killing weeds or preserving a mulch, a cultivator 

 with more and narrower teeth is much better. 

 There are too many broad-toothed, deep-working 

 cultivators used and too few narrow-toothed 

 shallow- working tools. Each kind is most useful 

 for a certain definite purpose ; the one for loosening 

 a hard soil, as after planting or after a beating rain; 

 the other for preserving the shallow mulch that is 

 the most useful and economical kind of tillage 

 during the summer. Various attachments accom- 

 pany coulter cultivators, such as wings for hilling 

 or ridging, and rolling disks to cut off strawberry 

 runners. 



Spike-tooth Cultivators. Implements of this 

 class have become very popular in recent years, 

 and deservedly so. The spike-tooth cultivator is 



