IO2 THE FIRST BOOK OF FARMING 



desired to leave the land in a bare fall or winter 

 fallow. At other times of the year the lumps of 

 earth are apt to dry out and become hard and diffi- 

 cult to break. If there is but one work team on the 

 farm it is a good plan during the plowing season to 

 stop the plow in time to harrow the day's plowing 

 before the day's work ends. 



HARROWS 



There are several types of harrows in use. They 

 may be classified according to the style of their 

 teeth or cutting parts ; they are as follows : 



Rolling cutter harrows. 



Spring-toothed harrows. 



Spike-toothed harrows. 



Coulter-toothed harrows. 



Chain harrows. 



Brush harrows. 



Plank or drag harrows. 



These types vary in the depth to which they cut, 

 and the degree to which they pulverize the soil. 



Rolling cutter harrows. Harrows of this type 

 (see Fig. 54) consist of one or more revolving 

 shafts on which are arranged a number of concave 

 disks. These disks are either entire, notched, or 

 made of several pieces fastened together. Examples 

 of these are the disk, cutaway and spading harrows. 

 These harrows cut and move the soil deeper than the 

 other types. They are especially adapted to work 

 on heavy clay soils. 



