FARM MACHINERY 221 



cast-iron disks with wedge-shaped treads, spaced about 

 four inches apart and weighing about 100 pounds per 

 foot of width, is perhaps the most satisfactory. This imple- 

 ment not only thoroughly packs the soil beneath the surface 

 but also collects and crushes the clods and leaves the 

 surface slightly rough and covered with a mulch. 



Selecting a Roller. In selecting a roller, the bearings, 

 strength of construction, and weight are the principal fea- 

 tures which should be given consideration after the type 

 of machine has been decided upon. Hard-wood boxes 

 make the most satisfactory bearings. If the ground is 

 uneven, a flexible frame should be chosen, as there will not 

 only be less chance of breakage in the roller but better work 

 will be performed. 



PULVERIZERS 



The name pulverizer is given to a variety of tools. It 

 usually designates certain curved-tooth harrows of the Acme 

 type and also rollers of the 

 cast-iron type. In some 

 localities the disk harrow 

 is referred to as a pulver- 

 izer. It seems, however, 

 that the implement best 

 described by this name Fig. 132. a pulverizer with rake 



•* attached. 



is the one with curved 



spring knives, either with or without a leveling rake. This 

 tool has not become very popular with farmers generally, 

 but it seems to be gaining favor of late. The tendency 

 has been to try to perform the same work by means of 

 the common smoothing harrow. 



The pulverizer does efficient work in producing a fine 

 tilth. It is especially useful in destroying small weeds just 



