38 



No accurate inforniatiou is :it hand as to the difference in power 

 re(iuirod for shreddinj^ and for cutting a certain number of tons of 

 fo(hler corn. It is generally conceded that the shredder head' requires 

 considerable more i:>o\ver and must run at a higher speed than the 

 cutter, but the recent improvements in shredder heads have mate- 

 rially reduced their necessary speed. Machines of great capacity are 

 now on the market shredding as high as 25 tons of fodder per hour. 

 In the better forms of shredders the feed rollers are speeded at about 

 160 revolutions per minute, while the cutter heads are usually run at 

 from 600 to 700 revolutions per minute, and shredder heads at about 

 1,000 revolutions per minute. The ])ower required to rvm the 

 machines is from 12 to 15 horsepower. 



Fig. 20.— Sel£-fee<iing ensilage cutter with blower. 



The ensilage cutters and shredders were at iii'st provided with 

 swivel carriers driven from bottom, which, by means of metal buckets 

 fastened to a chain, elevated the fodder into the silo or mow. Now, 

 however, most of the larger machines are provided with blowers, 

 which consist of a steel fan inclosed in a case, and a galvanized iron 

 pipe usually 10 inches in diameter, extending to the silo or the mow. 

 The fan is sometimes mounted on tbe main shaft of the cutter or shred- 

 der head and is thus driven by the same belt that furnishes power to 

 the machine. The current of air created by the fan forces the fodder 

 into the place desired. For green silage it is necessary to carry the 

 pipe nearly perpendicular to the height of the silo window and to put 

 an elbow on the top to convey the fodder into the silo. The reason 

 for tliis is that when the pipe is perpendicular, or nearly so, the force 

 of the vnnd created by the fan works directly against the force of 



