18 BULLETIN 748, U. S. DEPARTMENT OF AGRICULTURE. 
two horses. On 48 per cent of the farms a l-man and 3-horse crew 
was used. The crew of one man and two horses predominated in 
Fig. 10.—A crew of one man and six horses operating a spring-tooth harrow. More 
horses are used here than in the average crew. (See Table IX.) 
the Caro and Alma districts, while the 1-man and 3-horse crew was 
in the majority in the Grand Rapids and Ohio districts. 
ROLLING PRACTICE. 
Two general types of rollers were found in these districts; the 
solid smooth drum roller (fig. 11), either steel or wood, and the bar 
Fig. 11.—Rolling with a smooth drum roller. This type crushes clods and leaves a 
smooth surface. 
roller or pulverizer. (fig. 12). Two hundred and thirty-one smooth 
iron, 87 bar, and 18 wood rollers were reported. The average width 
of these implements was about 8 feet. (See Table X.) 
