32 BULLETIN 1243, U. S. DEPARTMENT OF AGRICULTURE, 
The hand sprayer (fig. 14) referred to is a 3-gallon capacity, com- 
pressed-air type, which it is estimated produces from 40 to 65 pounds 
pressure if pumped at intervals of 100 feet of row. 
Fic. 11.—Power sprayer used in experiments against the Mexican bean beetle, showing arrangement 
of nozzles and device for raising the boom. 
The knapsack type of hand bellows duster used is illustrated in 
Figure 15. The power duster used is shown in Figure 16. 
Fic. 12.—Spraying beans for the Mexican bean beetle with a power sprayer, This machine may 
be adapted to spray 8 rows at once, 
EXPLANATION OF TABLES. 
Table 9 gives only the results of the experiments performed with 
the arsenicals commercially available, arranged by experiments 
chronologically. Table 12 gives results of dusting experiments, 
