1911.] PUBLIC DOCUMENT — No. 31. 71 



111 the drawing the nozzle is shown surrounded by a shield, c, 

 which was for the purpose of protecting the point, c. The 

 nozzle as originally constructed was not provided with a shield, 

 being used for some days without it, but with the hard usage 

 which it received we found that the adjustment was likely to be 

 injured. The nozzle was used in connection with a machine 

 giving 250 pounds' pressure, and the spraying mixture was 

 carried through a 1-inch hose. 



This nozzle was used, the past summer, in spraying over 1,000 

 trees, having an average diameter of about 22 inches. Careful 

 estimates made showed that the average amount of arsenate of 

 lead per tree was 1.7 pounds, or about 17 gallons of arsenate of 

 lead in solution. The cost of spraying each tree, including the 

 labor, gasolene and lead, was 55 cents. A smaller number of 

 the same trees were sprayed some years ago at a cost of $1.50 

 ])er tree; but the spraying with the new nozzle and machine was 

 in every way as good, and the cost about two-thirds less per tree, 

 as by the more costly method, which consisted in the use of the 

 Vermorel and other fine-mist nozzles. 



