1908.] PUBLIC DOCUMENT- -No.' 73. 151 



Cost. 



4 climbers, 6^ days, . $2 25 $58 50 



5 men, 6-i- days, . 2 00 05 00 

 425 pounds arsenate of lead, . . 12 51 00 



Total, . $174 50 



Average cost of treatment, 9.7 cents per tree. 



LEXINGTON, JULY 3, 1907. 



The woodland along each side of a badly infested road was treated 

 to a depth of 150 feet. All told, 3 acres of mixed growth, ranging from 

 20 to 60 feet in height, and 1 acre of underbrush not included in the area 

 covered by the trees, were sprayed in one hour's time by employees of 

 the United States Department of Agriculture. Arsenate of lead was 

 used, at the rate of 10 pounds to 100 gallons of water. 



Outfit. 



A 7 horse-power Olds gasoline engine, with double-acting pump, was 

 supplied by a 600-gallon tank mounted on a substantial truck. A single 

 line of l^/o-inch hose and a y-'mch nozzle applied spray under a pres- 

 sure ranging from 150 to 175 pounds. 



Cost. 



1 engineer, -J- clay, . . $2 80 $0 35 



7 men, $ day, '. 2 00 1 75 



1 team and driver, f day, . 5 00 63 



1 supply team and driver, % day, 3 00 



60 pounds arsenate of lead, . 6 60 



Gasoline, ... 10 



Oil, grease and waste, ..... . 01 



Total, . $9 82 



Average cost of treatment, $2.46 per acre, or 3 cents per tree. 



CHELMSFORD, JULY 3, 1907. 



The spraying on this date consisted in treating a strip of shade trees 

 and sprout land where gypsy moth caterpillars had been found in con- 

 siderable numbers. The trees were mainly oak, ranging from 50 to 55 

 feet high, with a few pines and birches. Two men were used on the 

 pump, while the driver assisted in the spraying operations. All told, 36 

 large trees and about % acre of brush land were treated. 



Outfit. 



A Friend pump, mounted on a ban-el, supplied two lines of i/2-inch 

 hose equipped with Verrnorel nozzles. Disparene was used, at the rate 

 of 12 pounds per 100 gallons; and 50 per cent, of the trees were 

 . climbed. 



