29 



Commission, both for street trees and in the public parks. A st/ni 

 apparatus, however, of such a capacity that a pressure of 75 poiinds 

 per square inch may be gained will enable the operation of four or 

 five lines of hose simultaneously. The rapidity of work will therefore 

 be doubled, and certainly by the use of two such pumps the shade 

 trees of any ordinary city can be gone over with sufficient rapidity to 

 destroy all insects within the required time. A boiler mounted on a 

 truck, the boiler to be complete with all fixtures, smokestack, bonnet, 

 firing tools, springs to the truck, and a pump having a capacity of from 

 10 to 20 gallons a minute connected with the boiler ready for opera- 

 tion, can be purchased for a sum well within $500. This truck should 

 be mounted on wheels with broad tires, for running over sandy roads. 



Fio. 11. — Fall webworm. Suspended larva and section of web — natural size (original). 



Connecting this apparatus with a proper tank cart would be an addi- 

 tional expense, not to exceed $100 for a tank of a capacity of 200 gal- 

 lons. Such an apparatus, furnished with hose and smoothbore nozzles 

 of about one-sixteenth inch in diameter, when discharging under 40 

 pounds pressure from each of several such nozzles, would spray about 

 half a gallon of insecticide mixture per nozzle per minute. 



A strong steam pump, to be used in connection with a small oil- 

 burning boiler, the whole apparatus on a smaller scale than that 

 described above, has been estimated at |275 by a prominent New 

 York firm, delivered on board the cars. 



There is no reason why an old steam fire engine could not be readily 

 arranged for this shade tree spraying work. In one or two instances 

 a steam fire engine has been used for this purpose without modification, 



