INSECTICIDES AND THEIR USES 



45 



in commercial operations. In spraying several acres of can- 

 taloupes once the writer was surprised to find that a man with 

 a knapsack outfit could do the work at the same price as an 

 outfit consisting of a barrel mounted on a sled drawn by a horse 

 and operated by three men, one to pump and drive and two to 

 carry the nozzles. The latter outfit, 

 however, got over the ground so much 

 more rapidly and saved so much time 

 that it was mainly used. The objec- 

 tions to the knapsack pumps are 

 numerous. It is hard to get the re- 

 quired pressure in the pump on account 

 of its small size and instability. It is 

 rather heavy to carry on the back and 

 is very liable to leak, and the oper- 

 ator who can handle one all day with- 

 out getting his back wet and some of 

 the liquid down his neck is fortunate. 

 As a rule, the low pressure obtained 

 by the knapsack pump results in an 

 inferior job of spraying, though with 

 a strictly first-class vermorel nozzle this is not necessarily so. 



Bucket pumps. — Good hand bucket spray pumps of about the 

 type shown in figure 23 may be had at from $6 to $7.50. They 

 are of great value in the preparation of kerosene emulsion, 

 which, as has already been stated (p. 36), should be applied as 

 a fine mist-like spray. They may be used with ordinary or 

 special buckets and a longer hose than figured (fig. 23) and 

 may be necessary. 



Barrel spray pumps. — These are the largest force pumps and 

 useful both for the field and orchard. They are mounted on 

 barrels or tanks and drawn for field and garden use on wheels, 

 so geared as to straddle rows of vegetables, or a narrow sled 

 may be made to serve the same purpose. A serviceable sled may 



Fig. 23.— Hand bucket pump 



