SPRAYS AND SPRAYING . 141 



deaux mixture will corrode, are inadmissible. The 

 pump should be easy to clean. 



The nozzle and the pressure determine the character 

 of the spray. The Vermorel type of nozzle is one of 

 the best; it does good work at a low pressure of 50 to 

 60 pounds, but better work at 100 pounds. It does 

 not throw the spray a great distance. The nozzle used 

 should permit of being readily cleaned. 



The agitator may be (i) mechanical or (2) the jet 

 type. The former is generally used and considered 

 more eflBcient, dashers being used in barrel outfits and 

 whirling paddles in large tanks. The jet type returns 

 a stream of solution from the pump to the bottom of 

 the tank. It can be made efficient on power sprayers, 

 but deficiency of power bars their use on hand outfits. 



Tanks. — Cypress, pine, and cedar are used in mak- 

 ing tanks, the first being considered best. Their ca- 

 pacity varies from 50 to 250 gallons. 



Hose. — The hose should withstand a pressure of 125 

 pounds per square inch. Three and four ply are most 

 used. Some prefer five and six ply. Half-inch hose is 

 most commonly used; some prefer three-eighths of an 

 inch. 



Crop-spraying Attachments. — The potato spraying 

 attachment should carry two or more nozzles for each 

 row. These should be capable of being turned up- 

 ward when not in use, to prevent their clogging with 

 sediment while drying. The spray should be thrown 

 upward and sideways, to coat the under surface of the 

 leaves as well as the upper surface. From two to six 

 rows are sprayed at a time (see Frontispiece and Fig. 

 42), and the attachment should fold or turn up to 



