192 OHIO EXPERIMENT STATION: BULLETIN 332 



man to train the workmen to handle their soHd-stream sprayer, 

 and in the writer's opinion this is the wise plan to follow where the 

 solid-stream type of spraying is being installed. 



On account of the large size of the hose used and the unusual 

 lengths commonly employed, a number of hose bearers should ac- 

 company each rig, the number depending upon the length of the 

 hose. Many times five to eight are employed. 



In general charge of the outfit should be a foreman, who not 

 only looks after the work, but in addition answers questions and 

 watches that pedestrians and vehicles are not soilec. by the spraying 

 material, since the average American passerby has peculiar ideas 

 concerning his rights. For instance, the writer has observed per- 

 sons deliberately walk into a mist of falling spray, or prompted by 

 curiosity, stop their automobiles in the drift from the nozzle, and 

 immediately become violently angry because their clothing or 

 vehicle was soiled. 



An attendant wagon should be provided for carrying the stock 

 of spraying materials and other necessities, and the most convenient 

 arrangement possible should be made for securing the water supply. 



CAS THE AVERAGE MIST SPBATEB BE USED FOE SOLID-STEEAM WOBK? 



Those who have realized the tremendous advantage of the solid- 

 stream type of spraying over the mist type for city work often 

 raise the question as to whether the mist machines may be equipped 

 with solid-stream nozzles and be made to serve. During the spring 

 of 1916 the writer conducted tests to develop information on this 

 point at Wooster, Marietta and Cincinnati, using some of the larger 

 types of the present day mist sprayers for furnishing the power, 

 and a solid-stream nozzle of one-eighth of an inch aperture, such as 

 is used in the New England States. Briefly stated, the results were 

 but moderately satisfactory. A detailed discussion of the mechani- 

 cal phases which the test involved will not be given ; but the main 

 difficulty which became apparent is the fact that the average mist 

 sprayer today is built to maintain continuous pressures not greatly 

 to exceed 200 pounds to the square inch, and the successful opera- 

 tion of a soHd-stream nozzle involves the maintenance of pressures 

 of 300 to 325 pounds per square inch at the pump and the deliver- 

 ance of from 10 to 12 gallons per minute when the one-eighth of an 

 inch solid-stream tip is used. 



While the operators were able to maintain the desired pressure 

 and deliver the required volume of liquid when every part of the 

 machine was in perfect working order, they found that to do so 



