SPRAY NOZZLE FOR OIL WITH WATER, ETC. 113 



pipe exteiisiou rods, etc. Altogether many hiiiulied in(li\"idual tests 

 were made, and the total result of the work tended to show that 

 none of the pumps could be relied upon to give uniformly the 

 percentage of oil desired. A detailed discussion of the mechanical 

 faults of these i3umps is not necessary at this time, but it may be 

 stated that those pumps made Avith but a single pump drawing from 

 the barrel and oil tank at once were found entirely unreliable, whereas 

 those having two pumps, one in the oil and one in the water tank, 

 and the percentage of oil regulated l)y the length of the stroke of the 

 pumps, were found much more reliable, although in nuiny cases they 

 failed to deliver the proper percentages at the pump before the liquids 

 mixed. In none of this type, even with the double-extension rod 

 having an imier tube conveying the oil to the nozzle, was the unequal 

 mixing of the oil and water in the hose and extension rod wholly 

 prevented, so that variable j^ercentages frequently occurred. The 

 results of this Avork were never i^ublished, but the records exist in 

 support of the above summary. 



It soon became apparent that to eliminate the mixing of the oil 

 and water in the hose and pipe before reaching the nozzle, some form 

 of nozzle must be devised which would mix the two liquids as they 

 left it. Such a nozzle was therefore devised and a working model 

 was made by Queen & Co., a drawing of which was made by them 

 as shown in fig. 6. In the Thirteenth Report of the Delaware Agri- 

 cultural Exi)eriment Station (1901, p. 19G) the writer made mention 

 of this nozzle as follows: "We have had a nozzle made according 

 to plans originated by us whiqh it is trusted will prove more satis- 

 factory in making a uniform mixture of a given percentage of oil 

 and water."' 



In liis recent bulletin upon the San Jose scale," Mr. C. L. Marlatt 

 remarks concerning the oil and water mixture, as follows: 



The best outlook for good apparatus of tliis sort seems to !>(> in carryiiifj; the 

 oil and water in separate lines of hose to the nozzle, unitiui; thcni in the latter, 

 and in niaintainin,sr an absolute eiiuality of i)ressure on both nil and water 

 tanks I)y employing compressed air as the motive force, kept up Iiy an air iiumj). 

 the air chamber connnunicating with both of the liquid receptacles. * * * 

 One or more manufacturers are now working on an apparatus of this 

 description. 



Tliis so closely describes the system originated by the writer in 

 11)01 that it seemed wise to make a record of our woi-k along this 

 line in the proceedings of this association, as the writer was not 

 aware that any manufacturers had taken up the idea or indeed that 

 it had attracted any attention, though we had described the appa- 

 ratus to several entomologists in a general way. 



« Bulletin 62, Bureau of Entomology, U. S. Dept. of Agriculture, p. 77. 

 7487— No. 67—07 S 



