104 



INJURIOUS INSECTS OF 1904. 

 KERO-WATER SPRAYERS. 



These are machines made both in knapsack form, Fig. 112, and 

 to be used with barrel, Fig. 113, possessing a receptacle for kero- 

 sene so connected that every stroke of the pump handle draws some 

 of the oil from the oil tank and it is mechanically mixed with the 

 water, issuing from the nozzle in what we call the "Kero-water 

 spray." This has the advantage over kerosene emulsion in that it 

 eliminates the making of the latter, and hence is a saving of time. 

 It is, of course, cleaner than the emulsion and easier to handle. 

 Ten per cent of oil and 90 per cent of water, or 10 per cent 

 Kero-water, as it is called, is very efifective against many suck- 

 ing insects, and ordinarily does not injure the foliage. A valve 

 and graduated disk on these pumps is supposed to afford an 

 opportunity to obtain 5 per cent, 10 per cent, 20 per cent of 



Fig. 106. — Double Vermorel Nozzle. 



oil and upwards, according to the needs of the operator. Unfortu- 

 nately in all the pumps with which the writer has had experience, the 

 per cent of oil indicated is not always the per cent obtained. Fur- 

 ther, it has been our experience in the field to find that a Kero-water 

 pump which is delivering say 15 per cent Kero-water at one time, may 

 drop to 5 per cent when the water or oil in the receptacles gets low. 

 However, the first of these defects can be overcome by testing, prefer- 

 ably, with a glass graduate, your own machine before it is used, and 

 making memoranda of what the indicated per cents on the disk really 

 are in practice. We found that 5 per cent and 10 per cent could not 

 be relied upon at all, see page ; that 20 per cent really gave 10 



