116 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



gave the inner oil stream a tangential motion, thns forming a cone- 

 shaped spray, npon leaving the aperature, like that from a Vermorel 

 nozzle. Testing the nozzle convinced us that this section was not 

 necessary, and that it might be eliminated and the nozzle cap put 

 directly upon the ends of the two pipes. The end of the inner oil pipe 

 fits into grooves of the nozzle cap so that no connection between the 

 oil and water is possible except after they haA^e left the nozzle. The 

 oil leaves the cap through a central, round, reamed hole, 0.02 inch in 

 diameter. Around this central orifice are tAvo or more holes, each 

 pair being directly opposite each other and opening into the outer 

 water pipe. The holes for the water are reamed so that the streams 

 from them are directed to meet in front of the center of the nozzle 

 the same as in a calla nozzle. Here they come into contact with the 

 straight or cone-shaped oil jet and the Avhole breaks into a fine spray 

 evenly composed of oil and water. It is evident that if the streams 

 leave the nozzle under the same pressure and the apertures be of the 

 same diameter, the spray must then consist of 33^ per cent oil, if there 

 be two water jets and one oil jet ; 20 per cent oil, if there be four water 

 jets, etc. The percentage of oil may, therefore, be readily regulated 

 by having various nozzle caps with a different number of water 

 holes or Avith water holes of various sizes which have been tested to 

 give a greater percentage. 



Several such caps were made and the whole apparatus was given 

 a thorough test by us. Various minor troubles Avere found in its 

 structure Avhicli it Avould require some little time and experiment to 

 eliminate, but our tests shoAved that the apparatus did practically 

 Avhat it Avas designed to do, and that Avith proper mechanical execu- 

 tion, the principles upon AA'hich it was based Avere undoubtedly cor- 

 rect. While its ])erfection Avas under Avay, the Avriter Avas called to 

 Texas. Avhcre circumstances did not permit the completion of the 

 AA'ork, and the DehiAvare station has giA^en it no further attention sinci' 

 that time. 



It is the AA'riter's belief that a nozzle may be perfected along this 

 line, for there is nothing specially ucaa' in the structure of the pump; 

 and that Ave might thus haA'e a perfect mixture of oil and Avater or 

 other mixture, AAhich, if it could be secured, Avould be of the greatest 

 serA'ice against many insects. This nOAV seems to the Avritcn* more of 

 a problem for the pump manufacturer than the entomologist, and 

 our Avork toAvard the solution of the problem is therefore made 

 public at this time. 



A brief discussion of mechanical mixing j^umps folloAved. 

 Mr. J. B. Smith stated tliat good Avork had been done by some of 

 these pumps in certain sections in NeAv Jersey. The general opinion 



