44 



FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



Fi^. 10 is taken from my annual report as United States Entomologist 

 for 1886. It represents a spraying outfit in operation against the Fluted 

 scale {Icerya purchasi), and indicates sufQciently well the use of the lad- 

 der just referred to, and also of the extension poles. 



In Garden and Forest for June 19, 1889, Prof. J. B. Smith, entomol- 

 ogist of the New Jersey experimental station, reports the successful 

 spraying of elm trees in the Eutgers College campus, some of which 

 were over 50 feet high. A Seneca Falls force-pump, provided with 

 some 50 feet of hose, was used. By removing the spraying attachment 

 from the nozzle — a large-size Nixon — the liquid could be thrown in a 

 small stream to a distance of 20 feet. A light ladder gave access to 

 the center of the tree, from which point the extreme tips of the 

 branches could be reached. 



Nozzles. — In any device for applying liquid insecticides the nozzle is 

 of prime importance, for on its efficiency will depend in large degree 

 the success or failure of the work. The desiderata in a spray nozzle, 

 as I have elsewhere stated, are "ready regulation of the volume to be 

 thrown ; greatest atomizing power with least tendency to clog ; facility 

 of cleansing, or ready separation of its component parts; cheapness; 

 simplicity and adjustability to any angle." 



Without attempting a general discussion of the merits of different 

 classes of nozzles, I shall content myself with a brief reference to a few 

 styles, which, to a greater or less degree, answer the conditions just 

 enumerated and which have stood the test of practical work. 



The Riley or cyclone Nozzle. — This nozzle is now so widely known as 

 hardly to require description. As there have been some erroneous state- 

 ments as to its invention, I may take occasion here to reiterate what was 

 recorded in the fourth report of the commission, viz: that it was a devel- 

 opment and outgrowth of my work on the Cotton Worm, the first sug- 

 gestion of the principle being my own and its development resulting 



Fig. 11.— The Riley or cyclone Nozzle. 



from two years' experimentation under my direction and chiefly through 

 the assistance of the late Dr. W, S. Barnard. " Its principal feature con- 

 sists in the inlet through which the liquid is forced being bored tangen- 

 tially through its wall, so as to cause a rapid whirling or centrifugal 



