132 DESTRUCTIVE INSECTS OF VICTORIA: 



attached to a sufficient length of flexible hose to allow it to be intro- 

 duced into the top of the tree. The orifice of the nozzle should be 

 directed at a right angle to the hose, and not in line with it. The jet 

 of spray may thus, by a turn of the wrist, be directed upward or down- 

 ward, and brought into contact with all parts of the foliage and branches, 

 from beneath as well as from the upper side. 



"The Cyclone Nozzle (Fig. 7; 1 profile; 2 plan; 3 section). — 

 A nozzle which answers the above conditions, and is easily attached 

 to any force-pump by means of a rubber tube, is described in the report 

 of the Entomologist {^Report of the Commissioner of Agriculture, 

 U.S.A., for 1881-2, p. 162). It consists of a shallow circular metal 

 chamber, soldered to a short piece of metal tubing as an inlet. The 

 inlet passage penetrates the wall of the chamber tangentially, admitting 

 the fluid eccentrically, and causing it to rotate rapidly in the chamber. 

 The outlet consists of a very small hole drilled in the exact centre of 

 one face of the chamber. The orifice should not be larger than will 

 admit the shaft of an ordinary pin. Through this outlet the fluid is 

 driven perpendicularly to the plane of rotation in the chamber. Its 

 whirling motion disperses it broadly from the orifice, and produces a 

 very fine spray, which may be converted into a cloud of mist by in- 

 creasing the pressure in the pump. The perforated face of the nozzle- 

 chamber is removable for convenience in cleaning the orifice when it 

 clogs. The diameter of the chamber inside need not exceed 

 ■|-inch and its depth |-inch. A nozzle of these dimensions, 

 attached to the aquapult pump, covers 1| square yards of 

 surface at a distance of 4 or 5 feet from the orifice. The amount of 

 dispersion depends somewhat upon the thickness of the perforated face 

 of the chamber. The diameter of the coue of spray may be increased 

 by counter sinkiugthe exit hole and making its edges thin. Three-eighths 

 inch gum tubing is sufficiently large to supply one or a gang of several 

 nozzles ; the tubing must be strengthened with one ply of cloth. In 

 use the end of the hose is supported by being fastened to a light rod of 

 Avood, which forms a handle, by means of which the nozzle may be 

 applied to all parts of the tree. For full-sized trees a rod long enough 

 to reach nearly to their tops must be used. For this purpose a con- 

 venient device may be made by passing the small rubber hose through 

 a hollow bamboo rod of the required length. A three-sixteenth brass 

 tube inserted in a bamboo rod has also been used. 



" Fig. 12 exhibits a complete outfit for treating orange groves with 

 liquid insecticides, from a photograph taken during actual service 

 in the field. This consists of a common pendulum pump inserted in 

 a barrel and mounted upon a cart. The liquid is delivered through 

 two lines of hose, each ending in a cyclone nozzle. The arrangement 

 here shown permits the spraying of two rows of young trees at once, 

 and thus efiects a considerable saving in time. In the same figure is 

 shown an aquapult pump fitted with a cyclone nozzle and a single 

 length (12 feet) of f-inch hose. The pump is inserted in a pail, ready 

 for use as a portable apparatus for one, or preferable for two men." 



