No. 4.] GYPSY MOTH APPENDIX. 473 



Nozzles. 



The nozzles principally used are shown on Plate XII, Figs. 1, 

 2 and 3. Fig. 1, the cyclone nozzle, is principally used in spray- 

 ing oil with the cyclone burner. This nozzle gives a perfect spray, 

 and is sufficient in itself where a small amount of spraying is Id 

 be done. Much more work, however, can lie accomplished in the 

 same lime with No. 2, the "Monitor" nozzle, which has four 

 outlets. This nozzle consists of a straight cylinder about three; 

 inches long, with a reducing fitting on tin; lower end, while the 

 opposite end has, in addition to the regular outlet, three side out- 

 lets of the same size. Into each of these four outlets is inserted 

 a cup (Fig. 3c), pierced with two small holes opposite each other. 

 The water entering here is given a rotary motion, like that of the 

 original Riley or the Vermorel nozzle. On top of each of these cups 

 is placed a small disc (Fig. 36) of hardened brass, seven one- 

 thousandths of an inch in thickness. Through the centre of each 

 a small hole is drilled to make an outlet for the water. This disc, 

 being first placed on the cup, is held in position by screwing down 

 the cap (a). The fineness of the spray can be regulated by the 

 size of the hole drilled in the disc. Although the suction pipe 

 of the pump is covered with a fine screen, there is still danger of 

 cloggiug at the nozzle, when glucose or other adhesive materials 

 are used in the mixture. To prevent this, the part (d), which is 

 merely a cylindrical strainer, is inserted at the lower end of the 

 nozzle. This strainer is made of brass wire cloth, and is kept 

 distended by a brass spiral spring (e). It fits tightly into the 

 cylinder of the nozzle, and all the fluid must pass through it. If 

 this screen should become clogged, the nozzle must be taken from 

 the pole and the strainer removed by means of the little handle at 

 the lower end, quickly washed and replaced. 



The Tank and Truck. 



The tank and truck are shown on Plate XII, Fig. 4. Experi- 

 ments having been made with all sorts of tanks, it was decided 

 that wood is the most durable material. The tanks now in use 

 are constructed of one-inch cypress, and have a capacity of one 

 hundred gallons each. The staves being grooved on both edges 

 with a half-round groove, a five-sixteenth-inch, hard-wood dowel 

 is inserted to hold them in position. They are so grooved that room 

 is allowed for shrinking and swelling of the staves and dowels. To 

 guard against shrinkage, the hoops are so arranged that the staves 

 can be drawn together by means of a bolt. Both these devices' 



