214 



SHADE-TREES IN TOWNS AND CITIES 



stream to a mistlike, fan-shaped spray by turning the 

 handle. 



For spraying very large trees, especially elms, the ends 

 of the branches of which are pendulous and impossible for a 



man to reach, nozzles of 

 the jet type are indispen- 

 sable. Such a nozzle, 

 devised by the writer, 

 is shown in Fig. 30, E. 

 It has a bore of about 

 one-sixteenth of an inch. 

 The mixture comes out 

 in a solid jet; but if there 

 is sufficient pressure, the 

 stream is thrown fifteen 

 feet or more from the 

 nozzle and breaks up 

 finely enough so as to 

 cause the spray to ad- 

 here to the foliage. 



It is important that as 

 fine a spray as the com- 

 bination of high pressure 

 and good nozzle will pro- 

 duce should strike the 

 foliage. The finer the 

 spray the better it will 

 adhere to the foliage. A 

 coarse spray rolls off the leaf. Especially when spraying 

 with arsenate of lead or other stomach poisons, the efficacy 

 of which depends upon its adhesiveness to the leaves, the 

 use of a fine spray is necessary to secure the best results. 



.^.D^mj^r 



Fig. 30. — Spray-Nozzles: A and B, types 

 of cyclone nozzles. C and D, types of 

 Vennorei nozzles. E, Jet nozzle. F, 

 Bordeaux nozzle. 



