196 The Spraying of Plants. 



of 100 pounds. We can produce a spraying pressure of over 

 200 pounds, but is not necessary as it is too big a strain on the 

 hose. I have had three streams going at one time with a 

 water pressure of 100 pounds. 



" We use the McGowen nozzle, it being the most economical 

 and does not use so much of the liquid as some others, and if 

 necessary, can make the spray nothing but a mist. But for elm- 

 tree spraying we use the McGowen straight stream, as the pres- 

 sure is so great that it tears the stream into a good spray for 

 tree spraying." 



Various modifications and improvements have already been 

 suggested for the above, and the time must soon come when 

 some such apparatus will be generally employed for preserving 

 the long-suffering shade trees of our cities from the ravages of 

 insects. The smooth roads will allow the use of heavier and 

 more simple machinery than could be worked in many of our 

 large orchards. The cost of the treatments would be distributed 

 among so many, and the benefits derived would be so great, 

 that such outfits may soon come into general use. 



Gas engines have also been employed. During 1895, W. 

 R. Gunnis, of San Diego County, Cal., applied kerosene emul- 

 sion to his trees, using power of this nature. " The appa- 

 ratus is placed on the platform of a light wagon, and on the 

 front end is a tank of a capacity of 100 gallons, filled with the 

 emulsion. A small electro-vapor engine on the wagon operates 

 a double-action, high-pressure, cylinder pump, and to this eight 

 lines of hose may be attached. The pump can be worked at a 

 pressure of 200 pounds, rendering the spray fine and strong, 

 and capable of reaching to the tops of the tallest trees, where 

 the hose is supported by ten-foot bamboo canes. Twenty-five 

 or thirty acres of four-year old trees may be sprayed in one day 

 with the labor of four men." 1 



A device for mixing kerosene and water has been invented 

 by Professor Goff, and during 1894 the Nixon Nozzle & 

 Machine Co. offered it for sale in connection with the " Climax " 

 pump, and other firms attached it in a modified form to knap- 

 sack sprayers. Experiments for obtaining such a mixture had 

 been made in 1888, 2 but it was not until about the year 1893 



i Insect Life, 1S95, vii. No. 5, 413. 



Goff, N. Y. State Agrio. Exp, Sta. Ann. Kept, 1888, 148. 



