61 



the leaves are off of the trees, and the same strengtli in winter on 

 apple and cherry to kill the eg-gs of Bryobia. 



The writer witnessed the operation of two excellent power-spraying 

 machines of the character above indicated, built under the direction 

 of Mr. S. A. Pease, for use in San Bernardino County. The work 

 in hand was the spraying of some orange orchards of large trees for 

 the yellow scale {Aspid/ofd.s citrlnus Coq.), and the apparatus worked 

 remarkably well, and the results seem to be most satisfactor3^ In all, 

 nearly 300 acres of orchards have been successfully treated by Mr. 

 Pease. The following description of this apparatus (see PI. I), of 

 which the count}' of San Bernardino keeps three in operation, is 

 supplied by Mr. Pease: 



The San Bernardino County power spraj' machine, built by Osier & Miner, 

 Pomona, Cal., is designed to use either distillate spray or other mixture, and is 

 equijiped with a 2-horsepower Root & Van Dervoort engine, and a double-acting 

 pump with 2-inch cylinders on each end, 10 inches long. The piston of the pump 

 is driven backward and forward by use of bent shaft, with which a large cut gear 

 is placed on the end, run by a pinion on engine shaft. 



The suction of the i>ump is taken from the bottom of the agitator tank and dis- 

 charged into the air tank, which will withstand 800 pounds pressure. The power of 

 the engine is sufficient to run up jiressure of 800 i^ounds or more, and to run four 

 lines of spray hose with two nozzles on each line, which will consume about 250 

 gallons of spray mixture in thirty minutes. The agitator tank is horizontal, holding 

 255 gallons, and has a shaft directly through center in which three sets of paddles 

 are liolted, each being 4 inches in width. The paddles are placed on shaft at 

 different places, and point in different directions. As the paddles revolve they 

 throw the mixture in one direction. There are three lines of breakers placed on 

 the inside of the tank lengthwise, which throw the fluid back, making a double 

 mixture. These paddles are operated i)y means of two sprocket wheels, one placed 

 on end of the bent shaft at engine, and the other on the paddle shafting at the end 

 of the tank, connected by chain. 



There is a small horizontal centrifugal pump run by belt from the engine, which 

 is used together with 25 feet of suction hose to pump water out of ditch or standi)ipe. 

 By this means the agitator tank is filled in four or five minutes. The above appa- 

 ratus is mounted on a platform over a set of iron trucks with 5-inch tires. A pair of 

 bolster springs are used which will carry a weight of 8,500 pounds. 



The methods of supervision of treatment of orchards in California 

 are always instructive. In Los Angeles County there is direct super- 

 vision of the work ])y the horticultural commissioners. The fumiga- 

 tion or spra^'ing is done hy contractors, but with the provision that 

 the Avork must be approved by the proper county official before pay- 

 ment can be collected. At Riverside the work of this sort is done by 

 the county directly, and a charge is made for actual cost, plus 10 per 

 cent. A similar method is followed in San Bernardino County. 



