INSECTS INJURIOUS TO CITRUS FRUITS 617 



has been added and after free oil has ceased to appear on top of the 

 soap, the water is slowly poured in, about 1 quart at a time 

 As previously stated, the only apparatus required to make this 

 formula in a small way is an ordinary galvanized iron pail and a 

 paddle. 



"The foregoing formula may be modified under certain con- 

 ditions, as the quantity of soap will depend largely upon the time 

 consumed in adding the oil and the amount of stirring; the amount 

 of soap being lessened if the stirring be uniform and ample time 

 be taken in the careful preparation. 



If it be desired to make this formula on a large scale, a 300- 

 gallon cylindrical tank may be fitted with paddles, which are 

 attached to a shaft in a vertical position, occupying the center 

 of the tank. The shaft is fitted with a beveled gear on the upper 

 end. A horizontal shaft is then connected with the vertical shaft 

 by means of another beveled gear, while the other end has a 

 pulley to connect with the engine. A series of brakes should be 

 fitted to the sides of the tank to prevent the entire mass from 

 turning around with the paddles. An entire barrel of fish-oil 

 soap may be placed in this tank and the stirring begun at once. 

 Two barrels of oil may then be run into the soap through an 

 inch or IJ-inch hole in the end of the barrel, or the oil may 

 be run out of the bung-hole. After the oil has been added, 

 either one-half or two-thirds of one barrel of water can be added 

 to complete the preparation of the stock solution. In the final 

 spray this should be so diluted as to contain about 1 per cent of 

 oil by adding 1 gallon of the stock solution to 50 gallons of water. 



" It is also highly practicable to fit up a 50-gallon barrel in the 

 same way as described above for the 300-gallon tank. By attaching 

 a crank to the horizontal shaft the mixer can be run by hand instead 

 of by an engine. Such a mixer, designed and used by Mr. J. A. 

 Stevens, De Land, Fla., has been found practicable. The writer 

 has used an ice-cream freezer for making an emulsion, by removing 

 the can and adding a false bottom of 1-inch board to hold up the 

 stirring gears. In fact, many different types of mixers can be 

 constructed, depending on the material available and the scope of 

 the work involved. 



