Attack by Oiling i59 



Barrels fitted with various adjustable spigots 

 are also used, and work fairly well. The ordinary 

 wooden spigot serves for barrels located on the 

 larger streams. 



On the whole, perhaps the most satisfactory 

 drip is one made of a standard garbage can of 

 thirty gallons capacity. A slot % inch by i>^ 

 inch is cut in the side of the can about five inches 

 from the bottom. Into this slot a flat spout about 

 three inches long is soldered, and an ordinary lamp 

 wick inserted and made to project inside and out- 

 side the spout. 



Water is poured into the bottom of the can 

 until it reaches within an inch of the flat spout. 

 Oil is then slowly poured in after previo.us mixing 

 with about five per cent, by volume of larvacide, 

 the latter thinning the oil. The amount of oil 

 flowing from the can is regulated by compressing 

 or prying open the spout until the drip gives the 

 desired number of drops of oil per minute. 



In order to spread, the drops of heavy oil must 

 strike the water surface with considerable force, 

 hence it is best to elevate the drip so that the oil 

 drops at least three feet before striking the surface 

 of the water. On streams having an average width 

 of one to two feet, from ten to twenty drops of 

 oil per minute are applied. The quantity of oil 



