486 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



ing and dosing at hourly intervals. An increase in apparatus or men 

 for handling and dosing will naturally admit of an increase in this 

 number. 



Care. — The greatest care should be exercised to prevent acid com- 

 ing in contact with the tents for every contact results in a large or 



Fig. 485. — A cheap and satisfactory hand chemical cart. (Photo by R. S. Vaile) 



small hole. Every day each tent should be carefully examined and 

 all holes covered with seAved patches. Failure to follow these sug- 

 gestions is sure to result in poor and unsatisfactory work. 



CHEMICAL WAGON 



Under the old system of scheduling and estimating, the dosage 

 for every tree was sometimes made up at some central point in the 

 orchard and distributed in carriers by hand. The new system of 

 determining the dosage requires the measuring and weighing at each 

 tree, so that a chemical cart or wagon is needed to carry a full supply 

 of acid, cyanide and water in easily available shape. 



The sulphuric acid should be kept in an earthenware or lead-lined 

 container capable of excluding air on account of the absorption of 

 large quantities of water and drawn off through a rubber siphon or 

 outlet. An ordinary keg or barrel with faucet will hold the water 

 and a tight box is all that is necessary for the cyanide. Dosage 

 schedules, graduates, clamps, rubber gloves, scales and sufficient 

 light complete the outfit. 



FUMIGATING MACHINE 



A special fumigating machine has recently been invented in which 

 the gas is almost instantaneously generated and conducted to the 

 tent by means of a rubber hose. So far the work has been more or 

 less experimental, but it has clearly shown the adaptability and 

 advantages of such a method and promises to greatly modify fumi- 



