April, '11] WORSHAM: SPRAYING APPARATUS 193 



fitted with what is known as "extension towers" which consist of 

 tubing from fifteen to twenty feet long, carrying a nozzle at the tip. 

 This method has been used mostly by the United States Government 

 in roadside spraying in the moth-infested area. 



In some cases, it is not possible to secure as good results with the 

 towers as it is with the long nozzle, and this is particularly true when 

 the wind is contrary. 



In calculating the cost of treating shade trees and woodland areas, 

 a reasonable amount must be allowed for depreciation of apparatus. 

 We consider that 20 per cent should be allowed annually on the 

 machines, and 50 per cent on the hose. The average cost of spraying 

 shade trees, both large and small, is between fifteen and twenty cents 

 per tree. 



One other improvement which I neglected to mention, which will 

 be used in this year's machines is the high tension Bosch magnetos 

 instead of batteries for ignition, and mechanical oilers in place of 

 gravity feed. The use of the magnetos will strengthen the power and 

 the oilers will eliminate excess oil in the engine base. 



From our experience the different spraying outfits may be rated as 

 follows: First, the hand pump, agitation not good, expensive to use 

 when much work is to be done; second, small power outfits, not 

 much better than hand sprayers; if the proper agitation is secured 

 too much power is consumed and not enough remains to give efficient 

 results at the nozzle. We find that efficiency and economy must be 

 considered at the same time, and high class outfits, alone, will give 

 these results. 



President Sanderson: The next paper, by Mr. Worsham, who 

 is not here, will be read by the secretary-. 



SPRAYING APPARATUS FOR SCALE INSECTS 



By E. L. Worsham, State Entomologist, Georgia * 



The title of this paper designates a consideration of spraying appara- 

 tus and accessories, particularly with reference to their use in controlhng 

 the Coccidse. Generall^^ speaking, any good modern pump is equally 

 well adapted to spraying both fungicides and insecticides. In certain 

 respects, however, which are primarily concerned with the physical 

 nature of the spray material, the efficiency of the different types of 

 spray pumps is somewhat variable. The reason for this variation is 

 hereinafter discussed more fully under the head of pump construction. 



