22 BULLETIN 815, XT. S. DEPARTMENT OF AGRICULTURE. 



with its distributor and which could be sold at a more reasonable 

 price. The only answer to this problem which has been developed so 

 far is the wheel-traction or cart type of duster. 



WHEEL-TRACTION OR CART DUSTERS. 



For the wheel-traction duster a light two- wheel cart is utilized and 

 the power for driving the fan, feeder, etc., is derived from the wheels 

 of the cart. This duster is pulled by two mules and is operated by 

 one man instead of two. By the beginning of 1919 a tentative model 

 had been produced which was placed in the field and operated on a 

 practical basis throughout that season. This machine proved emi- 

 nently satisfactory in spite of the fact that it was very crudely con- 

 structed, and it was selected as the most desirable type for general 

 use in cotton dusting on a large scale. As built, it proved far simpler 

 and easier to operate than the power machines and was especially 

 valuable for its convenience in driving through the field. A number 

 of duster manufacturers became interested in this type of machine 

 and several models based somewhat on this idea are now on the 

 market and others are in the course of construction. These differ 

 widely and embrace the ideas of individual designers, but the general 

 principles of construction are more or less the same. Practically all 

 of the machines are built with an arched axle providing a 42-inch 

 clearance beneath the arch and having a tread of about 48 inches, 

 thus enabling satisfactory operation in any cotton rows not narrower 

 than about 36 inches. 



It has been found that under normal conditions one of these 

 wheel-traction machines will probably average about 25 acres per 

 night of operation. It may exceed this amount under very favorable 

 conditions but it is not safe to figure on a greater average than this. 

 As has been pointed out, it is undoubtedly desirable to provide 

 equipment for treatment at a time interval of about 4 days. Owing 

 to rains and other interruptions, it is undoubtedly not safe to figure 

 on more than three days' operation out of the four. Consequently, 

 about the best that can be expected of one of these machines is that it 

 will handle in the neighborhood of 75 acres of infested cotton 

 throughout the season. 



So far the machines of this type which have been built have been 

 placed on the market at a rather high price, ranging from about 

 $350 to $500. The manufacturers have taken extreme precautions 

 to place the highest quality of workmanship and material in the con- 

 struction and this has resulted in making the price of the machine 

 higher than is generally desirable. It , still remains to be seen 

 whether or not this cost is justified by increased efficiency of the 

 machines. It seems quite probable that other machines built on 



