BOLL WEEVIL CONTROL BY USE OF POISON. 25 



The gun should hang naturally so that the nozzle is directed at the 

 tops of the cotton plants without causing any undue strain on the 

 operator in aiming it. 



The capacity of the feeding mechanism should be sufficient to per- 

 mit the use of a delivery of at least 1 pound in 5 minutes at the 

 ordinary rate of cranking. 



The feed should be quickly and positively controlled. Adequate 

 facilities should be provided for lubrication of working parts. 



The fan should create sufficient air current to break up the dust 

 into a cloud and force it to spread over all parts of the plant. 



The gun should be well constructed throughout so that breakage is 

 reduced to a minimum. 



All parts of the gun should be as conveniently accessible as possible 

 for repair or replacement. 



WHEEL-TRACTION OR CART DUSTER. 



The wheel-traction machine should be light enough in weight and 

 draught, to enable an average team to operate it through a full night 

 without undue fatigue. 



There should be sufficient axle clearance to avoid plant injury. 



The tread should be such that it will straddle a row of cotton 

 without running on the adjacent ones and still prevent the machine 

 from being dangerously top-heavy. 



The machine should be properly balanced on the axle to prevent 

 uptilting of the tongue or undue strain on the necks of the team. 



All details of construction should be simple, fool-proof, and dur- 

 able. 



The feed mechanism should be subject to quick and positive regu- 

 lation, varying from a complete cut-off to a maximum delivery of 

 6 pounds in 5 minutes through the three nozzles at the ordinary rate 

 of walking for the team. 



The fan should create sufficient air blast to prevent clogging of the 

 pipes, and to blow the dust throughout the plants under any ordinary 

 weather condition. 



The machine should be provided with suitable lighting equipment. 



The hopper capacity should be sufficient to hold from 30 to 50 

 pounds of calcium arsenate. 



The distributing system should be provided with a positive lift to 

 regulate the height of the nozzles from vertical to horizontal and 

 should also be arranged to fold in conveniently to permit passage 

 through gates. 



The platform should be large enough to accommodate all ma- 

 chinery and the driver and also to carry a barrel of poison. 



