130 OHIO EXPERIMENT STATION: MONTHLY BULLETIN 



the time the grove was dusted and, beyond any reasonable doubt, 

 every vestige of foliage would have been consumed had the worms 

 been permitted to continue unchecked. 



ARSENATE OF LEAD POWDER USED 



Because of the distinct limitations in both bulk and weight 

 which accompany the aerial distribution of poisons, the undiluted 

 arsenate of lead powder was used. It is customary in applying the 

 poison in dust form to mix it with lime or some other carrier in 

 proportions varying from 10 to 25 percent of the poison to the 

 dilutant, the reason for this being lodged in the belief that by using 

 a carrier, a two-fold benefit is derived economy of material and 

 evenness of distribution. 



DESCRIPTION OF APPARATUS 



The plane used was a Curtiss JN-6. The hopper for carrying 

 and distributing the powder was attached to the right side of the 

 passenger cockpit, and consisted of an irregularly shaped flat metal 

 box of about 32 gallons capacity sufficient to hold a little more 

 than 100 pounds of arsenate of lead powder. See Fig. 10. At the 

 top was a hinged cover for filling and near the bottom was an aper- 

 ture, 7x9 inches, which could be opened and closed by means of a 

 push and pull rod. Located at the bottom of the hopper was a re- 

 volving vane connected by a sprocket wheel and chain to a crank at 

 the top, which could be operated by hand by a person in the 

 observer's cockpit. When the gate was opened and the liberating 

 mechanism revolved, the powder was released from the bottom of 

 the hopper in an even stream much after the manner that grain is 

 released by a grain drill. 



It will be observed that no blower or fan such as is commonly 

 used in dusting apparatus was used in this machine. The sole 

 requirement of the mechanism was that the powder be released in 

 a steady flow. A glance at the installation, however, will reveal 

 the fact that upon its release from the hopper, the powder was 

 introduced into the "slip stream", the violent air current set up by 

 the moving propeller, and by this tremendous force was thrown out 

 behind the moving plane in a violently swirling mass, which floated 

 out in a beautiful trail to mark the path of the moving plane. As 

 shown by the flying pictures the impetus of this force persisted for 

 several seconds. 



