DUSTING COTTON FROM AIRPLANES. 6 
THE HAND-CRANK HOPPER. 
The type of hopper first constructed is illustrated in Figures 1 
and 2. Figure 1 showing the manner of installation in the plane 
and Figure 2 the hopper as it appeared after removal from the plane. 
For convenience the discharge was arranged through the bottom 
of the fuselage, although later developments indicated that possibly 
this is not the most desirable place. This hopper was constructed of 
galvanized sheet metal and occupied practically half of the space 
in the observer's cockpit, leaving barely room enough for the opera- 
tor to stand and turn the feeder crank. Furthermore, the presence 
of the walking beam for the controls in the front end of the cock- 
pit made it necessary to undercut the bottom of the hopper consider- 
ably. 
Fig. 1. — Curtis plane equipped with hand-crank hopper. Lid of hopper open for filling. 
Outlet for discharging dust shown projecting below fuselage. 
The apparatus consisted of the dust chamber, the outlet or dis- 
charge tube, and the feeding mechanism. A hinged lid was provided 
for filling from the top, and the capacity of the hopper was about 
12,500 cubic inches. The poison used in a majority of the tests was 
the ordinary calcium arsenate sold on the market for boll-weevil 
control, and all references to dusts in the following pages refer to this 
material, unless otherwise stated. As the standard specifications for 
calcium arsenate for boll- weevil control require a volume between 80 
and 100 cubic inches to the pound, and the dust used in these ex- 
periments tested practically 100 cubic inches to the pound, the hopper 
capacity was approximately 125 pounds. 
The outlet or discharge tube at the bottom of the hopper was 
intended merely to carry the dust through the bottom of the fuselage 
and drop it into the air. It was not possible in the preliminary work 
