BULLETIN L204, U. S. DEPARTMENT OF AGRICULTURE. 
to stream-line the exposed portion of this tube and thus avoid air 
eddies. The air had a tendency to turn up into the outlet tube, 
and thus interfered with the proper delivery of the dust. The eddies 
created behind the tube tended also to draw the dust upward around 
the fuselage Instead of permitting it to Mow downward. To reduce 
this trouble a slot was cut through the forward side of the outlet 
tube, jusl below the bottom of the fuselage, and a funnel was placed 
over this opening with the neck inclined downward at an angle of 
about 30°. The de- 
livery tube was then 
c]\i away somewhat 
toward the rear, and 
the air blast created 
by the movement of 
the plane blowing 
through this funnel 
helped to break up 
the dust, and blew 
it downward away 
from the fusel age. 
The construction of 
this funnel is shown 
in Figure 2. While 
it was not perfect. 
the idea can be de- 
veloped and probably 
tised to a very good 
advantage in direct- 
ing and breaking up 
the dust cloud. 
The dust -feeding 
mechanism consisted 
of a cut-off valve in 
the bottom of the 
hopper and a four- 
bladed, rotating pad- 
dle wheel. The valve 
was constructed to 
slide in and out un- 
der the | taddle wheel 
and was operated by 
means of a hand lever 
and connecting link. 
The paddle wheel 
revolved by the operator through a pair of sprocket gears 
and a chain leading from the crank gear near the top of the hop- 
per. When the valve was opened and the paddle wheel revolved, 
the dust was carried from the hopper and dropped into the air 
through the outlet tube. 
Because of the limitations presented by the plane, it seemed im- 
possible to overcome certain difficulties encountered with this type 
of feeder. These will be discussed in detail under a later heading. 
I'ii.. •_■ Hand-crank hopper r« ni< »\* ■« t from plain- t<> show 
details of construction. Note particularly the lever ar- 
gement Cor controlling the Bliding rut off valve 
