DUSTING MACHINES 99 
Dusting Apparatus 
Various types of machines are obtainable for applying insecticides 
in powder form. Most of these are designed to be carried by hand, and 
rapid work can be done with them under suitable conditions. They are 
not so well adapted to applying materials to trees, nor to situations 
that are difficult to reach because of thick, intervening foliage — as, 
for example, in treating 
vineyards. But for use on 
truck or field crops, espe- 
cially in the application 
of powdered arsenate of 
lead, they have a growing 
utility. In the more de- 
sirable types a constant 
stream of air is maintained 
by a rotary fan, and the 
Fig. 64.— A geared powder gun. Original. 
powder may be directed through one or more outlets as desired. The 
amount of material delivered may also be regulated. 
For dusting field crops a simple device is in use in the South, consist- 
ing of a pole 4 to § feet long, to which are tacked cloth bags at 
proper intervals, according to the distance between rows. A hole 
bored through the pole above the bag provides a means of filling it. 
Often the pole is set across a horse’s back, the jarring being sufficient to 
sift the poison through the cloth. 
