16 
BULLETIN 1373, U. S. DEPARTMENT OF AGRICULTURE 
space between the garner and the scale hopper with a curtain of cloth, 
which acts as a filter and permits the air to escape while the dust is 
retained in the grain. When such curtains are made of loosely-woven 
cloth, to permit the air to pass through so as not to create a pressure 
within the scale hopper, the light, fine dust escapes and settles on the 
Sca/e 
Vent 
IQ"diom. 
Id" Square 
Mint 
Canras Curfa/rt 
"attached to oar/?er 
extend//?^ down In- 
<5/de of sca/e hopper. 
Fig. 12.— Scale and garner vents 
scale floor. A curtain of canvas or tightly-woven cloth, inclosing the 
space between the garner and scale hopper, and a vent pipe leading 
from this inclosure to the outside of the building, are better. A ver- 
tical pipe extending through the roof creates a slight natural draft, 
so that the light, fine dust which would escape inside the building is 
drawn outside. This vent pipe should be of sufficient diameter (about 
