BULLETIN 6S1, TJ. S. DEPAETMEXT OF AGRICULTURE. 
the left disk in position, and acts as a safety appliance to allow the 
disks to separate in case hard substances pass through the mill. 
L is a quick-release lever for operating the spreading device. 
Figure 2 is a diagrammatic view of the removable hopper (h) 
under the mill, spout' 
(s), single revolving 
damper (installed for 
Series 8 and 9), and 
screw conveyor. The 
bv-pass spout with its 
_f1 f ]\ \ c~\£~~'" ^-^-ay-pass spoor. -L - 1 
fl [ ~T~? \ P\ ^^ valve and peephole 
(C) was installed for 
the purpose of observ- 
ing how far the flame 
due to an explosion 
may be propagated 
without the use of a 
" check" valve. B is 
a peephole for observ- 
ing any flames that 
may pass the damper. 
The construction of the single damper can be seen in figure 3, 
which gives the arrangement when two of these single dampers were 
\ 
Fig. 
-Elevation-attrition mil 
Single clamper. 
/-Foot 
and conveyor. 
J 
Fig. 
-Views of double damper 
placed in series, as in Series 11. As can be -seen in the sectional view, 
the paddles or blades with their rubber "wipers," shown in black, 
are so arranged that there is never a clear path through the damper. 
