at Home and Abroad. 
203 
(which I am satisfied from experience is sufficient pressure to produce good 
silage) ; but if more is required, it can be applied by screwing down still 
further, as the rods are capable of a strain of over 20 tons each. 
Fig. 8. — End Section of Wooden Silo, 
shaming Press Bods, Springs, dc, 
and how applied to the Cover. 
-Ik 
1-^ 
Fig. 9. — End Section of a Concrete 
or Stone-huilt Silo, with Screw 
Press in operation. 
Fig. 10. — Side Section of Wooden Silo, shmcing Press Bods, Springs, dc, 
and hotc applied to the Cover. 
® 
" Now the cost of pig-iron to weight a similar surface would be at least 
double that amount, without taking into consideration the saving of time 
and labour in applying the screw-press, as compared with the lifting on and 
off of the dead-weicrhts. 
