at Home and Abroad. 
197 
— the latter being in this case to save unnecessary forking until the stack 
has risen. I may here mention that, though I did not fill up the interstices 
between the boards (which I could easily have done), the silage was just as 
free from mould as at any other part of the wall sides ; and further, it may 
be mentioned that when the pressure was first applied from above, the air 
could be heard hissing out through these spaces. 
Fig. 3. — External View of Mr. Johnson's new Silo. 
Wlien the day's filling is complete, the top covering of boards (g, Fig. 4) is 
laid on with longitudinal and transverse timbers (h) to receive the pressure ; 
the hydraulic jack (i), which it may be seen is at the weighted end of the 
lever, then comes into play, and lowers the wrought-iron cradle and transverse 
timbers, which are attached by chains to the lever beam on to the longitudinal 
timbers ; and a strong round iron bolt (k) is then adjusted into one of the holes 
in the cradle according to the height of the silage. The whole force of the 
weight of the boxes full of stones at the out end of the lever, which is about 
four and a half tons multiplied by the length of the lever, then comes on 
and inflicts a pressure of about 2 cwt. per square foot (including the weight 
of the beam, cradle, boards, and everything) ; this at once presses down the 
grass about 2 feet, which is the extent of travel the lever gives at the point of 
