at Home and Abroad. 
237 
Englishmen employ horses and men, while Frenchmen add 
draught oxen to their list of treading machines. 
Covering is most generally done by means of boards closely 
fitting together ; but there is here also every divergence of 
practice. Count Roederer and M. de Chezelles both dispense 
with covering as distinct from weighting, but the stones used 
by the former are in no sense a cover as a protection from the 
air, while the earth or sand used by the latter is doubtless very 
efficient in that respect. At the other end of the scale I may 
put Mr. Gibson's elaborate arrangement of dowelled boards, 
the joints covered first by felt and then again by battens ; also 
Lord IVIiddleton's arrangement of a tarpaulin underneath the 
boards, and Mr. Stobart's use of galvanized iron over the joints. 
It does not seem to me necessary to take such extraordinary 
precautions with a view of hermetically sealing the silo. 
I rather lean to the opinion expressed by Mr. Bateman, that 
a means of escape for the gaseous products of fermentation is an 
advantage rather than otherwise. At the same time, I believe 
that this means of escape of gases upwards should not be such 
as to expose any considerable mass of the fodder to the atmos- 
phere. The use of bran or sawdust as a covering to the fodder, 
whether above or beneath the boards, seems, according to my 
observation, to be useless in the first case, and in the second to 
have a pernicious influence in rendering sodden the layer of 
silage immediately beneath it. 
Weighting presents similar divergencies of practice. Between 
40 lbs. and 2 cwts. per square foot is a great gap, so great 
indeed that it is almost impossible to account for it except by 
saying that the lower figure must be too light and the higher 
much too heavy in all cases, while the diminished range then 
left may be explained by differences of circumstances. Some 
of these I will now refer to. The maximum limit of useful 
pressure has been defined by M. Goffart as just too little to 
express any of the juices of the plant. This limit can only be 
determined by experiment and careful observation under dif- 
ferent circumstances. But it is not always easy to make these 
observations, because it is not possible to place a tap at the 
bottom of every silo. Still, there can be no doubt that the 
pressure of 1^ cwt. per square foot, applied by Mr. Stobart to a 
deep mass of cut grass and other green crops, was far in excess 
of necessity, because of the quantity of liquid expressed from the 
silage, and drawn out from the silo. As a general rule, I should 
again say that chopped material requires much less pressure than 
the same material when unchopped ; also that the riper the ma- 
terial, or (to speak more definitely) the less succulent it is, the 
greater the pressure required. Again, the coarser the plant the 
greater pressure necessary ; for instance, tares or peas would 
