234 
Report on the Practice of Ensilage, 
fact that is specially illustrated by the cost, dimensions, and 
capacity of M. de Chezelles's silo (see p. 207). 
Whether his silo should be above or below ground, or partly 
above and partly below, or on sloping ground, must be settled 
by each farmer according to his local circumstances or personal 
opinions. Still it may be allowable to say that if I wished to- 
build a silo I should choose the side of ever so slight an eleva- 
tion or depression, and by artificially increasing the elevation, 
as well as by artificially increasing the depression, I should 
contrive to be able to put in the fodder at the top and take it 
out at the bottom. The saving of labour in most cases would 
very soon repay the small cost of excavating and distributing- 
the additional material. 
If the soil is a dead flat, it becomes necessary to choose 
between the other systems ; and then, looking to the advantage 
of using elevating chaff-cutters such as those I have described, it 
seems that a silo entirely above ground is the most preferable, 
except that the roof cannot well be used as a Dutch barn. 
With a silo entirely below ground, and the roof at a sufficient 
height, the double purpose is secured at one cost ; but against 
this has to be put the danger of percolation of water, as in the 
cases of Mr. Hopkins and the Rev. Mr. Ford. 
The materials of construction must, or rather ought to, be 
brick, stone, or concrete, because with the aid of proper mortar 
and an inside layer of cement they can be made impervious to- 
the air. Nevertheless, attempts to construct silos of wood and 
iron are not wanting; and the efforts of INIr. Stocks and of my 
good friend Mr. van der Breggen are described in the fore- 
going pages. Not having seen any such silos opened, I cannot 
state of my own knowledge what proportion of the silage is 
mouldy when it is first exposed to the air ; but I have re- 
peatedly seen, and it is admitted on all hands, that the greatest 
amount of mouldiness in an ordinary silo is found just behind 
the doorway, and just beneath the covering boards. 
A few words as to the roof of the silo are now desirable. It 
will have been remarked that the only uncovered silo which 
I have seen was a complete failure ; and to save space and 
discussion I must ask the admission to be made that a silo- 
without a roof, in our climate, is too risky a venture to be 
practical. Roofs of silos, then, are either movable or fixed. 
When moveable, the eaves are close to the top of the silo wall, 
and are generally constructed of boards or of corrugated iron. 
The Rev. C. H. Ford's roof consists of wooden shutters, those 
of Mr. Edwards and Mr. Bateman of corrugated iron — th& 
former in flat sheets and the latter in curved ones. These three 
may be taken as types. But, as a rule, the roofs of silos are 
