16 SILOS, ENSILAGE AND SILAGE. 



"Now, air introduces a means of fermentation of the 

 grain, as well as a means of life for insects, while varia- 

 tions of temperature favor the chemical phenomena of 

 which the grain becomes the seat. 



" The underground silo in masonry offers this great 

 advantage over the granary : that of preserving a low and 

 constant temperature ; but it is nob completely inacces- 

 sible to the air, and it is impossible to render it imper- 

 vious to humidity. As a set-off to these two last incon- 

 veniences, Doyere proposed employing metals. His 

 system of construction consisted of some very thin sheets 

 of iron, preserved exteriorly from oxydation by an im- 

 permeable covering, and enveloped in concrete, which 

 sustains the whole weight. The sheet of iron, he says, 

 only plays the part of an impervious and indestructible 

 varnish. It offers, besides, the advantage of supplying 

 holes which can be shut up hermetically. Finally, a 

 silo of 500 hectolitres (1376 bu.), constructed according 

 to this system, at Paris, with a sheet of iron of a mean 

 thickness of 3 millimetres, and made at a cost of 2 1. the 

 cwt. (1 fr. per kilo), has only cost, including the as- 

 phalte covering, 2250 francs (90 1.), or 4 fr. 50c. per 

 hectolitre (1 s. 4 d. per bushel). Therefore it is seen 

 that, instead of being led into error by ruinous experi- 

 ments on the faith of theories, either preconceived, or 

 else deduced from facts wrongly interpreted, it is simply 

 a question of appropriating for our climate the means 

 consecrated by the experience of centuries in all warm 

 countries." * 



Notwithstanding the defective theoretical views, which 

 were in accord with the science of the time, these rec- 

 ords of investigations, made more than thirty years ago, 

 are of interest as showing the value of exact experi- 

 mental methods in their relations to practice. As an 

 outcome of these studies of the essential conditions for 



* Jour. Roy. AKT'I. Soc. 1884 pp. 120-132. 



