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as far as construction is concerned, only the smaller 

 and closer the structure the more effectual will the 

 process be. The ordinary process is to make up a 

 pit on purpose : this is done by excavating to the 

 depth of five or six feet from the roof at least, and by 

 putting nearly a yard in thickness of fresh manure 

 from the stable-door into it. The pines must not, 

 however, be plunged, but merely set on the top ; and 

 no tan or other surfacing body must be used. They 

 may be crammed here as thick as they can stand to- 

 gether ; and the sides of the pit being pigeon-holed, 

 or walled in some way, rank linings may be applied 

 when the dung from the interior becomes weak. 

 Some caution should be used at first, or if the dung 

 is very new, and from high-fed horses, it may possi- 

 bly overpower them. It would, perhaps, be better 

 to give the manure one sweating before using, and to 

 increase the bulk of such manure as an equivalent for 

 the loss of rankness. During the operation, which 

 may last as long as the dung continues sufficiently 

 warm, a very close and confined atmosphere must be 

 preserved ; especially, we would say, when the very 

 rankest of the gases have passed away, which will be 

 in the course of about a week. The manure will then 

 begin to require water : this will facilitate the produc- 

 tion of a considerable amount of steam or gaseous 

 matter, which is absolutely necessary, in order to pe- 

 netrate every crevice ; in fact, it should, more or less 



