FACTS RELATING TO SILO CONSTRUCTION. 279 



then cement. Since the materials for concrete silos 

 are only found in certain localities, and since the 

 essential features of construction are the same as in 

 stone silos described later, the building of concrete 

 silos will not be further discussed. 



Brick silos, as the name would indicate, are made 

 of bricks. They have not been extensively tried, 

 it may be, because of the costliness of the material. 

 In northerly latitudes they too would also probably 

 require a lining of boards on the outside to keep out 

 the frost, as is sometimes the case with concrete and 

 stone silos, but the walls could, of course, be made 

 thick enough to protect the silage unless such a 

 method should prove too costly. In some instances 

 stone silos have been lined with bricks and with 

 manifest advantage. This feature of the use of 

 bricks in silo construction will be referred to again. 

 Stone silos are, of course, built of stone and mor- 

 tar. Almost any kind of stone of suitable dimen- 

 sions may be used in their construction. The 

 chief objection to stone silos is their costliness. 

 Notwithstanding, when the wide distribution of 

 stone is considered and when its durability is also 

 taken into account, it would seem to be eminently 

 adapted to the building of silos. In the southern 

 half of the United States the outside lining of wood, 

 which some authorities claim is necessary in the 

 northern states, could certainly be dispensed with. 

 Experience is further demonstrating the fact that 

 stone silos may also be erected in the northern states 

 without the necessity of protecting them with an 

 outer lining of wood. ( See Page 320. ) Stone silos 

 are therefore likely to grow in favor. The mode of 



