BRICK SILOS. 105 



Brick Silos. In constructing a brick silo it will be well 

 to guard the following points; Make the foundation of 

 stone if practicable, and let the first course of brick come 

 flush on the inside with the stone work. Bed a five-eighths 

 inch iron hoop in the stone work in the upper part before 

 laying the brick, in order to keep the pressure of brick 

 from spreading the wall before the mortar becomes set and 

 hard. Make a two-inch air space in the walls up to within 

 one-third of the top. This will make a 14-inch wall of 

 three courses of brick. If, however, the silo is to be over 

 24 feet inside diameter, then a four-brick wall is really nec- 

 essary one-third the way up, then the next third of three 

 bricks and the last third of two bricks. The air space 

 should be in the outer part of the wall. Iron tie rods 

 should also be laid around in the wall between the doors, 

 as recommended in the stone work. It is also important 

 that the brick should be wet when laid, otherwise the 

 mortar in which they are laid will be dried out too rapidly. 

 The walls should be plastered over very smoothly with a 

 coat of rich cement, one-fourth to one-half inch thick, 

 and then every two or three years this should be well 

 white-washed with thin cement, to keep the wall protected 

 from the effects of acid in the silage. King recommends 

 that the floor jambs be made of 3x6's or 3x8's, rabbetted 

 two inches deep to receive the door on the inside. The 

 center of the jambs outside should be grooved and a 

 tongue inserted projecting three-fourths of an inch out- 

 ward to set back into the mortar, and thus secure a 

 thoroughly air-tight joint between wall and jamb. The 

 doors may be made of two layers of matched flooring with 

 tarred paper between, and lag screw bolted to the jamb, 

 B as to give a perfect smooth face next to the silage. 



Stone Silos. The stone should have a wall about two 

 feet thick below the surface of the ground, and this may 

 be laid in the cheaper grades of cement. Above the sur- 

 face a good grade of Portland cement should be used. A 

 thickness of wall of 18 inches at the surface of the 

 ground is desirable, but this may be gradually reduced 



