Construction of Brick Silos, 



401 



into the upper surf aeo of tlio ?tono work in order to guard 

 against cracking the wall by the pressure of the first filling 

 before the mortar has had time to thoroughly season, which 



**>* 



FIG. 199. Shows au all-brick silo with wall 14 inches thick made of three 

 courses of brick, the outer course being set so as to form a 2-inch 

 dead air space as high up as the shoulder. 



does not take place until after five or more months. The 

 method of laying the sections of iron rod in the wall is rep- 

 resented in Fig. 198. 



