24 



THE POLK SYSTEM 



less. If the air gets in, the silage molds and the cattle refuse to 

 eat it. There is enough air for fermentation left in when the silo 

 is filled. Any silo whose material expands or shrinks with heat or 

 cold, wet or dry weather can not keep from developing air and 

 water leaks. Silage that be- 

 comes dry quickly spoils. 



V. THE GOOD SILO MUST 

 BE SMOOTH ON THE INSIDE. Si- 

 lage must be packed tight in 

 order to exclude air. Rough 

 sides, edges, corners and other 

 obstructions to the free set- 

 tling of silage cause imperfect 

 packing and ruin your valuable 



food. 



VI. THE SILO MUST BE VER- 

 MIN PROOF. If the rats can 

 get into your silo they will do 



^so. Build out of something 

 that the rats can not gnaw 

 through. The rat is the fore- 

 runner of too much air and 

 consequently damaged ensilage. 

 CONCRETE THE PERFECT 

 MATERIAL FOR THE SILO 



Recall the foregoing require- 

 ments of a good silo. Read 

 this sentence with them in mind. The monolithic concrete 

 silo is durable, never needs repair, is absolutely fireproof, is 

 air-tight and water-tight, is smooth on the inside and defies the 

 ravages of all vermin. The concrete silo will never warp, rot, 

 crack, burn, leak, blow over, nor waste away. It will never al- 

 low your silage to spoil by freezing, WILL NEVER COST YOU ONE 

 CENT FOR REPAIRS, and will make you quit worrying about fire. 

 Not a single good argument has ever been brought against a prop- 

 erly built concrete silo. No man who has owned one has ever con- 

 sidered the erection of any other kind afterward. 



There is one false objection that is sometimes raised: It is said 



Twin Silos, diameter 16 feet, height 60 feet, near- 

 ing completion. Built by Polk System on Peter 

 Emge farm, Fort Branch, Indiana. 



"They are not built of piece*, and they 

 cannot go to piece*. ' ' 



