BRICK AND ALL-METAL SILOS. 



105 



country and that their sales are rapidly increasing, is the best 

 evidence of the entire satisfaction they have given. 



Metal silos are not new. They have been in use in Australia 

 for nearly 20 j'ears. It is claimed for them that they are "wind- 

 proof, fire-proof, crack-proof, shrinkage-proof, vermin-proof, ex- 

 pansion and contraction-proof, collapse-proof, repair-proof; there 

 are no hoops to tighten, no anchors or guy wires to install; they 

 are highly rust-resistant; they are absolutely non-porous, hence 

 are moisture-tight and above all positively air-tight." 



Fig. 45. — Two large Metal Silos and Ohio Cutter at Wagner Bros., 

 Groom, Texas. — Courtesy Perfection Metal Silo Co., Topeka, 

 Kansas. 



The first commercial metal silo, erected in Iowa in 1907, is still 

 giving very satisfactory service. "It was built of interchangeable 

 sections, which were bolted together by means of flanges extend- 

 ing outwardly all around each section. This method of con- 

 struction foriBS a rigid reinforcement of the silo wall, and pro- 

 vides an easy and practical means of increasing the capacity of 

 the silo at any time, by bolting on additional sections to the 

 top. It also makes it practical to move the silo by taking the 

 sections apart and re-erecting them in another location." 



