THE POLK SYSTEM 



13 



about ten years ago. They go straight to dizzy heights with 

 seemingly little attention to the laws of equilibrium; they bridge 



spans with no at- 

 t e n t i o n to the 

 laws of gravity. 

 Concrete means 

 just as much to 

 the farmerp f; as 

 the same -rapid 

 stride s that 

 characterize the 

 engineering field 

 are being made 

 proportionate- 

 ly of course, on 

 the farm. Prin- 

 ciples of conser- 

 vation and per- 

 manence are be- 

 ing adopted in 

 the agricultural 

 field just as as- 

 suredly as they 

 are in the engi- 

 neering fi e 1 d . 



i.. i6xio feet, capacity Concrete is more 



Built by Polk System |>flB J flr^n permanent; 



-m> Strength -is 

 cumulative?* A^oncrete silo will be stronger 5 ten J^ars hence tKan 

 it is now and "s'tiW stronger when your great-great-grandchildren 

 are ready to use it. Concrete annihilates two words " 



and ".vpmrs." 



S. 



C. M. Saxby's Concrete Silo, Freeport, 111. 

 180 tc 



"They are not built of piece* and they 

 cannot go to pieces. ' ' 



