PREFACE. 



In this volume the author has attempted to bring 

 together everything of value pertaining to the latest 

 concrete silo construction. His investigation of the 

 subject has led him to believe that there is a demand 

 for such a book. While there is a large mass of 

 literature on concrete silos extant, practically every 

 piece of such printed matter is prepared with special 

 emphasis on some particular type of construction, or on 

 some particular phase of the subject. 



This volume is an attempt to bring together all the 

 best things in this scattered literature, making it, so 

 far as possible, a complete compendium of concrete silo 

 construction. For this purpose the author has drawn 

 freely upon bulletins of the various cement companies 

 and of the Association of American Portland Cement 

 Manufacturers, as well as upon publications of the 

 State Agricultural Experimental Stations, and the 

 literature of the companies promoting various patented 

 systems. 



The demand for the book, even before it has 

 appeared from the press, has been so gratifying that it 

 is expected another edition will be necessary at an 

 early date. The author will therefore be pleased to 

 have readers advise him of any errors, inaccuracies, or 

 omissions which they find. 



E. S. HANSON. 

 Chicago, Oct. 15, 1915. 



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