TENTH ANNUAL YEAR BOOK— PART X 419 



Furthermore, it is the purpose of the authors to suggest improvements, 

 and to design and develop new types of construction where direct benefit 

 will come therefrom. In presenting in a detailed manner the Iowa silo, 

 it is not intended that it should be recommended above all others. As 

 reliable information as is possible to secure is furnished concerning its 

 merits and faults and, no doubt, many desiring a silo will find the Iowa 

 silo well adapted to their needs.* 



The use of the hollow clay building blocks properly reinforced for silo 

 construction was an idea which came to the junior author during the 

 investigations of silo construction which were carried on previous to the 

 publication of Bulletin 100. Since announcing the design, it has been 

 learned that building blocks in more or less similar form, had previously 

 been used in the construction of silos and the authors have not hesitated 

 in any way to utilize the benefit to be derived from the experiences of 

 others along this line. It is also desired to acknowledge the many valu- 

 able suggestions received from masons who have become interested in this 

 type of construction, block manufacturers, members of the faculty of the 

 Engineering Division of Iowa State College and others. Any suggestion 

 whereby the present design may be improved will be gratefully received. 



LIST OF IOWA SILOS. 



Th following is a list of Iowa silos which have been built during the 

 past two years. With the exception of the first, the experimental silo at 

 Ames, all of these silos were constructed during the summer of 1909. 

 Silos No. 11, 12, and 13, were constructed without the direct co-operation 

 of the Agricultural Engineering Section. Views of several of these silos, 

 numbered as in the following list, are to be found in this bulletin. 



Number. Location. Diameter Height. 



1 Ames, Iowa 16 ft. 30 ft. 



2 Linn Grove, Iowa 16 ft. 35 ft. 



3 Rock Valley, Iowa 16 ft. 35 ft. 



4 Rock Valley, Iowa 16 ft. 37 ft. 



5 Pocahontas, Iowa 18 ft. 36 ft. 



6 Laurens, Iowa 18 ft. 36 ft. 



7 Laurens, Iowa 16 ft. 30 ft. 



8 Rockford, Iowa 18 ft. 35 ft. 



9 and 10 Ottumwa, Iowa 18 ft. 35 ft. 



11 Woodward, Iowa 16 ft. 32 ft. 



12 Clarion, Iowa IG ft. 36 ft. 



13 Hawkeye, Iowa 12 ft. 36 ft. 



*For general Information concerning' silo construction, the reader is referred to 

 Bulletin lOO, of tliis Station, "Modern Silo Construction." Information concern- 

 ing concrete silo construction may be obtained from cement manufacturers or their 

 associations. The construction of a stave silo is described in Circular 130, "How 

 to Build a Stave Silo," Bureau of Animal Industry, U. S. Dcpt. of Agriculture. 

 Silo manufacturers will be glad to furnish information concerning patented silos. 



