496 FARM AND SCHOOL PROBLEMS. 



An investigation of the cost of no silos in the states f,i 

 Illinois, Michigan, Wisconsin and Minnesota shows that the 

 average cost of concrete silos were as follows : 



AVERAGE COST OF ALL SILOS PER TON CAPACITY. 



Monolithic silos $2 . 30 



Block silos 3.10 



PROBLEMS. 



1. What will be the cost of a 150 ton monolithic silo at the price 

 per ton given in the above table? 



2. Find the difference in the cost of two silos of 200 tons each, one 

 is built of cement blocks and the other is built of monolithic walls? 



3. A stave silo 16x32 feet will cost about $300. According to the 

 table on Page 490 what is the cost per ton capacity? 



The deeper the silo, the cheaper it can be built, the capacity 

 in cu. ft. remaining the same; it has been estimated that a silo 

 32 feet deep will hold twice as much as a silo 20 feet deep. 

 Within 5 to 10 feet of the top ensilage will weigh about 30 

 pounds per cubic foot; at a depth of from 10 to 25 feet it will 

 weigh about 35 pounds ; at a depth of from 25 to 30 feet it will 

 weigh 40 pounds and at from 30 to 35 feet the weight is 45 

 pounds. 



Life of The Silo. 



The following statement regarding the average number of 

 years wood will remain without decay is supplied by the Bureau 

 of Forestry, U. S. Department of Agriculture. 



Average number 



of years of 

 Specie. life untreated. 



Cypress 14 



Redwood 14 



Douglas Fir 10 



Yellow Pine 8 



White Pine 8 



The Iowa Silo. 



The Iowa Silos built under direct co-operation of The State 

 Experiment Station at Ames, were built of vitrified Clay building 

 blocks. 



