THE WAREHOUSINa OF GRAIN. 133 



machines, the author believes, anywhere to be found. The 

 grain stores attached to the best modern mills erected in 

 this country are now usually built on the " silo " principle ; 

 but it must be remembered that, in the case of mills, the 

 grain is usually stored only for a short time. 



The shafts are constructed in a variety of forms, but the 

 square and the hexagon are the most common. Theoreti- 

 cally the latter requires a less amount of materials ; but the 

 saving is often more than counterbalanced by the increased 

 cost of construction. Brick and wood are the materials 

 usually employed. Wood is, of course, inflammable; but, 

 on the other hand, it is light, is a bad conductor of heat, and 

 is capable of absorbing moisture from the grain. A com- 

 bination of flat iron rings and concrete is also used. The 

 silos are usually made from 12 to 14 feet square and 30 to 

 50 feet high. The base is made of pyramid form, for con- 

 venience of discharging the grain. 



The chief advantages claimed for the " silo " system are 

 that all the space is used, as the silos can be completely 

 filled with grain; that they can be cheaply and readily 

 filled and discharged, and that no turning of the grain by 

 manual labour is necessary. 



The chief claims urged on behalf of " floor " granaries 

 are somewhat as follows : The grain is kept in good condi- 

 tion by means of the stream of air which passes over it 

 from the windows and doors on opposite sides of the 

 building, there being usually a space of from 3 to 4 feet 

 between the grain and the floor above. The grain can be 

 readily inspected from time to time, and samples can be 

 taken. Where grain arrives in bad condition, it can be 

 spread thinly over the floor, and after being thus exposed 

 for some time, and turned over once or twice, it is brought 

 into good condition. When grain comes in a good state, it 



