336 ENGINEERING ON THE FARM 



room is obtained by development of the L, T, and H shapes. 

 A horse barn must necessarily be a little wider than a dairy 

 barn. A general-purpose barn need not be much wider 

 than a dairy barn. A feed and sale barn for either horses 

 or cows is usually 4 to 8 feet wider than a farm barn, the 

 extra width providing for the convenience of purchasers in 

 viewing the stock offered for sale. The round, six- and 

 eight-sided barns are limited to 36 feet in diameter when 

 no silo is built in the center, and to 50 feet with the silo. 

 Diameters greater than this leave in the center of the barn 

 too large an area which is dark and undesirable stable space. 



The general-purpose barn usually provides for all kinds 

 of stock, together with hay and grain for feeding. It is a 

 big unit, but makes winter feeding much more convenient 

 than when the feed is stored in separate buildings at some 

 distance. One ton of hay occupies about 512 cubic feet 

 loose and about 25 cubic feet baled. Straw occupies about 

 650 cubic feet per ton loose. 



Barn ventilation. The motive power of air currents in 

 barn ventilation is limited and uncertain, and it is neces- 

 sary in the planning and installation of a ventilating sys- 

 tem that unfavorable conditions be provided for. Such a 

 measure is the choking of oversized inlets and outlets by 

 means of dampers when the weather is cold and the wind 

 high. Inlets need not be so large as outlets, since there is 

 a large percentage of leakage around windows and doors 

 and through walls. Dairy barns built with double insulated 

 walls and storm windows will be found to require a 

 greater circulation of air to remove the moisture than is 

 actually necessary to secure the required degree of air 

 purity for breathing. This moisture comes from two 

 sources: from the body of the animal and from the water 

 used for flushing concrete gutters and that in mangers for 

 drinking purposes. If too much air is admitted in cold 

 climates, the inside temperature becomes too low. The 

 desirable temperature has not been definitely determined, 



