FARM BUILDINGS 



339 



It has been found that the minimum circulation of air 

 occurs when the temperature is i5°or2o° above zero on the 

 Fahrenheit scale. A more rapid circulation occurs when 



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Fig. 269. An ideal system for ventilating a one-story barn 



the temperature is either greater or less. As the above 

 table is computed for this temperature, it should be ample 

 under all conditions. 



HOG HOUSE 



Construction. The essentials of hog-house construction 

 are a floor easily kept clean and dry, plenty of direct sun- 

 light, and ventilation to remove the excessive moisture 

 which arises from damp floors and feeding troughs. The 

 expense per pen of a hog house must usually be less than 

 $30 unless more than one litter a year is dropped. The 

 type of roof most common is probably a broken monitor 

 for two rows of pens and a shed roof for one row of pens. 

 The hog-house floor is the one detail upon which there is little 

 common opinion. Concrete is the most desirable except 

 that it is considered by some cold, a disadvantage which 

 may be overcome by the use of an abundance of bedding or 



