Barn Construction. 109 



and numerous, but they are never to be opened or 

 used as ventilators. This plan is for the basement. 

 Above, the barn may be built in the usual way with 

 single siding, unless a horse stable, calves or sheep 

 pens are to occupy the upper floor, in which case their 

 quarters should be surrounded with similar walls. 

 Outside walls of such a construction will require no 

 artificial heat in winter to keep the stable warm, a 

 system that is both expensive and needless, and will 

 be as cool as it is possible to have a barn in summer. 

 Eight feet in the clear is enough if properly venti- 

 lated. 



VENTILATION. 



The next great question is that of proper ventila- 

 tion. It has just been said that windows are not to 

 be used summer or winter for ventilation. It is un- 

 necessary, and can be attained more perfectly in 

 other ways. The question is to admit fresh air and 

 to dispel foul air. My method would be as follows: 

 The foul air is of two kinds, the warm air from the 

 animals' bodies, which is lighter than the air and 

 ascends, and the poisonous gases, which are heavier 

 and stay on the floor. We must, therefore, provide 

 an exit for both. The former is easily gotten rid 

 of in the usual way by a ventilator in the floor of 

 the ceiling to a point above the ridge by a wooden 

 shaft surmounted by a cupola. Taking advantage 

 of the fact that the cooler, fresh air is heavier than 

 the heated air of the stable, therefore it best sup- 

 plies the exit of the latter, by coming into the stable 



