VENTILATION OF STABLES. 49 



a sufficiency of fresh air, without causing injurious draughts 

 to come in contact with the horses. Free ventilation is 

 greatly promoted by the tendency of heated air to expand 

 and ascend ; so that if an exit be allowed it, towards the 

 roof of the stable, it will escape, and cold air will rush in 

 from below to occupy its place. If it cannot enter below, then 

 it will from above, and cause down draughts. 



The best system of ventilation is that which ensures a 

 uniform supply of cool fresh air by night as by day without 

 causing gusts or draughts, especially upon the legs. But this is 

 not always easy to obtain, and particularly in stables which 

 contain a large number of horses ; small stables are more easily 

 well ventilated. 



Various plans of ventilating have been proposed, but they 

 are all the same in principle, and are based upon the above- 

 mentioned requirements, which may be summed up as escape 

 for vitiated air, and introduction of fresh air without draughts. 

 To ensure this object, it has been recognised that the outlet 

 passages or flues should be more in number, but less, collec- 

 tively, in sectional area, than the inlet ones, the flow of air 

 into the stables not exceeding five feet per second ; so that by 

 having a greater number of outlets than inlets, and these as 

 far as possible from each other, the air on entrance is diffused 

 gently, and draughts avoided. 



In the case of single stables with a loft above, and where 

 the horses stand all one way, it has been recommended to have* 

 a nine-inch earthenware drain pipe carried in the form of 

 a syphon through the rear wall, so as to discharge the supply 

 vertically, at or near the ground level ; while the outlet shafts 

 (one for each three horses), which may be six-inch iron rain- 

 spouts, should be fixed immediately over the stall partitions 

 or bales, on the front wall, the bottoms of the pipes being level 

 with the underside or ceiling of the stable. These pipes should 

 be carried through the loft and the roof, and capped in such a 

 E 



