VENTILATION. 29 



pered before reaching the horses. This cold air being 

 heavier than the warm air, witli which it is to commingle and 

 partly replace, should be introduced from an aperture a few 

 feet from the ground or floor. As the object is not only to 

 introduce fresh air, but also to expel the foul air, some exit 

 of ample size should be provided near or in the top of the 

 ceiling. Such stress has been laid upon good ventilation, 

 that the best means of providing for it are now very gen- 

 erally understood, and all modern stables have some provi- 

 sion for establishing a free current of air through the build- 

 ing. In the usual system employed register-like openings 

 are placed near the floor for the admission of fresh air, and a 

 similar but larger opening is provided in a central part of the 

 ceiling or in the wall near the ceiling. The upper ventilator 

 is connected with the external air by a shaft which extends 

 for a few feet above the ridge of the roof and is protected 

 from the inclemency of the weather by either wooden or 

 glass louvre boards. 



Each compartment of the stable should have its own 

 system of ventilation, and when the construction is such that 

 one room is dependent upon another for the admission of 

 fresh air, it should be the coach house with the harness 

 room or vice versa; the stalls should never be ventilated 

 through the harness room or coach house, as the fumes of 

 ammonia are injurious alike to harness and carriages. 



Lieutenant-General Sir F. Fitzwygram, in his book en- 

 titled "Horses and Stables," fourth edition, page 21, thus 

 emphasizes the necessity of providing good ventilation for 

 the stall part of the stable : 



" Ventilation by means of louvre boards, along the ridge of the roof, 

 should be provided in every case, where rooms over the stables do not pre- 



