37 



VENTILATION. 



WITH reference to cold and temperate climates, 

 we may define ventilation as the process of 

 removing foul air and substituting pure air 

 for it. In very hot weather, not only is 

 this change of air necessary, but we must 

 also, if posssible, produce currents of air, the 

 velocity of which should be proportionate to 

 the atmospheric heat, so as to utilise the 

 cooling effect of evaporation from the skin. 

 Hence we find that draughts, which are 

 justly regarded in English stables as a 

 frequent cause of disease, are essential to 

 the health of horses, for cooling them down, 



