206 STABLES. 



while the sides are blocked in such a way as to prevent air 

 passing by them. The windows I like best for a stable are 

 those of the louvre pattern, with two or more panes of glass at 

 intervals, say ^ in. between them, so that even when these 

 windows are shut they will admit air, and will also give it an 

 upward direction (Fig. 18). They are of course equally useful 

 in giving exit to air leaving the stable. I thoroughly believe 

 in the correctness of Admiral Rous's remark that " The 

 windows of a stable ought never to be shut by night or day. 

 In cold weather, add to the clothing, but never deprive them 

 of the first great source of vitality fresh air." 



C. By roof ventilation, which may be obtained between the 

 roof and walls ; at the top of the roof ; or by windows in the 

 roof. 



D. By ventilating shafts, which may come out on the side of 

 the roof or on the top of the roof. In the market there are 

 various ventilators for these shafts. Ventilating shafts, as a 

 rule, are needed only when there is an upper storey, against 

 the wall of which they may be placed for economy of room. 



The requirements of the case will decide the question as to 

 the most suitable methods of ventilation. 



Inlets and Outlets for Air. We are unable by any system 

 of natural ventilation to restrict either the entrance or exit of 

 air to particular openings in a building. Thus, if we have 

 an open door on one side and an open window on the 

 other side, we cannot, without employing artificial means 

 for giving a " lead " to the air, make an invariable inlet 

 of the door, and an invariable outlet of the window ; or 

 vice versa. Although the fact that the wind generally blows 

 in a direction more or less parallel to the surface of the 

 ground, gives rise as a rule to an upward draught in the case 

 of a chimney or vertical ventilating shaft ; either of these 

 passages may often serve as an inlet for air, or even as an inlet 

 and an outlet at the same time. It is evident that when this 



