STABLES 



73 



Fig. 406. — Double Currents from opposite Windows 



opening by which it entered. The windward side of the ridge opening 



is also presumed to act as an inlet. In the next illustration (fig. 465) 



the windows on opposite sides of the building are shown open. With this 



arrangement the air which rushes in 



at the windward side was observed 



to proceed very much in the same 



way as in the first instance. Some 



of it, however, is driven straight 



across to the leeward window and 



escapes at once. 



Sometimes the movements in- 

 dicated in fig. 465 are disturbed by 

 a backward current suddenly coming in through the outlet window, meet- 

 ing the current which comes from the windward window (fig. 466). The 

 two currents then spread out towards the centre of the stable, strike the 

 ground, and then rise to escape at 

 one side of the ridge. This con- 

 dition is one which, as a matter of 

 course, depends on a change in the 

 direction of the wind, and is, there- 

 fore, only temporary. 



A different set of movements 

 occurs when the opposite windows 

 are half-open in such a way (fig. 467) 

 that the current of air is directed upwards. By this arrangement the 

 entering air is delayed sufficiently long to allow it to mix with the air in 

 the stable before it escapes from the leeward window. It was observed 

 that if the windward window re- 

 mains half-open, and the leeward 

 one fully open, the air escapes from 

 the stables without mixing properly. 



A further change was noticed 

 when the windward windows were 

 half-open and the leeward entirely 

 closed. The current passed upwards 

 to the ceiling, and then descended 

 and mixed with the stable air — the ridge in this case constituted the outlet. 



When all the windows were closed, and the door opened, the ridge 

 appeared to act as a regular outlet; with both the doors and windows shut 

 the ridge openings acted as inlets and outlets, as shown in fig. 468. 



This summary of the description given by Major Fred. Smith will 



Fig. 407 



-Direction taken by Air-currents when opposite 

 Windows are half-open 



Fig. 408. 



-Direction taken by Air-currents when Doors 

 and Windows are closed 



