317 



circular in shape, and not more than six inches in 

 width by three inches in height at the centre. The 

 upper portion of the semi-circular cone should project 

 two inches over its base, in order to prevent the 



Front View. Side View. 



Fig 48. — Zinc Venilator. 

 A A, Projecting Cone; R R, Roof; F, Part beneath Roof Slates. 



entrance of rain or snow. (Fig-. 48.) By this arrange- 

 ment cross winds are prevented from beating back the 

 vitiated air, as one side of the roof will always be 

 favourable to its escape. 



CUBIC AIR-SPACE. 



Stables should be built so that each horse has at 

 least one thousand cubic feet of free-air space, and if 

 twelve hundred can be obtained, so much the better. 

 Of course, it must be understood that a large amount 

 of air-space does not cancel the necessity of ventilation. 

 A small air-space naturally becomes sooner foul than a 

 large air-space, but both require ventilation. The 



