104 VETERINARY HYGIENE 



perly ventilate any animal building in the absence of an open roof. 

 Though it is true that open ridge ventilation is the ideal method, 

 it is far from being the case that satisfactory ventilation is impos- 

 sible by any other means. 



The most suitable method of ventilating such stables is by the 

 use of windows of the Sherringham type, one being placed at the 

 head of each horse's stall ; the windows on the weather side will act 

 as inlets and those on the lee side solely as outlets, thus producing a 

 cross-ventilation. Where there is no ridge outlet the size of the 

 windows must be increased accordingly. The installation of extrac- 

 tion tubes or shafts as described on a former page should be effected 

 where possible. 



THE KING SYSTEM. This method was evolved by F. H. King 

 in 1889, and is used to a very considerable extent in America.* It 

 consists of two sets of flues one of which provides the fresh air, 

 while the other furnishes an escape for the vitiated air. The 

 following instructions are taken from the official bulletin : The 

 inlet or fresh air flues should be placed in the exterior walls of the 

 building and not more than 10 feet apart ; the greater the number 

 the more effective the ventilation, since they enable the fresh air 

 to displace the foul air more rapidly. The outlet may include 

 one or more flues, but should be so located as to provide the quickest 

 means of removing the foul air. The outlet shaft is carried down 

 to near the floor. The objects of placing the intake of the extraction 

 shaft at such a low level are given as follows: (1) To remove 

 the carbon dioxide and the waste products of the lungs produced 

 by breathing. This foul air settles near the floor and animals are 

 compelled to breathe it with the impurities. (2) To dispose of 

 the cold air in winter weather rather than the warm. The coldest 

 air in a room is at the floor and the warmest at the ceiling. Fresh 

 air is taken in through small flues placed at intervals along the side 

 walls as shown in the figure. The outside opening is placed near 

 the ground line, but may be higher in the wall if found necessary. 

 It should not, however, be placed less than 3 feet below the ceiling 

 to guard against the warm air flowing outward. The inner open- 

 ing of the intake shaft is placed just under the ceiling and may 

 be provided with a movable shutter to control the amount of air 

 passing in. It is pointed out that for this system of ventilation to 

 be successful the ceiling and walls must be practically air-tight. 

 The object of having the air-inlet opening at such a high level is 

 that the incoming air will mingle with the warm air found at the 



* The King System of Ventilation, Univ. Wiscon. Agric. Exp. Station, 

 Bull, 164, 1908. 



