132 Thirty-Fifth Annual Report of the 



wishes can own and run a Babcock and tell himself the truth if 

 he is careful and informed, but not unless he is careful and well 

 informed. 



May market milk be bettered by aught that science has 

 done for dairying, 



Yes, for now are better understood than of old : 



1. The principles underlying stable ventilation and the causes 

 of its failures, 



2. The sources whence are derived the organisms which 

 cavise annoyance, loss of products or disease ; also how to avoid 

 the damage they do. 



3. The dangers of "doping." 



The topic of stable ventilation was to some extent ventilated 

 at the last Montpelier meeting of this association. Since much 

 animal disease is due to housing in ill ventilated stables, it is a 

 dollar and cents proposition to try and better this condition. Too 

 little oxygen and too much carbon dioxide ; too little air, too 

 much exhalation from lungs, skin, manure, etc., are conditions 

 which promote the growth of disease germs and impair vitality. 

 A cow needs hourly 3.542 cubic feet of air. a horse 4,296, or 

 amounts of air which fill a space ten feet high, ten feet wide 

 and 35 toi 43 feet long. Theoretically perfect ventilation is 

 neither practicable nor necessary; but the conditions may be 

 better in many barns. 



Every barn is a problem unto itself, because of differences 

 in shape, distribution of contents, contour of land in its vicinity, 

 relationship to the direction of prevailing winds, number, loca- 

 tion and character of animals, etc. However, some of the prin- 

 ciples which have been worked out are suggestive and helpful. 

 These are : 



1. Entrance of the fresh air near the ceiling of the stable 

 by an indirect line, or by conduit into the barn near the cow's 

 mangers. 



2. Removal of the foul air from points near floor or near 

 ceiling, either exit to be available as needed. 



3. As straight, tall and simple a stack (ventilator) as prac- 

 ticable ; as few angles as may be in side shafts ; no horizontal 

 lines whatsoever. In fact a good ventilating shaft should be as near 

 an approximation to the form of a chimney as is practicable ; 

 should be airtight, should rise high above the roof, be located as 

 near the center of the stable as may be and shoifld have a liberal 

 cross section. It is a good notion to sheathe a metal ventilat- 

 ing flue with wood and to use building paper on a wooden one. 

 A chilled chimney does not draw well ; and the chilling of a 

 barn ventilating flue seriously impairs its efficacy. 



