^<5/^ JAPQGS bJAV 73 



The air at the ceiling being warmest, the fresh air is gradually warmed 

 as it descends. 



Where the cows face out, air enters from the side wall near the ceiling; 

 where the cows face in, the air is brought to the center of the barn and enters 

 the stable through the ceiling. 



Thus the fresh air always reaches the cows' noses before passing over the 

 gutter, the intakes being so located that the foul air is drawn out from the 

 rear of the cows. See page 54, 55, 58 and 59. 



This principle is a James idea. 



By the proper spacing of the intakes and the correct location of the out- 

 takes fresh air is so thoroughly diffused before reaching the cows that no harm 

 ful drafts are created, as often occurs when opened windows are used for 

 ventilation. 



There are many details, however, that must be observed in order that the 

 system be fully efficient. 



Essentials for the success of the system are covered in the following 

 paragraphs : 



1 . The barn walls and ceiling should be as nearly air-tight as possible, 

 consistent with economy ; they should also be good non-conductors of heat. 



2. The air should be made to enter and leave only through the flues 

 designed and arranged for that purpose; m order that the heat lost may assist in 

 ventilating the barn, haychutes, stairways and other openings should be kept 

 closed. 



3. The flues through which the foul air is taken from the barn should be 

 of a warm, air-tight construction, so protected as not to hinder the draft by 

 allowing the outgoing air to cool too rapidly. The foul air flues should be at 

 least twenty-five feet in height; the opening into the flue being about one foot 

 from the floor, in order that the coldest air may be removed, and with an open- 

 ing of like size at the ceiling for the removal of moist air, should moisture at 

 any time become excessive. These outtake flues should be as straight as pos- 

 sible, with the proper capacity to insure a sufficiently rapid change of air. 

 Outtake flues built on the outside of the barn are unsatisfactory. 



4. The fresh air flues, to be most effective should be air-tight, having 

 their inlets outside of the barn, about midway between floor and ceiling and 

 their openings into the stable within eight inches of the ceiling when the stalls 

 face out. Fresh air intakes should be not more than twelve or fourteen feet 

 apart, and should have a joint capacity exceeding that of the foul air outtakes. 



5. If the cows face the center of the barn, the fresh air should enter the 

 stable through the ceiling at the center through pairs of registers — one for each 

 side of the barn — the registers in each pair being separated. If the cows face 



