^(57^ JAPOGS bJAV 69 



Another obiection is that the warmer air of the stable coming m contact 

 with the cold air in the haymow condenses the moisture. The moisture and 

 some of the foul elements of the an- from the stable are deposited on the hay, 

 and is fed again to the cows. 



If any cow in the herd has tuberculosis this may be a very serious matter. 

 The germs of tuberculosis and other diseases have no power of locomotion 

 themselves, but are readily carried on particles of dust. With the right method 

 of ventilation these particles of dust, carrying the disease germs, would be 

 conveyed through the outtake flues out of the barn and into the open air and 

 sunlight, where they quickly perish. 



If the air with its load of germ-carrying dust is taken into the haymow 

 much of the dust with the germs of tuberculosis and other diseases will be 

 deposited in the hay, and being again fed to the cows may have disastrous 

 results in the spreading of disease. 



To provide the immense amount of fresh air required by the cows in the 

 barn, careful provision should be made when planning and building the barn. 

 It IS, however, not difficult with most old barns to install a satisfactory system 

 of ventilation. 



The only practical way in which oxygen can be brought to the cow's 

 nostrils and foul air removed is by correct ventilation, and this requires: 



1 . That there be a continuous change of air in the stable, so that at no 

 time will there be too much air that has been once breathed. Aulhorilies set 

 3'/4% of air once breathed as the limit. 



2. There must be no stagnant spots of foul air at any place in the stable 

 — the pure air must be thoroughly diffused throughout the barn, supplying 

 fresh air to each and every cow. 



3. This complete change of air and its thorough diffusion throughout the 

 barn must be accomplished without excessive loss of heat. 



4. No harmful drafts should strike the cows. 



James Improved Ventilating System 



This problem, to a large degree, has been solved by the James Improved 

 Ventilating System. It must be remembered, however, that the science of 

 ventilation, especially as applied to the dairy barn, is by no means perfect. 

 There are factors affecting ventilation that are not yet well understood, and 

 it is not possible for anyone to guarantee 100 per cent efficiency in all cases. 



In the James Improved System, the principles of ventilation proven neces- 

 sary by scientific investigators in past years are made use of, together with 

 certain improvements developed by Mr. James and his associates. TTie 

 system may be briefly explained as follows : 



Warm air and moist air rise. 



