114 



Barn Construction. 



cattle, and on page 113 for a larger number). The 

 forced-air shafts should have shown the damper on 

 the floor the cattle stand upon, where it may also be 



Bam witK AuK>m&t"ic Venh\£s.K)i'S 



regulated by hand by moving an adjustable weight 

 in and out on the damper shown in the floor above. 



A good place for the exit of this carbonic-acid gas 

 out of the barn is from holes along the side of the ma- 

 nure trench behind the cattle, A A (page iii), as it 

 seeks the lowest level. The same ventilator B takes 

 the warm, offensive air from the fresh droppings to the 

 top of the building (as shown). With a large number 



