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 



Barn with Automatic Ventilators 



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 in), 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 



