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BULLETIN" 16, U. S. DEPARTMENT OF AGRICULTURE. 



it is highly desirable that the barn be so arranged as to be fully 

 and freely ventilated, so that it may be possible to steadily remove 

 the warm, moisture-laden air as it becomes saturated. 



In dr} T ing out an ordinary 16-foot or 18-foot barn, holding say 500 

 sticks of cut tobacco, about 5,000 pounds of moisture (water) must 

 be removed. The movement of the air through ventilation is the 

 only means of getting rid of this large amount of moisture. Raising 

 the temperature of the air increases its capacity to absorb moisture 

 and creates a draft, provided means are afforded in the construction 

 of the barn for letting out the air rapidly at the top and for letting 

 it in at the bottom. For the outlet at the top a short lever device at 

 each end of the peak for raising the ridgeboard by means of wires 



Fig. 11. — A good type of flue-curing tobacco barn, showing the ridgepole ventilator 

 raised. The mouth of one of the bottom air inlets is seen just under the open door. 



reaching to the ground, as shown in figure 11, is a handy and simple 

 arrangement. The slit left open when the ridgeboard is raised should 

 be about 5 inches wide. To admit air at the bottom there is always 

 the door, which can be partially opened at will; but this method 

 gives an excess of air immediately in front of and over the door. For 

 an even distribution of the air in all parts of the barn, sewer pipes, 

 about the 4-inch size, set in the wall at appropriate places, will make 

 a good arrangement for the bottom ventilation. The pipes should 

 be set in the wall close to the ground, but just above it on the out- 

 side; they should dip just below the ground on the inside, the open- 

 ings of the different pipes being, respectively, under and near the 

 end and at the middle of each length of flue, including the returns. 

 Each air pipe should be fitted on the outside with a suitable wooden 



