No. 4.] HARVESTING AND CURING TOBACCO. 79 



Successful eurinu' rt'(|iiircs certain comlitioiis ut" tempera- 

 ture and moisture to enable the leaf to actually cure instead of 

 simply drying out, on the one hand, and to i)revent loss by 

 polg sweat, on the other hand. The practical question is as to 

 how these conditions can be maintained in the baru inde- 

 pendently of the outside weather. 



Use of Aktib^icial Heat. 

 The natural temperatures prevailing during the curing 

 season are ne\cr too high for good curing, and of course they 

 are never so high as to pre^■ent pole sweat. On the other hand, 

 it often happens that it is too cold for satisfactory curing, 

 especially at nights and when the crop is harvested late, so 

 that even if the pole sweat is temporarily checked the tobacco 

 may be spoiled by haying down. Artificial heat is, therefore, 

 the only means of securing at all times the right temiH'rature. 

 The moisture required for good curing is contained in the 

 tobacco itself, and if the outside weather is favorable, the 

 rate of drying can usually be controlled by ventilation. If 

 the temperature is favorable but the air too dry, the remedy is 

 to close the barn tightly, so as to hold the right amount of 

 moisture in the air within. In case of long periods of rain, 

 fog or muggy weather, ventilation alone cannot be of auy 

 benefit. The tobacco will rot if it has reached the critical 

 stage, whether the barn be kept open or closed. The only 

 means of reducing the moisture in the barn is by using arti- 

 ficial heat combined with ventilation. In the first stage of the 

 curing, before the leaf begins to yellow, there is no danger 

 from pole sweat, but if the outside temperature is below 50^, 

 sufficient heat is needed to prevent the tobacco from becoming 

 chille<l ; otherwise it will hay down. Unless the outside 

 weather is very damp, little or no ventilation is needed. The 

 tobacco in this stage will not give off its moisture any faster 

 than it is removed from the surrounding air. After the Ifaf 

 has yellowed, however, the moisture comes to the surface, 

 whether or not it is taken up by the air, so that the tobacco 

 soon becomes soggy. The only practical means of drying the 

 air in the barn is by heating it, and the only way of keeping 

 it dry is to replace it by freshly heated air from the outside 



