200 The Sweet Potato 



itself for several hours, getting clogged up with impuri- 

 ties in smoke or fumes. It is unnecessary to fire at 

 night, because the air among the potatoes circulates 

 slowly. The air in the open spaces of the room is 

 dry after a day's firing and diffusion of moisture from 

 among the potatoes in the bins or crates keeps the drying 

 process going on through the night. The process may 

 be lengthened slightly in this way, but no damage seems 

 to result. Whenever spots of dampness are seen on the 

 potatoes or on the walls, ceiling, or stove-pipe (when 

 this is cold), some moisture is present which should be 

 driven out. On the other hand, however, the drying 

 process should not be carried too far. Excess drying 

 will show up in shriveling or other symptoms readily 

 noticeable. 



Extreme care should be taken to operate the house 

 properly during the entire storage period. The follow- 

 ing general rules are given as a guide for this process, 

 which will necessarily have to be supplemented by the 

 judgment of the operator to meet existing conditions in 

 his individual case: 



1. Avoid temperature below 40° E. as potatoes are 

 easily injured by cold( proper temperature can be main- 

 tained by regulating ventilation at doors, windows, and 

 ventilators). Occasionally in exceedingly cold weather 

 a little fire in the stove may become necessary. 



2. Proper ventilation is essential. On bright warm 

 days when the sun is shining, windows, doors, and ven- 

 tilators may be left open ; while in damp rainy weather 

 moisture should be kept out of the house as much as 

 possible by keeping these openings closed. 



3. Keep the house dry. If moisture collects on the 



