20 Cultivation of the Potatoe. 



But if the potatoes are raised in damp weather, it is better to 

 spread them out on a floor, and let them dry there. 



A point of great importance is to cover heaps over with a 

 layer of straw, at least six inches thick. This layer of straw 

 should be thickest near the ground ; it should there extend 

 beyond the heap of potatoes, so as completely to prevent the 

 access of frost. The straw should be well filled at the sum- 

 mit and angles, and the whole covered up with earth. It is 

 not, indeed, the earth which protects the potatoes from frost ; 

 this effect is produced by the straw, which prevents the radia- 

 tion of heat from them ; but the earth should be closely pressed 

 to prevent the air getting through the straw. Earth -which 

 has no consistence and easily crumbles is, therefore, unfit for 

 the purpose ; if no other can be obtained, some kind of cov- 

 ering must be placed over it. 



A precaution very necessary to be observed, is not to close 

 the heaps completely in autumn so long as the weather con- 

 tinues warm. A small quantity of air must be allowed access 

 .through the top till the frost comes on ; a vent will thus be 

 afforded for vapors which rise from the heap. Covering 

 the heaps with dung is always useless and often mischievous. 



When a thaw comes on it is prudent to open the heaps a 

 little at the top, to permit the escape of vapor. 



