SWEET-POTATO 439 



spot, the soil is excavated to a depth of six or more inches, 

 and a simple frame made with side and end boards : a 

 layer of moist stable manure, with a depth of four to eight 

 inches, is packed in ; and over this is placed a layer of 

 about four inches of fine, loamy soil to keep the potatoes 

 from coming in immechate contact with the manure, which 

 would rot or dry them. It is best to let the excess of heat 

 pass off, by waiting a few days before placing the potatoes 

 in the bed. Then, or as soon as the bed is ready, they 

 are pressed into the soft layer of earth, being placed as 

 near together as possible without touching. They are 

 then covered ^^ith a laj'er of loamy soil, which should 

 cover the most exposed roots to a depth of at least two 

 inches. For an early crop a movable covering of pine 

 leaves, or of cloth, or even a glass sash is sometimes em- 

 ployed. If leaves are used, they must be removed as soon 

 as sprouts appear, to avoid long, tender slips. If glass is 

 used, care must be given to ventilation. A trench around 

 the outside provides for drainage. 



"When necessary, this bed is watered. Excess of water 

 should be avoided, especially before the sprouts appear 

 above the surface, for watering is usually a coohng process, 

 and it may be a means of baking the surface soil. Keep 

 the surface layer pulverized, so as to decrease evaporation 

 and permit the easy emergence of the young shoots. Of 

 course all grass and weeds must be destroyed wliile young. 



412. Fire hot-beds. — These consist of a board floor 

 ■csdth an inclosed air space about two feet in depth under 

 the entire area of the floor. The sides of this space are 

 tightly closed by planks and by earth heaped against 

 them : or bv the earth walls left in excavating for the bed 



