chap, el] heat of hotbeds. 29 



level the surlace of the manure before covering 

 it with earth. The seeds to be raised may 

 either be sown in this earth, or in pots to be 

 plunged in it. 



Tlie proper average heat for a hotbed in- 

 tended to raise flower seeds or to grow cucum- 

 bers is 60°; but melons require a heat of 6-5° 

 to grow in, and 75° to ripen their fruit. This 

 heat should be taken in the morning, and does 

 not include that of the sun in the middle of the 

 dav. "When the heat of the bed becomes so 



J 



great as to be in danger of injuring the plants, 

 the obvious remedy is to give air by raising the 

 glasses; and if this be not sufficient, the general 

 heat of the bed must be lowered bv making 

 excavations in the dung from the sides, so as to 

 reach nearly to the middle of the bed, and 

 filling up these excavations with cold dung 

 which has already undergone fermentation, or 

 with leaves, turf, or any other similar material 

 which will receive heat, but not increase it. 

 "When the heat of the bed falls down to 48° or 

 lower, it should be raised, by applying on the 

 outside fresh coatings of dung, grass, or leaves, 

 which are called linings. 



"When hotbeds are made of spent tanner's 

 bark or decayed leaves, a kind of box or pit 

 must be formed of bricks or boards, or even of 

 layers of turf or clay, and the tan or leaves 

 filled in so as to make a bed. Where neatness 

 is an object, this kind of bed is preferable to 

 any other ; but a common hotbed of stable ma- 

 nure may be made to look neat by thatching the 

 outside with straw, or covering it with bast mats 

 pegged down to keep them close to the bed. 



