180 Gardening 
a blanket over the backs so that it reaches to the floor 
all around. A well-lighted basement in which the fur- 
nace is located is often warm enough for growing. seed- 
lings. 
Since water gives off its heat slowly, watering with 
lukewarm water at bedtime helps to keep the soil warm 
‘at night, provided evaporation is checked. But be- 
cause of the cooling effect of the evaporation of water, 
it is well, unless the plants are covered at night, to 
water in the forenoon so that the top layers of soil are 
rather dry at night. 
The hotbed. A hotbed is simple in its construction 
and is not necessarily expensive. It consists of a glass- 
covered frame, which is placed over a bed of decaying 
manure. ‘The frame and glass keep out the cold air and 
keep in the warmth; the decaying manure supplies heat ; 
the glass allows the sunlight to enter during the day. 
The frame may be made of boards 13 or 2 inches thick 
Glass Plan of 
Z : corner / 
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Fic. 104. Diagram showing the details in the construction of a hotbed. 
