188 GARDENING FOR PLEASURE. 



feet deep, walled up to about one foot above the surface. 

 When complete it would show something like the section 

 in figure 65. If desired, the walls might be raised two 

 feet above the surface level, which would admit of a few 

 windows in the wall to give light in the cellar, if so de- 

 sired. If the glass roof is made fixed, it should have 

 ventilating sashes three by three, at intervals of six or 

 nine feet on each side of the roof ; if of sashes, they 

 should be seven feet long by three feet wide, every alter- 

 nate one being arranged to move for ventilation in the 

 usual way. The position of the structure would be best 

 with its ends north and south. The shutters for cover- 



Fig. 65. GREENHOUSE AND CELLAR COMBINED. 



ing the glass at night should be made of light half-inch 

 pine boards, three feet wide by seven feet long. 



It will be understood that the advantage of this com- 

 bination of cellar and greenhouse over the ordinary cold 

 pit is, that the air of the greenhouse is warmed or 

 equalized by mixing with the atmosphere of the cellar, 

 which will rarely be less than forty degrees. For the 

 same reason, if a high temperature by fire heat were 

 wanted, say seventy degrees, this large body of air from 

 below of forty degrees would make it difficult to obtain 



