COMBINED CELLAR AND GREENHOUSE. 99 



surface, in order to give the necessary slope to receive the 

 sun's rays and to shed the water. A section of such a 

 pit is shown in fig. 46. If a pit of this kind is made in 

 a dry and sheltered position, and the glass covered by 

 light shutters of half -inch boards, it may be used to keep 

 all the hardier class of greenhouse plants, even in locali- 

 ties where the thermometer falls to zerc 



CHAPTER XXXI. 



COMBINED CELLAR AND GREENHOUSE. 



In connection with the description of the cold pit or 

 greenhouse without fire heat, may be mentioned the com- 

 bined cellar and greenhouse. Many years ago an acci- 

 dental circumstance gave me an opportunity of testing 

 the utility of such a structure. An excavation of 20 feet 

 by 40 had been made 7 feet deep, and walled up with 

 stone and beams laid across preparatory to placing a 

 building upon it, when the owner changed his plans and 

 found himself with this useless excavation within a dozen 

 yards of his costly residence. There seemed to be no al- 

 ternative but to fill it up or plank it over, but both plans 

 were objectionable, and in discussing how to get out of 

 the difficulty, I suggested erecting a low-roofed green- 

 house over it, as the owner had a taste for cultivating 

 plants. This suggestion was followed, and the walls were 

 raised one foot above the surface and a span-roofed green- 

 house erected over it. 



My idea, (which was found to be nearly correct), was, 

 that the large volume of air in the excavation would at 

 no season go below 40°, and be sufficient to keep the up- 

 per or greenhouse portion of the structure above the 



