186 GARDENING FOR PLEASURE. 



the early part of May, we have from four to six degrees 

 of frost, which would be fatal to all tender plains, which, 

 if covered by the protecting cloth, could be saved. I 

 have frequently been asked since the introduction of the 

 protecting cloth, whether it can be used instead of glass 

 for small greenhouses in winter. In very mild climates, 

 where there is but a few degrees of frost, it would answer 

 fairly well. The only objection would be in case of con- 

 tinued wet weather, as, of course, the cloth would not- 

 shed the rain unless placed at a very sharp angle. 



CHAPTER XXX. 

 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, twenty by 

 forty feet, and seven feet deep, had been made, 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 alternative 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 

 greenhouse over it, as the owner had a taste for cultivat- 

 ing plants. This suggestion was followed, and the walls 

 were raised two feet above the surface, and a span-roofed 

 greenhouse erected over it. 



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

 that the large volume of air in the excavation would at 



