536 



On the Construction 



h7#. 



a, Outer sashes. J, Inner sashes. c, Space between the sashes, cut through the rafters, 



d, Space in the wall for warmed air, or hot- water pipes, &c. e, Wall plate. 



/, Front wall, hollow. g, Back wall, also hollow. h, Hole through the wall-plate. 



the sashes, through perforations in the wall-plate on which 

 they stand ; the rafters have also open spaces through their 

 sides, to facilitate the equable diffusion of the warmth, which 

 is thus spread as a covering over the whole house. The ad- 

 vantage which this method of keeping out the cold affords for 

 the cultivation of plants which only require protection in win- 

 ter, such as ericas, camellias, and New Holland plants, for 

 which the above-mentioned conservatory is designed, is very 

 great. 



For stoves, where a higher temperature is required, a flue 

 in the inside of the house would be necessary ; and this, if 

 placed in contact with the inner side of the double wall, would 

 be sufficient to heat both the air of the house and that con- 

 tained between the sashes. It is, however, of no consequence 

 whether the source of heat be hot-water pipes, steam, or 

 fire flues ; and, provided the principal object (the warming 

 between the sashes) is attended to, many advantageous varia- 

 tions may be adopted, according to the purpose for which the 

 house is intended ; as hot-water pipes between the hollow 

 walls, and flues in the interior of the house, both heated by 



