DESCEIFTIOX OF HOUSE. 



59 



falls below the freezing point, and our experience in their culture enables us 

 to say that they are capable of enduring a considerable degree of cold with 

 impunity. Like aU mountain plants, they wiU not long flourish in a damp, 

 csr impure atmosphere, nor in one, however dry, if excluded from a free 

 circulation of air, and fuU exposure to solar Hght. It follows, therefore, 

 t3iat in the selection of a proper habitation for them, one fuUy exposed 

 to the sun, and in a perfectly dry situation, and constructed so that the 

 plants may stand near the glass, capable at the same time of ventilation 

 to the fullest extent, with the front and roof sashes rendered moveable 

 when required, wHl be the most proper habitation for them. 



The annexed section wiU give some idea of what may be considered 

 an economical and useful heath house, and may be of any length required, 

 from twenty to one hundred feet ; the height over the passage should not 

 exceed seven feet, which wiU be ample space to walk under ; the width 

 twelve feet, allowing three and a half feet for the passage, four and a half 

 for the left hand stand for the largest specimens to be placed on, and 

 four feet for the front platform, on which the smaller plants are to he 

 placed. These platforms might be formed of ^Welsh slate, perforated to 

 admit of the superflous water passing off, and also to aUow a circu- 

 lation of air to pass through amongst the plants. The front sashes 

 should be eighteen inches high, and the front platform about level with 

 the wall plate. The cavities under the plant tables should be left open, so 

 that no tendency to generate damp may be encomaged ; and under the 

 front platfoiTu the flue (a) should be placed, its principal use being to dry 

 up superabundant humidity, and to repel the frost when it is \eTy severe ; 



