THE PINE APPLE. 35 



a useless opaque roof over the path, an excellent 

 place is formed for training a vine ; and this being 

 at all times the hottest part of the house, such vines 

 as are there trained will produce very early and 

 high-flavoured fruit. 



The succession-house of Miller has no upright 

 glass, and only a walk at the back of the house : 

 the bark-pit may be partly sunk in the ground, if 

 the situation be dry ; or if wet, kept above it. 

 The flue makes three returns against the back wall, 

 beginning from the level of the walk. Many per- 

 sons, he says, have made tan-beds, with two flues 

 running through the back wall, and covered with 

 glasses, like common hot-beds ; but, besides the in- 

 convenience of taking off the glasses when the 

 plants want water, the damps rise in winter when 

 the glasses are closely shut, and there is danger of 

 the tan taking fire. 



The improvement on this plan consists in de- 

 taching the flue from the back wall, and separating 

 it from the tan by a vacuity of two or three inches ; 

 or, what is still better, placing the flue in front 

 similarly detached, and surrounded by air on all 

 sides. 



D 2 



