350 



FRUIT-HOUSES. 



a circulation throughout the whole house, 

 and, at the same time, equalising the tem- 

 perature ; which, without this agitation, 

 would remain in a sluggish state about 



Fig. 



the lower and front part only, and conse- 

 quently heat those parts more than the 

 others. The pipes being placed so low, 

 heat the borders slightly by conduction ; 

 472. 



and this might be carried to a consider- 

 able extent by leading flues or air-drains 

 through them. The pipes are also out 

 of the way, and a useful bottom heat is 

 always at command, as plants in pots or 

 boxes may be set over them. The lower 

 part of these chambers being water-tight, 

 could be supplied by a small pipe from 

 the cistern, so as to cover a portion of 

 the lower pipe. A genial steam would 

 at all required times be thus obtained, and 

 vapour would thus be given out more 

 equally, and much less heated, than by 

 evaporating troughs on the upper pipes, or 

 by throwing water on them. The impure 

 air escapes by the ventilators in the top 

 of the back wall. The trees are planted 

 along the back wall, which is completely 

 covered to within 2\ feet of the floor ; 

 others are planted in the narrow border 

 between the air-chamber and the front 

 parapet wall, which is supported on piers, 

 and lintelled over with stone; and under 

 which stone, and between the piers, the 

 roots extend themselves to the external 

 border. The trees planted in front are 

 trained to a curved trellis rising from 



the ground and falling backwards; and 

 branches both of them, and also of those 

 in the back, are trained to the gable trel- 

 lises suspended under each alternate 

 rafter — thus giving the greatest possible 

 extent of surface, and the least possible 

 extent of shade. 



In other houses, the gable trellises are 

 omitted, as in fig. 473; but the front 



Fig. 473, 



