284 FLOWER GARDEN. 
roofs and a double stage; but they have a very plain 
appearance, especially those which are commonly erected 
in nursery gardens. They might be made much more orna- 
mental, with little loss of light, as in the accompanying 
figure (Fig. 18), which is designed for the south end of 
one of these span-roofed houses. The plants have thus an 
east and west aspect, or enjoy the morning and afternoon 
sun. Such houses may indeed assume any form which 
taste can suggest, provided there be a sufficiency of light, 
and the plants be not too far from the glass. The heath- 
house does not essentially differ from the green-house; but 
for it a span-roof is decidedly preferable, and provision 
should be made for the most thorough ventilation. 
In the Conservatory, the chief plants grow in beds of 
earth sunk in the floor. The following figure shows the 
principle of this species of house. The beds, marked & 3, 
are filled wits a light soil, calculated for the plants which 
are to inhabit them. This figure.represents the front ele- 
Fig. 20, 
Ais AI A Ai, 
