STRUCTURE OF ORCHID HOUSE 4g 
CHAPTER IV 
STRUCTURE OF THE ORCHID HOUSE 
So far as the improvements in present-day Orchid houses 
are concerned, these are not due to the imagination of the 
horticultural builder, but to the experience of the Orchid 
grower. It is owing to him that the old-time glass sides, 
with their hinged ventilators on a level with the plants, and 
many other harmful arrangements, have been abandoned. 
Moderately low, span-roofed houses, extending north and 
south for preference—although the aspect does not seem 
to be of vital importance—are the best, the sides being 
wholly of brick, and also the ends of all but the large 
houses, in which the upper part may be formed of wood 
and glass. 
The top ventilation should be admitted through venti- 
lators placed at the highest point of the ridge, and they 
are usually worked by a continuous system manipulated at 
one end. The lower ventilators should be small ones fixed 
in the brick-work at the sides of the house, and they may 
be arranged to be regulated from the outside, or by means 
of rods attached to the flaps on the inside and reaching to 
the path, being carried beneath the staging. The natural 
earth is the best base for an Orchid house, and open wood- 
work trellises placed on the natural earth are far preferable 
to tiled paths, therefore their use is strongly recommended. 
Beneath the central stage, from end to end, deep tanks with 
cemented interior should be provided, because rain-water 
