STRUCTURE OF ORCHID HOUSE 11 
timber should be avoided. In glazing, only a thin bedding 
of putty should be used, and the glass should be bradded on 
the upper side, as top putty when decaying or on becoming 
loose is worse than useless, and tends seriously to foul the 
water in the cisterns. Span-roofed houses 12 feet to 15 feet 
wide, and of proportionate elevation, are suitable for ordi- 
nary Orchids, but if specimen plants are desired a loftier 
house will be necessary. 
A range of houses should, if possible, be connected at 
the end which is most exposed to the north and north-east 
winds by a corridor or covered structure, in which the pot- 
ting-shed stores and entrance to the boiler hold should be 
arranged. The greatest care must be taken that no fumes 
from the heating apparatus can find their way into either 
the corridor, potting-sheds, or plant-houses, or the plants 
will suffer the worst consequences. Safety can easily be 
assured by thoroughly ventilating the stoke-hold and making 
the partition between the corridor or offices and the stoke- 
hold as air-tight as possible. 
The wood-work, when of pitch-pine or other hard wood 
planed smooth, may be oiled or varnished, painting being 
undesirable for new houses. In course of time, however, 
painting has to be resorted to, and it is one of the most 
trying operations about the Orchid houses. Great care has 
to be taken to obtain a reliable quality of paint that will 
not harm the plants, and to keep the house vacant for as 
long a time as possible for the gases from the paint to 
escape. After the plants are returned to the house some 
ventilation must be maintained day and night for a time. 
Tar should not be used inside an Orchid house for any 
purpose, 
