Jan.] THE HOT-HOUSE. 97 
wall-plate, running under a proper coping of wood or lead, fixed 
along above close to the wall, and lapped down with due width to* 
cover and shoot off the wet sufficiently from the upper termination 
of these sashes: likewise along the outer edge of the top or crown- 
plate in front, may be a small conductor of lead or wood, to receive 
the water from the slope-glasses and convey it to one or both ends, 
without running down upon the upright sashes; being careful that 
the top part behind is well framed and secured, water-tight, and 
finish the top of the back wall a little higher than the glasses, with 
a neat coping the whole length. 
In every part, the wood-work must be made with the most criti- 
cal exactness, and all the sashes so fitted as to slide close and free; 
neat stays of iron may be placed on the under side of the roof lights, 
sunk into the wood and made fast by wood screws, in order to 
strengthen them; and the rafters or cross-bars are to be stayed 
with wood, at proper distances, to keep each firm in its place. In 
wide stoves it will also be necessary to place a neat upright, either 
of wood or iron, inside, under each of these rafters, to prevent their 
bending under the weight of the glasses, which are generally made 
to rest on the back-wall of the bark pit. 
In glazing the roof-lights the panes are to lap over each other 
about half an inch; the vacancies where they overlap are by some 
closed up with putty, others leave them open, which is the better 
way when not too wide; in order both for the air to enter moderately, 
and for the rancid vapours, arising from the fermentation of the bark- 
bed, Sec. within, thereby to be suffered to pass off; and also that such 
as condense against the glasses, may discharge itself at those places 
without dropping upon the plants: the glass for this purpose should 
be of a small size, and not more than from six to eight inches 
square; such would lap closer than larger sized glass; and form a 
much stronger roof. The great apertures occasioned by the crook- 
edness of large panes admit the cold air so copiously in severe 
weather, that incessant fires must be kept up to counteract it, which 
certainly is injurous to the plants; but of two evils you must take 
the least; and, besides, an extraordinary quantity of fuel is consum- 
ed this way which might be saved, and the plants kept in better 
health, by adopting the smaller sized glass. Generally when a 
large pane is pinned down, so as to form some kind of a close lap, 
it presses so hard on the other, that one of them, and sometimes 
both crack; which permits the rain to run down frequently on 
plants that too much moisture in the winter season will absolutely 
destroy. As to the upright glasses, in the front and ends, they are 
to be glazed in the ordinary way of house sashes. 
The inside walls should all be well plastered; the flues must 
also be finished off with the best plastering-mortar that can be 
made, in order to prevent any cracks through which the smoke 
might pass into the house, which cannot be too carefully guarded 
against, as it is extremely injurious to plants, causing them to drop 
their leaves, and if continued long in the house will totally destroy 
them. 
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