256 
ON THE CONSTRUCTION AND HEATING OF HOT-HOUSES. 
in stone ; each sash swings open with a pivot : the spout, Z>, is four inches wide, 
and rests upon the uprights of the front sashes, 
fastening- to them with screws. The astragals or 
sash bars, a, should be the size and weight of one 
pound to a foot, and screwed at one end to the spout, 
and the other to the stone coping at the top, d. 
The rafters are four inches wide, and half an inch 
thick : the lights in front all swing open : there is 
also a light over each door, to slide or swing, and 
three slides of wood in the back wall, within six 
inches of the top, to let off the vapours when neces- 
sary. The roof is all fast, and the air is admitted 
through the back, front, and ends of the house. 
PROBABLE EXPENSES OF ERECTION, &c. 
£ 
s. 
d. 
Price of Glass, 1,100 feet of thirds, 6 by 4, at 1\d. per foot 
34 
7 
6 
Putty, 5 cwt., at 18s. per cwt. . . . . 
. 4 
10 
0 
Labour . . . . . 
4 
0 
0 
Astragals or Sash-bars, \h\ cwt., at 12s. 
. 9 
6 
0 
Nine Uprights in front, 2 cwt., at 10s. per cwt. 
1 
0 
0 
Two End-rafters, 3 cwt., at 10s. 
. 1 
10 
0 
Thirty feet of Spouting, 3 cwt., at 10s. 
1 
10 
0 
Thirty feet of cross-pieces to support the Astragals, 2 cwt., at 10s. 
per cwt. 1 
0 
0 
Three Uprights for ditto, 2^ cwt., at 10s. 
1 
2 
G 
Eight front Sashes, <L\ cwt., at 12s. . . . . 
. 1 
10 
0 
Ninety feet of Stone Coping, at 6d. per foot 
2 
5 
0 
13,656 Bricks, Labour, Lime, &c. . . . . 
. 42 
15 
0 
Wood Work for Doors and Frames 
3 
0 
0 
Three Slides to admit air through the back- wall 
. 0 
12 
0 
Screws, Labour, fixing Astragals, &c. 
4 
0 
0 
Three stones of Stone-coloured Paint . . . . 
. 5 
10 
0 
Whole cost of the erection, independent of the heating apparatus 
. £117 
13 
0 
Fourthly, The season when the most light will be required, which determines 
the angle or slope of the roof. 
In all houses for plants, as much light and sunshine is required as possible 
during the winter months ; when, therefore, they are built in the ordinary form, it 
is always advisable to have front upright sashes, to catch the rays of the sun from 
November to February, and a sloping roof for spring, summer, and autumn. If 
there are no front sashes, the angle of the roof should be constructed somewhat dif- 
ferently. 
On looking over a popular French work on gardening, it would appear that the 
