The other three divisions of the range, E, F, G, are grape houses. The back walls are all covered with trellises. A vine is planted in the middle, and trained on the trellis at the top of the house, where in general there is plenty of light in the early time of forcing. The lower part of the trellis is covered with fig-trees, which, as already men tioned, § 213. have been found to succeed very well in such situations. Fig. 3. Plate CCCX. is a section of division F.
In all the houses of this suite, air is given by moving the upper sashes by means of weights and pulleys placed in a cavity in the back wall, as seen at a a a, in the sections, Figs. 3, 4, and 5.
Into each of the hot-houses is introduced a three-quarter inch pipe, coming from an inch one, which passes along the back of the walls' The cocks are of the same kind as those in the walls already described ; and the directors, when screwed upon them, water the houses with very little trouble, and are exceedingly useful in keeping tinder the red spider, and other insects.
237. On the north side of this range, opposite to the mid dle hothouse, is a mushroom-house, constructed on Old acre's plan, (to be afterwards described). It has a large and a small pit, with four shelves on the back wall, and three shelves on each of the two ends, all of which may be used for the purpose of raising mushrooms, either at the same time, or in succession. The large pit is partly filled with earth, and kitchen vegetables are kept in it in time of severe frost. Sea cale can also occasionally be forced in this pit. Fig. 4. Plate CCCX. is the section of the mush room-house, and also of the middle peach-house, the ground plan of the mushroom-house being at H, and of the peach-house at A.
238. On the east side of the garden is situated the me lon ground. The garden wall is extended on the north of it to the length of 152 feet, of the samehcight as the other walls, and fitted like the rest of the wall having a south aspect. The pine-stoves are situated here. The ground on which they stand falls considerably from north to south. The furnaces are placed on the south side of the stoves; and, on the same side, there is a narrow nursing pit, four feet broad, the whole length of the house. This pit may, at pleasure, be divided, at the furnaces, into three divisions, n, D, D. The glass-roof of the pit covers the top of the furnaces, and from thence heated air is intro duced, by means of apertures with dampers, into either pit as it wanted. Heated air can also be admitted from the stove to the small pit, by means of openings in cast iron doors, which can be shut when required. When still more of the warm air is wished to be communicated from the stove to the small pit, the doors are made to lift out alto gether, and as the front flue of the stove passes these doors, the heated air has free access to rush in ; or it can be admitted from the vacuities between the flue and front wall. As the tan in the small pit is of no great body, and cannot long maintain its heat, the front of the pit is built of brick, with pillars and holes similar to a pigeon house; and there is an inclosed space in front of it, to receive a lining of warm dung, when the heat is wished to be in creased. This lining is covered over with flooring, which forms part of the walk, tends to prevent the dissipation of the heat, and gives the whole a neat and clean appearance.
The spaces over the top of the furnaces can at pleasure be converted into distinct or separate forcing places, by putting in the covers of the dampers, and fixing two wood en divisions across, at the extremities of the furnaces. In these places, potatoes may be forced in early spring ; or, if a taste for fine flowers be indulged, the single and the double Cape jasmine, (Gardenia florida, L.) which are not easily brought to blossom, may here be made to flower, by placing the pots among wet mosses, (hypnums,) the moist heat thus supplied proving very congenial to the plant. From the spaces over the top of the furnaces the heated air can at pleasure be directed into either of the two suc cession houses, being admitted by removing one or other of the covered dampers at d, d, Fig. 1. Plate CCCXI.
There are niches along the back wall of the pine-stove, nearly opposite to the middle of each sash. They are nar row on the outside, but are bevelled inwards to at least double their exterior width. The bevelled sides are plas tered, and covered with a trellis ; on these, grape vines are trained, the principal shoot, after reaching the roof, being conducted down the rafter, as far as the first row of pine plants in the back of the pit. To these recesses two sets of shutters are adapted, one for the outside, the other for the inside. During winter the outer shutter is removed, and the inside shutter employed. The vine, after being pruned, is led without, and fixed there during winter, ex posed to the cold of that severe season. When brought in to be forced, the inner shutter is of course removed, and the outer shutter put in. The time of forcing these vines may thus, in a great measure, be regulated by the garden er, and made to suit the conveniency of the family. Fig. 1. Plate CCCXI. is the ground-plan of this pine-stove. A is the first succession-pit, containing nine sashes ; B the se cond succession-pit, with ten sashes; and C the fruiting-pit, with eleven sashes. Fig. 2. is the elevation. Fig. 3. is the section ; and it will be observed, that, for the sake of dis tinctness, this section is drawn to an enlarged scale, nearly double that employed in drawing the ground plan and ele vation of the stove, Plate CCCXI. At k is a moveable gangway, eighteen inches broad over the glass roof of the narrow pit, for giving access to the front of the stove. It may be mentioned, that there are two returns of the flue beneath the pathway at the back of the pit. The heated air is drawn from between these two flues by means of cast metal covered dampers, b, b, Er.c. in Fig. 1,; the covers being only put on while the workmen are changing the tan in the pit, or on similar occasions. The small holes seen in the back wall of the ground plan, Fig. 1. a a, &c. commu nicate with the cavities of the flue on the side next to the back wall. Those seen in the curb or back wall of the tan pit c c, Ste. communicate with the cavity of the flue next to it ;. and those in the path-way b b with the cavity between the flues. In this way, heated air is drawn from the sides of the flues at thirteen places on the back wall of the house, and at ten places on the curb of the pit.