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k. Two rooms, in which are the furnaces, but which may be also used for potting or shifting plants, &c. or fitted up as seed- or fruit-rooms.

r. Glass division, in order to admit of different management or original disposition in respect to the fruits to be forced, 8. Rolls of canvass, which form the outer roofing, and are let down and drawn up in the manner of common linen window blinds. The ends are covered by gores of canvass, rolled up under the coping of the front wall, and drawn to the apex, on the same principle as the others are let down. The same slope of glass adopted in this design is of course applicable to any dimension or description of house; to various modes of opening the glasses for air, and arranging the trellis, flues, back wall, &c. To illustrate this I shall give the outline of five different modes, answering to the five remaining sections in PLATE V.

In Fig. 4. iron rafters are fixed six or eight feet asunder, and iron frames of such a length as to reach from centre to centre of the rafters, and three or three feet and half broad, are placed on them, and attached to the rafters by hinges at the upper angles. The astragals are placed in the direction of the breadth, not of the length, of these frames; and the styles either formed to the curve of the roof, or the curve reduced to part of a polygon, whose sides are each three feet and half. This arrangement properly completed, then by means of levers attached to each frame, either inside or outside the house, the whole roof may be raised, either to the perpendicular to admit a shower, or to any required angle, according to the sun's altitude at the hour of the day and season of the year. The detail of the construction requisite for this operation is given in PLATE VII. which will be afterwards referred to.

a. (in Fig. 4.) represents the levers.

b. The cord attached to them.

c. The situation of the sashes, raised at an angle to admit the sun at midsummer to every part of the house.

d. The situation of the sashes, raised perpendicularly or to the greatest required elevation, so as to admit a shower of rain. e. Front trellis, with intervals of two feet opposite the centre of each sash.

f. Secondary trellis', two feet behind the other, for temporary purposes, or laying back barren wood from the principal

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In Fig. 5. there is no perpendicular back wall, but the glass and trellis are placed on the south side of a longitudinal arch or vault of brickwork. The glass is divided into two parts; the first, composing two-thirds of the whole slope, consists of astragals without rafters, their lower ends placed ridge and furrow ways on the coping of the front wall, but their upper ends terminating in one plane on a horizontal bearing bar, represented by a. The remaining third of the glass is intended to open, and consists of frames glazed in the common mode, hinged at the upper edge, and resting by the lower on the above horizontal bar. These frames are raised by means of a lever, &c. as in the last example.

1

a. The horizontal bearing bar with supports.

b b. Valves for ventilation, and which, from their situation and the effect of the sun in heating the narrow volume of air between the glass and the brickwork, will be sufficient to lower the house to the temperature of the open air in the hottest day of summer.

C.

d,

Valve for admitting heated air from

which may either be a receptacle for the smoke after it has made the transit of the front flue, or it may be used as a

See Nicol; also Henderson in Niel, "on Scottish Gardens aud Orchards,” in the General Report on Scotland, &c. chap. ix.

place of fermentation for short grass, weeds, dung, tan, &c. the heated air from which may, at certain seasons, be let into the house; or it may be used for both purposes; or for steam; or merely as a reservoir of temperate air, to be interchanged as occasion may require.

e. Front trellis.

f. Back ditto.

g. Outer curtain or roofing.

Fig. 6. Here the glass roof, trellises, and mode of ventilation, are in all respects the same as in the last figure; but instead of a whole, there is only a half vault, resting on cross parapets, and abutting against the upper part of the back wall. It is therefore a variation of Fig. 5. adapted to gardens where the walls are already built. The ground plan of the cross walls, and the manner in which this half vault is to be built, will be understood from inspecting Fig. 4, PL. VI. in which

a. represents the piers of the arches of the cross bearing walls. b. The foundation of the connected segments of the semivault. c. The back wall.

In Fig. 7, PL. V., is shown the mode of adapting the fruiting-pit of a pinery to this description of roof. The inclination of the bark-bed is parallel to that of the roof; but as tan, leaves, or dung, will not subside in such a position with sufficient regularity to keep the pots upright, deal boards may be placed on edge in the bark, lengthways of the house, and with their upper edges arranged to the required section, and so as to retain level each row of pots. Another mode is to place a cast iron frame or netting on the surface of the bark-bed, having holes or rings for holding the pots, and so contrived as to sink as the bed sinks. By either of these modes the plants will be kept upright, and at an equal distance from the glass.

The reader need not be told the reason why those plants which are intended to fruit in November, December, January, and February, are to be placed in the first and second rows; those in March and April, in the third; May and June, in the fourth; and so on.

Where neither leaves nor bark are used, but the plants merely plunged in rotted dung or earth', or where bottom heat is supplied by steam2, no boards or frame will be requisite; and in these cases the superiority of this style of roof will be obvious.

a... b. Section of the cast iron frame for retaining the pots.

C.

d.

e.

f.

g.

h.

i.

Walks and flues under.

Bárk-pit.

Vault under.

Steaming-pipe for bottom heat.

Branches from the steaming-pipe for steaming the air of the house.

Back shed and reservoir of air for the purposes of ventilation.

Openings for the same purpose.

Fig. 5, PL. VI. is a plan of the cast iron framing, which may be cast in pieces to be joined by hose at a, a, a, &c.

This construction is calculated to remove a very great objection to the best modern pineries, which is, the obliquity of both the glass and the pit to the sun's rays in the winter season. In some of the best pineries the sloping glass is placed at an angle of 20 degrees, and the pit in which the plants are plunged is level. By this means not only a large proportion of the incidental rays are reflected off the glass, but those which enter are oblique to the plants. If there is front glass, the sun will enter it with more effect; but the plants being on a level, the degree of obliquity at which his rays fall on them is as great or greater than before3.

1 Pines planted on a bank of earth in a glass case constructed from my plans, were grown with great success at Underley Park, near Kendall, Westmoreland, the seat of Alexander Nowell, esq. from 1809 to 1811.-I have not since heard from that quarter, but have no reason to believe they are not still in a thriving state.

For instances of this see "A short Treatise on Hothouses," Edin. 1805, by the author of these Remarks.

In a pinery which I have lately erected in South Wales, I have, besides adapting the slope

Fig. 8. Here the same description of glass roof is shown, as placed against the south side of a gardener's house or row of cottages, and the air to be heated by their fires. This is readily accomplished, either by raising the flues two feet higher than usual, or by lowering the floor of the cottages relatively to that of the house.

The roof of the cottage may either be constructed of timber and tiled in the usual manner, or for durability it may be of arched masonry. In this last case, as a nine-inch brick wall would be too slight, and as a fourteen-inch wall would require such a quantity of bricks as to occasion considerable expense, these three methods may be substituted for a common roof:

1. Cross walls, as in Fig. 4, PL. VI., but at such a distance as to form one apartment between each, may be adopted, with the lateral arched walls of nine instead of four inches.

2. Cast iron rafters, with flanches, may be substituted for these cross walls, and double the number used; in which case a four-inch lateral arch will be sufficiently strong. Fig. 7, PL. VI. shows a plan of part of these lateral arches, abutting on the ribs.

a. The ribs of cast iron.

b. Wrought iron rods, which tie them together.

c. Segments which form the lateral arches.

3. One large arch may be used, forming the brickwork, so as the section of a fourteen-inch wall may be in fact a zig-zag four-inch wall, as in Fig. 6, PL. VI. I have proved this to be equally strong as a fourteen-inch wall, while it does not consume many more than one third of the bricks. It would also, in all the seven designs which have been described, correspond admirably with the intention of the ridge and furrow glazing; since, when the sun's rays were perpendi

of the pit to that of the sloping glass, contrived a stage immediately adjoining the front glass, on which to place pines coming into fruit during the winter months, for their greater enjoyment of the sun's rays, without which there can be no flavour in fruits.

'In a garden wall erected here (Bayswater), 125 feet long and 8 feet high, the upper part of which is merely brick on edge, and all the rest four-inch work, or brick on bed.

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