Their roots were confined to a border inside the house, 4 feet wide and 18 inches deep. This border was heated by two rows of 4-inch pipes under pavement. There were no means of turning off this bottom-heat. Under one end of the pit there was a tank for collecting rain-water 9 feet long, where there was no bottom-heat. There were two vines planted in this division-one a white Frontignan, the other a Royal Muscadine. During the summer these two vines did not make the progress the others of the same kinds did where they had bottom-heat. And the following year the difference was far more remarkable. In consequence of the house being used for forcing strawberries and French beans, the vines were started at a higher temperature than they ought otherwise to have been.

The bottom-heat soon rose to 95°, and for a few days it was 100°. Those that had bottom-heat broke quicker by fourteen days, showing far more fruit than those that had it not, and were set and ready for thinning while those in the cold border were not in bloom; nor was their foliage much more than half the size of the same sorts of vines where they had the bottom-heat. I give this as an example of the good effect, as far as it goes, of bottom-heat for vines when applied to an extent that many utterly condemn. And I confess that if I had had a stop-valve on the bottom-heat pipes, I would have moderated the heat as compared with what it was.

The mere heating of the soil of the border by these appliances is not the only advantage that results. There is the additional and important one of the constant passage of air through the soil, forced up through it when heat expands that in the air-drains and interstices amongst the brickbats, and down through it when the air in the drains cools and contracts.

When the difficulty of getting a boiler fixed at a sufficiently low level to heat the pipes for warming the border cannot be overcome, as must often be the case where the country is level and the drainage bad, the best substitute is, to make all the arrangements as to air-drains I have described as necessary when pipes are laid, and to connect these subsoil air-chambers with the atmosphere of the interior of the vinery by a series of drain-pipes along the front of the house near the hotwater pipes. Along the back wall of the vinery construct an underground air-drain, to be connected by a series of pipes, 4 inches in diameter, with the general underground air-chambers of the border. From this drain another series of pipes should be carried up the back wall some 7 or 8 feet, when they should have openings into the interior of the vinery; and if the flue from the boiler is made to run along the back wall in such a way as to heat the air in the upright air-drains, it will become lighter and escape into the general atmosphere of the house; while at the same time a current of air will pass down the front air-pipes already referred to, at a lower temperature than that escaping from the outlets in the back wall, but sufficiently warm to be of great benefit to the roots of the vines. This arrangement has the additional advantage of keeping the air in the house in constant motion. There is also the possibility of making such arrangements in forming a vine-border as to admit of the application of dung-linings for warming the soil. It is, however, only necessary to have heat applied to the roots, as here described, in cases where grapes have to be forced early. If the vines are not started till the beginning of March they will do perfectly well without it, as is evident from everyday experience.

VENTILATION.

This is a point of great importance, and, in very early forcing, one of considerable difficulty; for it not unfrequently happens that, after a severe frost at night, requiring hot pipes, the sun breaks forth in the morning and raises the temperature of the vinery beyond a safe point, while at the same time the wind may be piercingly cold. In such circumstances there is no alternative but to open the top ventilators, when the hot air will rush out; but at the same time another current will rush into the house, of air too cold to be admitted amongst the tender foliage of the vine with safety. To modify this evil, it is a good plan to have a light wooden frame made to fit the ventilating opening, and over this frame to tack a sheet of perforated zinc, or a double piece of Hawthorn's hexagonal netting. This will break up the rush of air into a great many small streams that will more readily mingle with the hot air of the house, and get so far heated before it reaches the foliage. It would be no safer to admit the cold air by the front ventilating-sashes to take the place of that making its exit by the top ones, unless some means were employed

to take the chill off it before it is discharged into the body of the house. For this purpose I have designed what I have termed "The Hot-Air Ventilator" (fig. 5).

This apparatus consists of a sheath of copper placed over a row of the front pipes. The diameter of this sheath is one inch more than the hot pipe it encloses, consequently there is an open space of half an inch all round the pipe inside the sheath. This cavity is fed with fresh air from the exterior of the house by a pipe 5 inches in diameter, which springs from the lower surface of the sheath, and passes through the front wall of the house to the external air. There is a valve in this feedpipe to modify the supply of fresh air at pleasure. In the upper surface of the sheath is a double row of small holes, so that the moment the cold air comes into the chamber round the pipe, and gets hot, expanded, and lighter, it makes it exit through these holes into the general atmosphere of the house. In our early vineries the valves are kept open constantly, both night and day, with great advantage to both fruit and foliage.

CONSTRUCTION OF VINERY.

As a rule, whether for early or late forcing, I prefer a good-sized house,-say, height of back wall, 15 feet; width of house, 15 feet; height of front sashes, 2 feet; length, 40 feet. A house of these dimensions has a good length of rafter, which enables the vines to carry a large extent of foliage, and become vigorous plants as compared with those confined to a short rafter; and the roof presents an angle of about 35° to the sun-a very suitable one for a vinery; while the length of the rafter will be about 19 feet. If the roof is constructed of sashes and rafters, the sashes should be 6 feet wide, so as to afford space enough for training one vine-rod up under each rafter, and one in the centre of each sash :

if all of astragals, as is sometimes the case, the rods may be regulated as to distance from each other at pleasure. The wires to which the vines are tied should not be nearer the glass than 16 inches, and should run at right angles with the rafters. When they are too close to the glass, as is often the case, the leaves come in contact with it, when they get killed by being, as some say, scorched, but in reality frozen. These wires should be within 10 or 12 inches of each other. There is no pathway so suitable, either for a vinery or peach-house, as iron-grating. In a house of the dimensions I have here indicated, and where grapes are to be ripe in April, there should not be less than 300 feet of 4-inch pipe for surface or atmospheric heat, in addition to which there should be a steaming-tray, which gives off fully as much heat itself as one row of pipe. The front and ends of the house should rest either on pillars or arches, so as to give the roots free access to the outside as well as inside border. The front row of pipes should be 18 inches from the front wall, and the permanent vines planted equidistant from front wall and pipes. The supernumerary vines should be planted 12 inches inside the pipes.

SUBSOIL AND DRAINAGE.

Where the entire border is heated by hot-water pipes covered with Caithness pavement, as shown in fig. 1, any excess of water that may fall on the border will descend through the joints of the pavement to the chamber the pipes occupy, from which a drain should be laid down. to remove it at once. But where bottom-heat is not so applied, and where the subsoil is of a cold, wet, ferru