The tan-pit need not be deeper than three feet, or three feet six inches; and the path which surrounds it should not be narrower than twenty inches; but two feet, or for the back pit two feet and a half, will be better. The vines are introduced under the sill of the front glasses, and trained up the rafters; and Mr. M’Phail’s practice is not to withdraw them in the winter season as is done by other gardeners. The surface of the tan-bed should not be nearer the glass than five or six feet. Two houses, each forty feet in length, joined together, can be kept warm with two fires, better than one house of forty feet; but in cold, exposed situations, he would recommend diminishing the length. With respect to pits, M’Phail observes, “Succession Pine plants grow exceedingly well in pits covered with glazed frames, linings of warm dung being applied to them in cold frosty weather. The north wall of a pit for this purpose had best be only about four feet above the ground; and if about two feet high of it the whole length of the wall beginning just at the surface of the ground four feet below the height of the wall, be built in the form of the outside walls of my cucumber bed, the lining will warm the air in the pit more easily than if the wall were built solid. The linings of dung should not be lower in their foundation than the surface of the tan in the pits in which the plants grow (for it is not the tan that requires to be warmed, but the air among the plants); and as during the winter the heat of the air in the pit among the plants, exclusive of sun heat, is not required to be greater than from sixty to sixty-five degrees, strong linings are not wanted: one against the north side, kept up in cold weather nearly as high as the wall, will be sufficient, unless the weather get very cold indeed, in which case a lining on the south side may be applied. In cold frosty weather a covering of hay or of straw, or of fern, can be laid on the glass above mats in the night-time. [Illustration: 10] “The brick bed of my inventing, (fig. 10.) for forcing early cucumbers, answers well for growing small succession plants. A pit built on the same construction, but of larger dimensions, without cross flues, is a suitable one for growing Pine Apple plants of any size; for by linings of dung the air in it can be kept to a degree of heat sufficient to grow and ripen the Pine Apple in summer, as well as it can be done with fire heat, only it will require a little more labour and plenty of dung.