In the Hot-house at St. Helen's, Derby, the vines were formerly planted in the inside of the house, and rather too deep; but Mr. Mackay, the present gardener, planted them on the outside, in 1829, and they have since done well, and produced extraordinary crops. The glass roof, which is of the ridge and furrow kind, is entirely fixed, but it contains ventilators for admitting air, and the whole is now managed with the greatest ease. The heat is produced from a cockle stove, and a continual flow of warm air is poured into the house, in the same manner as is done in warming the Messrs. Strutt's manufactories. This warm air, in the most severe weather, is, by a very simple contrivance, more easily conceived than described, returned to the cockle, and heated and reissued to the house, so that, at that season, very little heat is lost. Several new pits have been built, which are heated partly by linings of dung, and partly by pipes of hot water. The walls for peach trees are of brick, furnished with horizontal wires, strained tight by means of screws and nuts, to which the branches are tied, without the use of nails, and without injuring the walls. Other trees are trained to wires fixed in the form of semicircles; the lower part of the stem of the tree forming the centre, and the semicircular wires being placed about 18 in. apart. The appearance reminds us of Seymour's mode of training, but it has no other connexion with that mode than the general appearance of the semicircles intersected by the radiating branches. There is much in these gardens to observe and to commend.
