The _bark stove_ has a brick pit filled with tan or dead leaves in the centre; and it is generally heated with pipes of hot water or steam, from 60° at night to 80° in the day; the pots in which the plants are grown being either plunged in the tan, or placed on the walls of the pit, or on a stone shelf near the glass in front. Sometimes the trees of hot climates are grown in the bark bed in the centre without pots; and sometimes there is no bark pit, but the space in the centre of the house is filled with boxes containing tropical trees. This last kind is frequently called the botanic stove, as it is most common in botanic gardens; and it is best adapted for growing palms, and other monocotyledonous plants with large leaves, such as bananas, which require abundance of air and light. The _damp stove_, or orchideous house, is only suited for orchideous plants and exotic ferns. The heat should be from 70° at night to 90° in the day, or even more; and the house should be heated with hot flues, on which water should be thrown twice or three times a day, and hot-water pipes with open tanks; as all the plants to be grown in this kind of house require excessive heat and constant moisture. As they are also plants that love the shade, the house should have only a subdued light; and though I cannot say that I approve of the coloured glass adopted by some cultivators, as it decomposes the rays of light, and deprives the plants of a portion of the heat they would otherwise derive from the sun, yet I would certainly advise that some of those climbing plants which will grow in a moist warm climate should be trained close under the glass, to produce shade. _Forcing-houses_ for grapes and early stone fruits are of the nature of the bark stove; and in them the pit in the centre is frequently filled with pine-apple plants, in pots plunged up to the rim in the tan; but these houses belong to the kitchen-garden, as do pits for growing pines, cucumbers, and melons. You will thus observe that there are only three distinct kinds of hothouses in use in British gardens, viz. the damp stove, or orchideous house, which is the hottest; the dry stove, or house for succulent plants, which is the rarest; and the bark stove, which is the most common, and which may be said to have two varieties, viz. the botanic stove and the forcing-house. _The culture of hothouse plants_ in the _bark stove_ requires more care than can be expected from any one not a regular gardener; and, as most tropical plants are valuable in this country, I would not advise you to try to manage them yourself, as you would be very much vexed if you should chance to kill them. I will, however, give you a few general hints on the subject, if you should like to have a house of this kind.