816 



PRACTICE OF GARDENING. 



FART III. 



6177. The bark or moist stove differs from the last only in having a pit (Jig. 573. 4) for 

 bark or other fermenting matter instead of a stage. This pit may be from two and a 

 half to four feet deep, according as bark or leaves are to be used, the latter material 

 requiring the greatest depth. It is commonly surrounded by a thin brick wall, but, in 

 elegant structures, planks of stone, or plates of slate or cast-iron, are to be preferred, 

 as a higher finish, and occupying less space. The roof, when 

 necessary, may be supported from the iron columns from the LJ^^ ,574 



middle of the pit. (Jig- 574. a) Shelves may be placed against 

 the back wall (6), and occasionally a narrow-leaved creeper run up 

 the roof (c). Such is the common interior arrangement of a 

 botanic stove, as may be exemplified in that designed by Alton, 

 and erected by Todd, in the royal garden at Frogmore. (Jig. 573.) 

 We may add, that houses of this description are generally placed 

 east and west against walls, on account of the shelter thereby ob- 

 tained during winter, when a high degree of heat is kept up 

 within, while the cold is excessive without. There are exceptions, however, in the 

 plant-stoves of the more recent public botanic gardens, especially those of Dublin and 

 Liverpool, which are placed with their ends to the south, and in the immense palm-house 

 erected by Messrs. Loddiges, which stands east and west, and is glazed on all sides. In 

 private flower-gardens the hot-houses frequently consist of a range (Jig. 575. ) containing 



575 



a green-house (a) at one end, a dry-stove (b) at the other, and a stove (c) in the centre. 

 By this disposition the stove is easier kept up to the required temperature, though it loses 

 the full influence of the light at the ends. In general, a stove requires double the num- 

 ber of fires required to a green-house of the same size. 



6178. There is a peculiarity in the construction of plant -stoves which deserves particularly to be noticed ; 

 namely, that fewer openings for the admission of air are requisite than in any other hot-house, excepting 

 the pine-stove. One reason of this is, that the degree of heat which must at all times be kept up in the 

 enclosed atmosphere, is so much greater than that of the open air, that the difference in the specific gravity 

 of the two fluids, when permitted to mingle by opening two or three sashes, produces a more active circul- 

 ation, and sooner approaches to an equilibrium of temperature : another is, that however numerous the 

 openings in the hot-house roof may be, they could seldom be made use of without reducing the house to 

 too low a temperature ; and a third and last is, that the plants being mostly kept in pots, and many of 

 them, as the palms, being of slow growth, they are not so apt to etiolate as those of the green -house and 

 conservatory. Hence it is, that the roof of a botanic stove may generally be erected at less cost than that 

 of a green-house or conservatory ; but particularly where iron is employed, and the curvilinear principle 

 adopted. 



6179. Houses of magnificent forms, and almost as light within as in the open day, might 

 thus be constructed for the growth of palms, scitamineae, bamboos, and other tropical trees 

 to be planted in the ground, as in the conservatory. These might also be detached in the 

 flower-garden (as Jigs. 10. and 20. in Sketches for Curvilinear Hot-houses), or they might 

 form an appropriate appendage to a palace in the oriental style. (Jig. 576.) Indeed, 



there is hardly any limit to the extent to which this sort of light roof might be carried ; 

 several acres, even a whole country residence, where the extent was moderate, might be 

 covered in this way, by the use of hollow cast-iron columns as props, which might serve 

 also as conduits for the water which fell on the roof. Internal showers might be produced 

 in Loddiges' manner ; or the roof might be of the polyprosopic kind, and opened at 

 pleasure to admit the natural rain. Any required temperature might be kept up by the 

 use of concealed tubes of steam, and regulated by the apparatus of Kewley. Ventilation 

 also would be effected by the same machine. The plan of such a roof might either be 

 flat ridges running north and south (Jig. 577. a), or octagonal or hexagonal cones (6), with 



