10 



THE PRACTICAL GARDENER. 



In this cistern are cultivated the p'oper plants, some rooting 

 in muddy rich soil placed on purpose in the bottom ; others 

 floating on the surface, which, like the genus Lemnay may be 

 said to have no settled place of abode. A flue goes round 

 underneath the bottom of the cistern, in order to keep the 

 water of a certain temperature; while another flue goes round 

 the house, for the purpose of heating the atmosphere of it : 

 the bottom of the cistern in question is of slate, supported on 

 iron bearers, over which is a covering of lead. Wood might 

 have been used, had no fear of danger from the heat of the 

 flues been apprehended. In a house of this description, the 

 tallest gi'owing aquatic plants might be exceedingly well culti- 

 vated ; but for those of diminutive growth, and such as float 

 only on the surface of the water, such as Nymphcca^ &c., a 

 house much less lofty, or indeed a neat pit would answer 

 much better, for experience proves, that such plants require 

 all the light and sun that it is possible to give them, and 

 which can never be so completely effected if they be placed 

 too far from the glass. Mr. Loudon, in The Encyclopedia 

 of Gardenitig^ proposes the following improvements in re- 

 gard to Tropical Aquariums : — A more perfect plan would 

 be (alluding to the house at White Knights) to have the 

 cistern close to the front glass, and to have that glass rather 

 flat, say an angle of 15 dcgi'ees ; or two cisterns might be 

 formed, one in the back part of the house for tall plants, and 

 the other in front for floating foliage, with a broad path be- 

 tween. But the most elegant plan would be," continues that 

 intelligent writer, " to have a circular house, glass on all sides, 

 to have a cistern in the centi'e for river plants, and a surround- 

 ing cistern for those which grow in stagnant water. To 

 imitate the effect of the motion of water, in the central cis- 

 tern, the mould, or pots in which the plants grow, might be 

 placed on a bottom apart from that of the cistern, and this 

 bottom being on the end of an upright shaft might, by the aid 

 of proper machinery, in a vault below, be kept in perpetual 

 circular motion. Those plants, which grow naturally in rapid 

 streams, might be planted or placed on the circumference of 

 the bottom, and those requiring less agitation towards its 

 centre. If reversed motion were required to imitate tides, 



