By Mr. Henry Stothert. 



199 



The vapour is so completely arrested by the strata of stones, &c. 

 and sand, beneath the pots as to communicate a heat congenial 

 with the health of the plants without the least excess of moisture. 



For Melon Pits, fyc. 



Fig. 5, Plate 7, represents a mode of applying bottom-heat to a 

 Melon Pit, adopted by Mr. Sturge of Bath. In this arrangement, 

 a hollow chamber is formed over the bed of stones, &c. that cover 

 the steam-pipes, the arrangement of the paved bottom, steam- 

 pipes, channels, &c. being in all respects similar to that described 

 in Fig. 3 and 4. Immediately over the bed of stones are laid 

 joists, supporting a paved bottom jointed without mortar, on which 

 is placed another bed of stones, &c. about eight inches thick, and 

 on this the mould containing the plants. 



The objects of this arrangement are first to obtain a perfect uni- 

 formity of temperature, and secondly, to prevent the possibility of 

 any of the roots receiving injury from heat, should they accidentally 

 strike through the mould into the bed of stones ; both of which 

 objects are perfectly attained. 



Fig. 7 and 8 represent an elevation and plan of a Melon Pit 

 erected for W. W. Salmon, Esq. at Devises, shewing also the 

 mode of heating the atmosphere of the pit, (which will be explained 

 hereafter) the arrangement of the steam-pipes, paved bottom chan- 

 nels for vapour. &c. are precisely the same as above described, but, 

 in lieu of the bed of broken stones, &c., bricks are here placed 

 edge-wise one over the other four deep, arranged in the same 

 manner as for burning a kiln, over which is laid a flat cover jointed 

 close without mortar, and on this the mould containing the plants. 



For Aquatic Plants. 

 Fig. 6, Plate 7, shews a mode of warming a cistern or reservoir 

 of water for the preservation of Aquatic Plants, as erected at Mr. 



