26 Transactions of the Botanical and Horticultural Society 



country, where the cheapness of fuel leaves the hot-bed much 

 the more expensive department of a stove. From the result 

 of an experiment I made after Mr. Knight's suggestions, the 

 details of which I have given in an annexed paper, 1 have 

 little doubt it might be advantageously adopted ; but, in the 

 construction of a house for this purpose, the circumstance, 

 that die heat under glass increases with the distance from the 

 ground, should always be kept in view. Possibly, if any 

 method could be found of agitating, or, as it were, mixing the 

 enclosed air, it might counteract this tendency to an undue 

 accumulation of heat above the plants. The flue, probably^ 

 had best be made to traverse the house several times at a level 

 below the pots, but on no account must it be piled up against 

 the back wall ; which, in all cases, is evidently an injudicious 

 construction, throwing additional heat into a part of the house, 

 which, without it, has a tendency to exceed the rest in tem- 

 perature. Every part below the pots might be advantageously 

 painted black, to absorb and retain the heat below as much as 

 possible. The pots, of course, should be larger than those 

 xised at present, as the roots must be confined to them, and 

 derive all their nourishment from what they contain, no longer 

 having the bark-bed to shoot into when they have filled the 

 pots ; and as, without bottom heat, the plants receive a great 

 check, and are much retarded in their progress by being 

 shifted, they had probably best, as soon as well rooted in a hot- 

 bed, be at once removed into these large pots, and from time 

 to time earthed up as they increase in size, three or four inches 

 of the top being at first left empty for this purpose. Water 

 will also be most copiously required, as the power of evapor- 

 ation in so high a temperature will be very great when the 

 pots are totally exposed, as they will be in this case ; for it 

 can never be desirable, upon the above-mentioned principle, 

 to plunge them in sawdust, as has been proposed, or in any 

 other substance that is not itself a source of heat, or, in other 

 words, a hot-bed. 



" I have thrown together these hints in hopes they may be 

 the means of calling the attention of other members of our 

 Society to the same subject. The system seems more adapted 

 to, and more likely to prove advantageous in, this country, 

 where coals are abundant, than in situations less favoured in 

 that respect. I am not by any means so sanguine as its pro- 

 jectors, in supposing the culture will be thereby improved in 

 point of produce ; my utmost expectations being, that equal 

 success may be obtained at considerably less expense." 



