14 



ROYAL HORTICULTURAL SOCIETY. 



manure. I was also greatly surprised to find that there was no 

 tendency to dryness where the soil rested on the tiles. The drying- 

 process merely went on by evaporation at the surface, whilst the 

 moisture steadily increased towards the bottom. 



The floor being the heating power, it is also of importance to 

 know how much of it (inside the house) may be covered with 

 earth for plunging or growing plants, without too great a sacri- 

 fice of upper heat. I accordingly constructed temporary borders, 

 enclosed by slabs of wood, before making the permanent arrange- 

 ments, to try what the house would bear ; and I think I may 

 safely say that the half may be covered. I have gone nearly as 

 far as this, without apparently reaching the limit, for general 

 purposes ; but of course much will depend, in this respect, upon 

 the precise purpose to which any particular house may be 

 applied. In some cases more upper heat will be required than 

 in others*. I had at first intended trying experiments on the 

 effect of bottom-heat upon the roots of vines; bat, after I had 

 finished my house, I found that Lord Eversley had fully ascer- 

 tained, by four years' experience, the beneficial results of heat in- 

 troduced under his vine-border in very nearly the same manner. 

 He had, in fact, made a chamber by means of tiles about 2 feet 

 square, and had admitted under it the surplus heat of a pine-pit. 

 The earth in a severe winter was never under 60°, and the vines 

 throve admirably. Finding this point so fully decided, I have 

 turned my attention to other things. I have tried Trench beans, 

 early strawberries, tomatoes a, tige raide, and early carrots ; also 

 mustard and cress and radishes sown in January (and eaten in 

 February) in the outer border. Inside the house I have forced 

 French beans, asparagus, rhubarb ; and am trying, with every pro- 

 mise of success, figs, peaches and nectarines, vines in pots, and 

 delicate varieties of oranges, and also a bed of pines which took 

 extremely well. I ripened capsicums of different kinds, and have 

 supjnied the house with several of the ordinary kinds of flowers. 

 My house has been inspected both by scientific and practical 

 men, and they express a very favourable opinion of i^s utility. 

 For myself, I am a mechanic, and not a gardener. I am satisfied 



* If a greater amount of top-heat should be required, it may be obtained by 

 making the bottom of the borders higher than the general level of the floor. f 

 the borders be 4 feet wide, and the bottom be raised 2 feet on their side 

 walls, there will be 4 feet of surface capable of radiating heat from the side 

 walls instead of the floor, and nearly or quite as large a quantity of heat will be 

 given out, whilst the plants will be so much nearer to the glass. 



