288 Centre Bed in a Hot-house heated hy hot Water. 



52 



"XT "in '^' 



h. Pipe from water casks outside, continued on at back of centre bed. 

 «, Small shoulders, soldered in, and stopcocks affixed. 



*, Copper tubes, which fit the shoulders, and are removable at pleasure. These are punc- 

 tured laterally, to disperse the water. 



bed, without an inch of space being lost ; and the moisture 

 is dispensed around and beneath them. Nothing can exceed 

 the health of the plants on this bed, which are chiefly seed- 

 lings and offsets of the Amaryllirf^*^, and certainly revel in 

 their situation. Suffused with a refreshing dew in the morn- 

 ing, they have continued to grow vigorously during the win- 

 ter, forcing their roots perpetually through the bottom of the 

 pots into the sand. I see nothing to prevent this principle 

 being applied to all the purposes for which moist heat is neces- 

 sary : to retain which in a lively state, without risk (not to say 

 a word of its annoyance and expense), costs the gardener 

 more trouble and anxiety than all his other avocations. The 

 apparatus has been at work since last autumn. It might be 

 necessary, where water is scarce, to have a more retentive 

 substratum than that which I have adopted, as in warm 

 weather the evaporation would, no doubt, be very consider- 

 able. The grand object is to preserve the moisture, without 

 which the whole plan would be futile. I cannot help ascrib- 

 ing the failure of the numerous schemes for attaining moist 

 bottom heat, except from fermenting matter, to the capri- 

 cious and partial application of the means adopted to produce 

 and maintain the moisture. The thing is either overdone or 

 not done at all ; hence we have baking in one spot and damp 

 chill in another : but by means of these tubes the water, from 

 its pressure from without, is dispensed evenly throughout 

 the bed, and that without further trouble than turning a 

 stopcock. 



