as practised at Do*wnton Castle. 369 



time will be found to preponderate greatly in favour of Mr. 

 Knight's. I am aware that the plunging of the pots is essential 

 to the successful cultivation of the pine in the usual way ; and as 

 the gardener's avocation claims his attention every where, the 

 less he becomes dependent on the cooperation of others, the 

 more sure his success will be. By continuing the pot-plunging 

 system, the plants will be less likely to suffer from the negligence 

 of assistants, or from the sudden changes of the weather ; and 

 this system would certainly be the best, if any means could be 

 devised to obviate the necessity for the continual renewing of 

 the tan-bed, or the shifting of the plants, except at the time of 

 replenishing the bed with a fresh supply to produce another 

 crop of fruit ; and if this plan could be combined with Mr. 

 Knight's mode, it would materially lessen the labour and expense 

 now required. 



Mr. Hay's (of Edinburgh) method of communicating heat to 

 the body of the bed is the best, I think, yet made known to the 

 public : still it is objectionable ; and, during my late journey 

 into the country, I saw an instance of its injurious ejfipects arising 

 from the negligence of the person who was inti'usted to turn the 

 steam off the pine-bed, and who forgot to do so at the specified 

 time ; the consequence was, that the roots of all the plants that 

 were plunged on that division were completely broiled. The 

 agency of any thing that is subject to such sudden effects should, 

 I think, rarely be employed, particularly where the success 

 depends so much upon the precision of personal attendance ; and 

 the improved state to which the hot-water system is brought 

 leaves no ingenious gardener at a loss for a safe and effectual mode 

 of heating; but in this, as in almost every other new discovery, 

 a multiplicity of modifications under the name of improvements 

 are brought forward by individuals claiming public patronage, 

 which may tend to disconcert the young gardener in determin- 

 ing to which he should give the preference. I would here 

 remark that the most simple in its construction will generally 

 prove the most effectual in its operation, provided it is suitable 

 to accomplish the purpose required; and, of all the systems that 

 I have seen, I give the preference to Kewley's siphon mode of 

 circulating hot water, it being governed by atmospheric pressure. 

 A common open boiler, or, in fact, any vessel that will stand 

 fire heat, and is large enough to hold ten gallons of water and 

 upwards, will do ; and, as the merely placing the ends of the 

 siphon pipes in a perpendicular direction, a few inches beneath 

 the surface of the water, is all that is necessary, there is no diffi- 

 culty or trouble in adjusting them to any hot-house, however 

 unfavourable its position may be : and, in addition to this, it 

 has the peculiar advantage of admitting water, without delaying 

 its operation, to circulate on a level with the boiler in open con- 



