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little air and kept very high temperatures, especially 

 when much solar light existed. By these means he 

 obtained just what exists in nature — an advantage of 

 a few degrees in the average of the bottom-heat over 

 that of the atmosphere. Therefore, it appears Mr. 

 Knight did not deny the propriety of bottom-heat, 

 but merely the capricious means by which it is gene- 

 rally obtained. Mr. Hamilton, after long practice, 

 during which he has met with extraordinary success, 

 also approves of what is termed a very moderate 

 amount of bottom-heat ; about 80 degs. in the sum- 

 mer, and not much more than 70 degs. in the winter. 

 Now, when we consider that an advantage of from 2 

 to 5 degs. exists in nature, in favour of the average 

 temperature of the soil, as compared with the atmos- 

 phere ; and that the average atmospheric temperature 

 for pines in a growing state, under glass in Bicton, is 

 something like 70 to 75 degs., or even 80 degs., we 

 must come to the conclusion that Mr. Hamilton's 

 practice is perfectly natural. (Gard. Chron. 1846, 

 726.) 



We may as well detail here Mr. Knight's course 

 of culture, without bottom heat, as practised at 

 Downton : — 



The suckers were put into pots of somewhat more 

 than a foot in diameter, in a compost made of thin 

 green turf, recently taken from a river side, chopped 

 very small, and pressed closely, whilst wet, into the 



