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LXXVIIL On the Protection of the Blossoms of Wall 

 Trees. By Thomas Andrew Knight, Esq. F. R. S. $c. 



President. 



Read June 15, 1824. 



I n a climate so subject to sudden variation of temperature, 

 as that of Britain, in which a frosty night is often preceded 

 by a wet evening, and succeeded by a bright and warm 

 morning, the blossoms of almost every species of fruit tree 

 trained to a wall, usually set best under the protection 

 of some degree of covering. This seems to operate bene- 

 ficially in several different ways. It often prevents the blos- 

 soms being wetted, and thence renders them less subject 

 to injury from any moderate degree of cold. It diminishes 

 the radiation of heat from the wall during clear and cold 

 nights ; and it .prevents the sudden transition from a low to 

 a high temperature in warm and bright mornings : and the 

 sudden transition from low to high temperature is much 

 more fatal to vegetable, as it is to animal life, than an equally 

 sudden and equally violent transition from a high to a low 

 temperature. Even the blossoms of standard Fruit trees, 

 which are situated in their interior parts, when such trees 

 have been properly pruned, receive much protection from the 

 external branches, and not unfrequently escape destruction 

 from frost, when all those, which grow upon more exposed 

 branches, perish. Amongst the various of methods of protect- 

 ing the blossoms of Wall trees from frost, which are adopted 

 by gardeners, it must be admitted that the most efficient are 

 vol. v. 3 U 



