CULTURE UNDER GLASS. 237 



still be hidden till it appeared on their plates, a thing of shreds and 

 patches. For open-air fStes and garden parties what more novel or 

 delightfnl mode of serving peaches and such like beautiful and delicate 

 fruits, than for the yonngest ladies to be furnished with the preHy 

 baskets full of peaches for distribution P Who could doubt the genuine 

 favons with which such a method of serving would be received f 



Culture under Glass. 



The great use of glass is to render the cultivator independent of climate. 

 It is, therefore, impossible to exaggerate its influence or importance in 

 horticulture. It enables capital and skill to defy outward conditions, 

 and to grow the plants and fruits of the Tropics in temperate or even 

 Arctic climes. To illustrate the importance of glass in peach culture, it 

 is only needful to note how generally of late years the rigours of our 

 harsh springs have blighted all prospects of fruit, and left trees in u 

 crippled, half dead condition. It must, however, be admitted that glass 

 alone is not sufficient to protect peaches against the rigours of our springs . 

 The glass must either be occasionally covered with frost-proof materials, 

 or the heat of the inclosed atmosphere must be added to on all occasions 

 -when the external air sinks to 22deg. or 24deg. Fahr. Peaches in flower 

 cannot be exposed to more than Sdeg. of frost with impunity, and the 

 resisting powers of glass against continuous frost must not be 

 reckoned at more than Sdeg. more. This is a popular but hardly 

 a correct way of putting the matter. For it must be obvious to 

 anyone who will give a, moment's reflection to the subject, that the 

 resisting power of glass is weU-nigh nil. The heat of the sun, 

 the cold of the open sky, alike pass freely through glass, leaving little of 

 either behind in its substance. The potency of glass as a conserver of 

 heat arises from its power of inclosing a body of air. That air is of 

 superior temperature to the general atmosphere. It follows that the 

 resisting power of glass houses will depend upon such considerations as 

 these : The size of the house, or rather its depth, that is, the number of 

 cubic feet of air for each foot of radiating and conducting surface ; the 

 disparity between the temperature of the outside atmosphere and the 

 internal air ; the duration of that disparity ; the freedom or otherwise 

 of the exchanges of heat between the two, and whether or not any 

 internal source of heat is available to counteract the loss by radiation 



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