VENTILATION. 27 



VENTILATION. 



Upon the manner in which fresh air is admitted 

 to forcing and other glass-houses where plants 

 are being cultivated depends in a great measure 

 the success or otherwise that may be achieved 

 by the cultivator. It must be borne in mind that 

 fresh air should be admitted to the individual glass- 

 houses to prevent the temperature from rising above 

 the desired degree of heat, and not, as is sometimes 

 the case, to lower it bearing in mind also that a 

 superabundance of fresh air being admitted at one 

 time will not make up for a deficiency of this 

 essential element to good health at another time, 

 On the contrary, the quantity of air given in the 

 early part of the day should be increased and de- 

 creased in accordance with the rise and fall of the 

 internal temperature until closing time in the after- 

 noon arrives. Plenty of moisture should be dis- 

 tributed in the forcing-house, in order to promote 

 and maintain a clean, healthy, rapid, yet sturdy 

 growth in the peach trees, the judicious circulation 

 of fresh air during the heat of the day tending to 

 induce a short-jointed, consolidated growth, instead 

 of the long-jointed, sappy growth which invari- 

 ably results when trees and plants are grown 

 in a close atmosphere surcharged with moisture. 

 In the case of late peaches, it is a good practice 



