2i8 TJie OrcJiid-Hoiise. 



A brick flue may be used for heating with pans placed on the top for 

 the evaporation of water ; but care must be taken to prevent any escape of 

 smoke or gas into the house. 



Ventilation and Temperature. — A careful system of ventilation is of 

 great importance. Let us bestow every care upon orchids, all will be in 

 vain if we allow cold air to pass among them : the plants will not thrive. 

 Ventilators should, therefore, be provided near the ground in the front wall, 

 close to the heating-pipes, so that the air may be warmed as it enters the 

 house : they may also be constructed in the brick-work at the north and 

 south ends. These ventilating spaces may be closed by wooden shutters 

 or by sliding slates : they should be two feet long and one foot wide, and 

 should be left every twenty feet. If the house is span-roofed, they should 

 be on each side. 



If the top-lights are made to slide, any ventilation desired may be easily 

 afforded ; but, if not, ventilators should be placed in the ends of the house, 

 near the roof : but, even with sliding sashes, the ventilators on the front 

 must not be dispensed with. 



The temperature should be about fifty degrees in the coldest weather : 

 if allowed to fall much lower, the plants will be chilled. During the season 

 of rest, — which with most orchids is from November to February, — the 

 temperature should not be much higher. This season of rest is essential to 

 the production of a strong growth and fine flower. 



If the same heat is always maintained, and constant moisture afforded, 

 the plants will continue growing, or will produce weak second-growths, and 

 either fail to flower, or else produce weak and few blossoms. 



A most ready way to secure this rest is to remove the East-Indian or- 

 chids to the cooler or Mexican house during their resting season, — that is, 

 after they have perfected their growth, — and again to remove the Mexican 

 orchids to the greenhouse during their resting season. 



There are some East-Indian orchids, such as Phalcenopsis and yEredis, 

 which grow perpetually : these should always be kept in the hottest house; 

 but the heat s'.iould be somewhat reduced, lest the plants be forced into too 

 active growdi or bloom, as these plants often kill themselves by over 

 flowering. 



