68 COMMERCIAL ROSE CULTURE 



Ventilating is an operation so simple, and yet so important, 

 that special mention should be made of it. In the first place, 

 sudden changes should be avoided. In Midsummer the houses 

 are wide open at the top and often the end doors are open, in 

 addition to side ventilation in very wide houses. And yet there 

 is not a night in the hottest weather when this air is not re- 

 duced, commencing to reduce earlier in the afternoon and to 

 increase later in the morning as the cool weather approaches. 

 There is no set time for this. A cold storm may come in Mid- 

 summer, making it imperative to reduce air and start the fires, 

 but, as a rule, the transition is gradual and almost imperceptible, 

 like the changing seasons. 



Some air is left on all night, excepting in the cold Winter 

 months. When three or four 1^4 -inch steam pipes will not 

 keep up the required temperature in a house 32 feet wide, the 

 night man closes the house for a few hours; and it is the same 

 with houses 50 to 60 feet wide, if five pipes, or six at the most, 

 will not keep up the warmth. In warm weather, in Spring and 

 Fall, the steam is turned on as soon as the temperature com- 

 mences to fall, which is between 8 p.m. and midnight, according 

 to the season, and left on a few hours, when it is taken off 

 and turned on again in the early morning, about daylight, for 

 two hours more should it have been too warm to keep up the 

 heat all night. 



We always keep one or two pipes painted with sulphur and 

 use these at this time of the year. In the Winter, little air 

 can be given, but in the Spring, as the sun gets stronger, it is 

 most important to commence to ventilate early. A good 

 grower will anticipate the changing temperature, the object 

 of which is to increase the amount of air without lowering the 

 temperature in the houses. Increase the air little and often, 

 and let the rise be gradual from sunrise to noon; the fall from 

 noon to sunset to be along the same line. 



Always avoid draughts when ventilating. Where the house 



