ORCHIDS : HOW TO GROW THEM SUCCESSFULLY. 23 



can be set into the brickwork of a wall or of the house, or on the 

 ground level, thus saving the necessity of a stoke-hole. Some of these 

 are very good. 



For the Cool Orchid house there must be sufficient heat at command 

 to maintain during severe weather a night temperature averaging 45 

 degrees. For an Intermediate house there should be enough to keep 

 up a night temperature of 55 degrees ; whilst the temperature of the 

 Warm house should not be allowed to fall below 60 degrees for 

 any length of time. 



STOKING THE FIRES. 



As it is warmth from the pipes which creates the artificial 

 temperature in the greenhouse, and as Orchids are plants which 

 sustain themselves chiefly on air, it is quite evident that the better the 

 artificial air is produced and maintained the better it is for the Orchids, 

 as well as for other plants growing with them. Stoking, then, is an 

 important matter, and such work should be done by an intelligent 

 man, and not left to any person unaccustomed to such work, as is 

 too often the case. There is art even in stoking a greenhouse fire, 

 and the person who is in charge of the fires should understand the 

 thermometer, and be one who can be relied upon to give careful 

 attention to his duties, letting the conditions of the weather outside 

 guide him. Let us suppose, for instance, that it is a very dull and cold 

 day in January, when the fires require to be well stoked, keeping them 

 clear and bright, as can be done with anthracite coal or coke ; at such 

 a time more heat will be necessary during the day than at night, in 

 order to give a rise of a few degrees in the temperature. This is an 

 instance when careful stoking and watchfulness of the thermometer 

 crops up. Then suppose a day in March or April, clear and bright, 

 but very cold, necessitating good firing during the night to keep up a 

 proper temperature, but with the sun shining brightly in the daytime, 

 a much reduced amount of fire only would be wanted. The fire could 

 then be ''damped down" with slack (small coal) until two or three 

 o'clock in the afternoon, when it should be started again, first clearing 

 out the furnace bars and firehole. In the hot summer days of June to 

 August it is possible that fires may be dispensed with, even in the Stove 

 house, but still a cold day or night may come, when a little fire to warm 

 the pipes and raise the temperature a few degrees would be advan- 

 tageous. Again, in November, one day may be very cold, requiring 

 brisk fires to keep the proper temperature, whereas the following day 

 may be damp and close, needing but little warmth in the pipes, enough 

 only to assist ventilation and to admit of the ventilators being opened. 

 See, then, that the fire is managed carefully, always maintaining an 

 even temperature, avoiding the extremes of overheating and dryness, 

 or damp and cold. 



