366 WINDOW-GARDENING 



subjected to great variations of temperature. If possible, the 

 variation sbould be gradual, the atmosphere of the room becoming 

 cooler as the daylight fades, and remaining cooler thiough the 

 night, becoming warmer on the return of daylight, and warmest 

 when the sun is shining in through the window. The night 

 temperature should not be colder than 40° of Fahrenheit, and the 

 thermometer should not be kept above 70° by day, except while 

 the sun is shining into the room. It is better that the room 

 should be one not usually occupied by the family in the evening, 

 for at night we draw the curtains, stir up the fire, light the lamps 

 or the gas, and usually increase the temperature several degrees 

 above the average temperature of the day. But plants require 

 that when the daylight fades the temperature should decline. 

 Mght is their time for rest, but they cannot rest if the tempera- 

 ture be kept as high or higher than it was during the day. The 

 effect of such uimatural excitement upon plants is similar to that 

 produced upon a human being by depriving him of his wonted 

 sleep. 



It is better that the room should be one that is not heated by 

 a furnace. The air from furnaces is apt to be too dry and too 

 hot. If it must be heated by a furnace, set a paU of water in 

 the register, and at night shut off the heat so that the tempera- 

 ture may fall gradually to about 45° before morning. 



Gas-lighted rooms are bad for plants. Enough gas escapes in 

 the evening, unconsumed, though the flame may seem to be per- 

 fect, to kill delicate plants, and to injure materially the most 

 tobust. K they can not be kept out of such an atmosphere by 

 closing a glazed door or sash, so as to shut them out from the air 

 of the room, it would be better not to attempt their cultivation 

 at all. In most houses the kitchen is the room in which plants 

 will grow best. There they have a moist atmosphere, sufBcient 

 warmth by day, and cool temperature at night. Arrangements 

 should be made for conveniently giving fresh air to the plants 

 every day. The most convenient way is to have the upper sash 

 moveable, and to let it down at the top when we wish to give 



