MANAGEMENT OF THE ATMOSPHERE. 



291 



hot-house. Those houses whose internal bases are composed 

 of open soil require less ventilation than those that are paved 

 with stone or tiles ; and those that are paved with tiles, or other 

 soft materials, reqaiie less than those formed of hard and highly 

 reflecting bodies ; dark-colored walls, also, are longer in raising 

 the temperature of houses than walls painted white, and for this 

 reason white is preferred to any other color, as well as for its 

 clean and light appearance when contrasted with the dark-green 

 foliage of the plants. But in houses that are perfectly transpa- 

 rent on every side, and admit abundance of light, there is no 

 reason to suppose a dark color would not be preferable to a light 

 one, although we are well aware that some scruples may be 

 raised against it. Its propriety, however, can only be ques- 

 tioned as a matter of taste, not of utility ; for, with the advan- 

 tages above alluded to, in a well-constructed green-house, so far 

 as the management of its atmosphere is concerned, we would 

 decidedly prefer a house having the interior painted with a dark 

 color, although we are very sensible that the effect produced 

 would be meagre and dull, and but little calculated to harmo- 

 nize with the floral inhabitants of the house, or the feelings of 

 those who admire them. 



Fig. 58. 



6. The above cut represents a house ventilated by the com- 

 mon method, i. e., the upright sashes at the sides and the top 

 gashes along the roof, which, in span-framed houses, are gener- 

 ally about four feet long, or nearly square. In summer this 

 ■nethod answers perfectly ; but in winter and early sp''ing it is 



