152 



GREEN-HOUSE. 



taken of glazing as much of the eastern end as possible, 

 for the benefit of the morning sun. The front should de- 

 cline northward from a perpendicular with the horizon, so 

 as the angle made thereby with the horizon will, at noon- 

 day in winter, bring the rays of the sun to strike the glass at 

 right angles, and the roof should descend the opposite side 

 without a break. By this position of the roof and glass, the 

 rays of the sun are thrown upon every part of the inside of 

 the house, and the whole becomes heated thereby ; more of 

 the rays are also introduced into the building, and when the 

 sun produces most heat during the day, there is no reflec- 

 tion of its rays, and at other parts of the day, the reflecting 

 angle, being obtuse, does not powerfully cast ofl' the rays. 

 The inside of the rafters of the roof should be lined with 

 boards, and the space between that and the roof filled with 

 a mixture of straw, sand, and clay, made into mortar ; 

 boards should be used in preference to shingles, as, making 

 fewer breaks in the roof, less opportunity is given for the 

 admission of cold air. The residue of the building may 

 be of stone or brick work, or a frame building filled in 

 with bricks, and no flooring of any kind upon the ground. 

 Shutters on the outside are sufficient; and it is preferable to 

 have them hung on hinges, as the least troublesome, to the 

 common practice of sliding ones : they should be made to 

 fold into the spaces between the windows. 



" Before putting the plants "into the house, the bottom 

 should be covered with bark from a tan-vat, about a foot 

 deep, according to the depth the building is sunk in the 

 earth. 



" The advantages proposed by this method of constructing 

 are, the lessening the expense of building ; that, the heat of 

 the sun being sufficient to warm the house, the trouble and 

 expense of warming it by a stove is avoided, which unless 

 very carefully attended, the plants may be injured by too 

 much heat, and are always by the smoke that unavoidably 

 makes its way out of the pipes. It would be proper, nev- 

 ertheless, to make arrangements in constructing the house 

 for using a stove, in case a long succession of cold, cloudy 

 days, by obscuring the sun, should reduce the heat in the 

 house below that degree of temperature necessary for pre- 

 serving the plants, w^hich is a case that will seldom hap- 

 pen, as one clear day will warm the house sufficiently to 

 admit its being shut up for several days. 



" Plants in a house of this kind require less water, and do 

 not sufler for the want of atmospheric air. It is probable, 



