170 Mr. Waikins on conJlriiBing a Green- Houfe. - 



more of the rays are alfo introduced into the building, and 

 when the fun produces moft heat during the day, there is no 

 refledion of its rays, and at other parts of the day, the 

 refle£ling angle being obtufe, does not powerfully call off 

 the rays. The infide of the rafters of the roof, fhould be 

 lined with boards, and the fpace between that and the roof 

 filled with a mixture of ftraw, fand and clay made into mortar ; 

 boards fhould be ufed in preference to fliingles, as making 

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

 admiflion of cold air. The refidue of the building may be of 

 flone or brick work, or a frame building filled in with 

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

 Shutters on the outfide are fufficient, and it is preferable 

 to have them hung on hinges, as the leaft troublefome, to 

 the common praftice of Aiding ones ; they fliould be made 

 to fold into the fpaces between the windows.' 



Before putting the plants into the houfe, the bottom fliould' 

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

 according to the depth the building is funk in the earth. 



The advantages propofed by this method of conftructing 

 are, the leflening the expence of building, that the heat of 

 the fun being fufficient to warm the houfe, the trouble and 

 expence of warming it by a llove is avoided, which unlefs- 

 very carefully attended, the plants may be injured by too- 

 U'.uch heat, and are always by the fnioak that unavoidably: 



