100 THE GREEN-HOUSE. [JAN. 



of hot-bed lights, the remainder being either covered with slate or 

 shingles and tarpaulins, or very strong canvas fixed on rollers, to be 

 let down over the roof-glasses in very severe weather ; you may also 

 have large canvas cloths upon rollers to let down occasionally be- 

 fore the windows, or in default of such, you may nail up garden 

 mats. 



Let one-third of the front side of the roof, for the whole length of 

 the house, be formed of glass-work, and the back wall raised, so as 

 that a horizontal ceiling may be carried from the upper part of these 

 lights to it, which will cause the back half of the roof to be some- 

 what more flat than the front. Ornamental wood- work may be erected 

 outside along the top of those lights to give a light appearance to the 

 roof. Or, if the house be small, you may carry the entire roof with 

 a gentle slope from the front to the back wall, which must be made 

 of a proper height for that purpose ; one-third or one-half of such 

 roof may be made of glass-work, from the termination of which carry 

 the ceiling on a level to the back part of the house. 



The better to confine the air warmed by the sun in the day-time, 

 and to prevent the cold air from rushing in on the approach of night, 

 when that within begins to cool, and consequently to contract in bulk, 

 I would advise to have ail the panes in the roof-lights neatly and 

 closely puttied where they overlap one-another; and to have either 

 one, two or three of those lights, in proportion to the length of the 

 house, so constructed, as to slide down and up a few feet by means 

 of pulleys, in order to give vent to the foul air generated in the house, 

 which naturally ascends to the upper part. The sized glass, recom- 

 mended in page 11, for hot-bed lights, is what I would particularly 

 recommend for these roof-lights, being not only the strongest but by 

 much the cheapest. 



The windows, or upright front-lights, must be made with large 

 panes of glass, &c., to admit the more light, as well as to give a hand- 

 some appearance to the house , the upper half of each window must 

 be so contrived as to slide down, and the lower half up occasionally, 

 to admit air to the plants when necessary. 



If a spacious and ornamental window be placed in each end (if 

 the house be detached), to receive the benefit of the rising and set- 

 ting sun, it will be of considerable advantage ; these particularly 

 should have good close shutters either inside or outside, and be kept 

 shut every night during the winter, and also in the day-time in very 

 severe weather, except while the sun immediately shines on them. 

 If the front is so contrived that inside shutters to the windows can- 

 not be conveniently hung, outside sliding shutters should be made to 

 be used only when necessity requires. 



But let it be particularly observed, that all the lights, cases, doors, 

 and wood-work of the house be made of good seasoned wood, and 

 well painted, to prevent either their swelling by wet or shrinking by 

 drought; that all parts be well jointed and fitted together, so as to be 

 as nearly air-tight as possible. 



A house constructed on this plan will very seldom require the as- 

 sistance of fire-heat, which ought always to be used with great caution 



