GEA 



[448 ] 



GEE 



walk has been broken up and levelled, 

 and a facing of new gravel spread over, 

 tbis ought to be left for three or four 

 days, and until a shower of rain has 

 fallen, before the roller is used. This 

 bleaches the gravel, and washes down 

 the fine particles, so that, immediately 

 after rolling, the walk is solid, and has 

 a clean bright surface. 



The above directions relate to the old 

 system of gravel-walk making, but we 

 strongly recommend the general adop- 

 tion of Concrete Walks, which see. They 

 are far more durable, and free from 

 weeds. 



GREAT BURNET. Sanyuiso'rba. 



GREAT CENTAU'REA. Centau'rea cen~ 

 tau'rinm. 



GREENHOUSE .-rThis is a light airy 

 structure designed for plants which 

 can sustain a lowish temperature, but 

 cannot withstand the vicissitudes from 

 frost to sunshine, and from damp to 

 dry, of our common winters. It is dis- 

 tinguished from a plant stove in re- 

 quiring but little artificial heat ; and 

 from a conservatory in having all the 

 plants (with, perhaps, the exception of 

 climbers for the rafters) grown in 

 portable pots or tubs, and these gene- 

 rally set upon a stage to bring them 

 nearer the glass. 



The mode of constructing such a 

 house must be regulated by the wishes 

 of the proprietor, and the conveniences- 

 at his disposal. For general purposes 

 any aspect will do in an emergency, 

 except the north, and that raigbt be 

 selected for those plants that cfeiight 

 in the shade. The more command of 

 light, with the means at hand of re- 

 ducing its fierceness and heat when 

 too powerful, the better. From due 

 south to south-east and south-west, 

 may be considered the best aspects. If 

 it is a lean-to house, having a sloping 

 roof from a back wall, it should always 

 have a considerable amount of upright 

 glass in front to receive 11 ie oblique 

 rays of the sun in winter. By the side 

 of a cottage ornee the front of the 

 house may thus partake of the same 

 style of architecture, while the shed- 

 like sloping roof may be exchanged for 

 u ridge and furrow one, and that con- 

 cealed from external observation by a 



light entablature or frie/e work. For 

 a neat detached structure it should 

 ! stand, less or more, north and south, 

 j have a ridge and furrow roof, and 

 | means for breaking the sun's rays in 

 the morning and afternoon. We are 

 supposing it to bo glass all round. 

 When in connection with other build- 

 j ings a very useful and elegant house is 

 formed, having the front and ends of 

 glass, a hipped roof, and an opaque 

 back wall. Here, likewise, by an orna- 

 mental entablature, the roof, if desir- 

 able, may be wholly or partially con- 

 cealed, so as not to interfere with archi- 

 tectural propriety, though we should 

 have no great scruples on this score, as 

 the utility of an object, if apparent, 

 gives it appropriateness. 



The size of the glass to be used 

 must depend upon the taste and the 

 money wished to be spent by the pro- 

 prietor. For the roof, especially, it 

 will be desirable to have it at least 

 sixteen ounces to the foot. Small 

 squares can be procured in boxes very 

 cheap, but what you gain in glass you 

 partly lose from requiring so many 

 sash-bars. We should not care about 

 having them much above eighteen 

 inches in length. All things considered, 

 if we were to roof a house most econo- 

 mically, we should obtain strong ma- 

 chinery-cut sash-bars, dispense with 

 rafters, use glass from fifteen to eigh- 

 teen inches wide, and say a foot in 

 depth, and secure means of ventilation 

 without touching the roof, by means of 

 the upright glass, and wooden venti- 

 lators at the ridge in the roof, and in 

 the back wall. 



Slayes. These are generally shelves, 

 arranged in stair-like fashion, partaking 

 less or more of the character of the 

 roof. For a general collection, the 

 stage may be from five to six feet from 

 the glass roof; for insuring dwarf, 

 compact, bushy plants, the distance 

 should be from three to four feet. The 

 lowest shelf of the stage should be a 

 little higher than the shelf that sur- 

 rounds the house next the front glass. 

 Where the roof is Itiji/u'd, even though 

 the back wall be opaqiie, if the house 

 faces the south the stage should b<-. 

 hipped too, terminating in a single 



