GLASS. 



Buildings ot this kind may be coiiftrudled, occafionally, 

 cither againft fome ready-built fouth wall, which ferves for 

 the back, all the other parts forward being wood-work and 

 gUifs ; or detached in a hinilar fituation, fo as that tlie 

 whole front may fland to the fouth ; the back being framed 

 of brick-work, &c. or of wood double planked ; but tlic 

 former is preferable ; the whole being generally ranged 

 lengthways, nearly in an eall and weft direction. 



The dimenfions may be from iive or fix, to eight or ten 

 Kt't in width, by ton, fifteen, or twenty feet in length or 

 i-ore, as may be required ; and from fix or eight, to ten 

 : ift high behind, by five or fix to feven or eight in the 

 iVout, both ends in proportion with thetop, floping graduallv, 

 ns juil noticed, from th.e back, having an entrance, or door, 

 l:i front, or at one end. The glafs-work (hould be made to 

 i:iJe readily backwards and forwai'ds. 



Sometimes fire-fiues are carried along the back and front 

 ii.ternallv, proceeding from an external fuL-iiace, for occa- 

 i:..nal iire-lieat in winter, which i-euder the.n more conve- 

 ii'nt and ufeful for different purpofes. 



Thefe cafes, as mentioned above, are ufed as prefervatory 

 1, ;;artments, in which to winter many forts ot curious 

 exotics of the hardier grcen-houfe kind.;, which only want 

 protetlion from fevere cold, as well as many choice kinds of 

 the open ground, whicli are rather tenderilh in their minor 

 r.-owth, or any other particular or curious hardy plants, 



liether flowers, (hrubs, or young trees, efpecially the choice 



i.-r>Treen kinds, which require efFeclual protedlion from 



c ravages of rigorous frofts or cutting winds, in winter 

 1 early fpring ; and, at the fame time, in mild open 

 •v, eather, to enjoy the full air by opi-ning the glafles ; all 

 u iiich, being iu pots, can be readily placed in this prefer- 

 vatory at the approach of fevere weather, and be thus kept 

 in o-ood condition till fettled weather in fpring, Sec. ; then 

 removed into tlie full air. In fummer and autumn, when 

 unoccupied in this way, thefe cafes may be of fome utility 

 to place fome curious kinds of tender plants in, when in 

 fljwer for feeding, to guard them from heavy or inceffant 

 r.in, or cold night dews in autumn, wliich, in many forts 

 retard, or fometimes wholly frullrate their production of 

 cuod feed, as in many forts of curious tender annuals ; par- 

 ticularly the fine double bdfams, cock's-combs, tricolors, 

 double ftramoniums, diamond iicoides, and various others. 



They are alfo capable of being ufed in fpring and the 

 early part of fummer, as in April, May, and June, as a kind 

 of drawing-frames, for fome particular forts of curious 

 eanuals to bring them to a tall growth, fuch as the large 

 rr giant cock's-combs, tricolors, double ftramoniums, 

 (1, u >Ie-rtriped balfams, egg-plants. Sec. the plants being 

 nrft raifed in hot-beds, under garden-frames, till of twelve 

 or fifteen inches growth, then a hot-bed made in the glafs- 

 cafe, earthed at top, and the plants in pots, fingly plunged 

 into the earth of it ; the glalTes, in thefe cafes, lliould be 

 Ihut clofe, only a neceiTary admifllon of freili air beif.g given 

 < .ery day, by which they run up to a tall ftature in the beft 

 pirfeCtion of ftrength for flowering. See Annual Plantj;. 



Tiiefe forts of jrhifs-cafes are alfo fometimes made ufe of 

 r.-; a kind of appi'.rtenances to hot-lioufes, or ftcves, detached 

 from them, haviiig, as obferved above, internal flues for fu'e- 

 ::• at, when uecciTary, ferviiig as prefervatori.'S for many forts 

 I f exotics, whicii are tenderer than common greenhoufe 

 •^^:::its, but do not require the conftant full heat of the more 

 t iider hot-houfc kinds, but only the affiftance of moderate 

 iire-heat in winter, in cold nights, or when very damp, 

 t.oudy, foggy-weather and fevere frofts prevail. They are 

 iomctimes uied ia the bufinefs of forcing different kinds 



of flowering plants and efculcnts, either by means of an 

 internal bark-bed, or flues for firc-lieat. 



When intended for this purpofe, it is convenient to have 

 both an internal pit for a bark-bed, and flues for firc-heat 

 m order to ufe either feparalely, or fometimes both, as may 

 be fimnd neceflary. See Hot-Hou.se. 



Gi.xss-Fnces, m Mining, is a term for the polifticd fur- 

 faces, or fllckcnfides, which are found in fome of the mineral 

 veins in Derbyfliirc, fomcthing like the polifhing which is 

 feen often on the iides of faults. Sec Slkkkxsidk. 



Gl.V.s.-; Ijle, called alfo Scalpey, in Geography, one of the 

 Hebrides, near the N.E. extremity of Hams. It is a fmall, 

 low, round ifland, covered with heath, and indented by l lie 

 fea. Near its wettern extremity are two good natural har- 

 hours, and on its eaft point a light-iioufe was erected A. D. 

 1788. It lies at the entrance of Eaft Loch Tarbot. n'. 

 lat. 57 50'. W. long. 6 40'. 



CjLASs-Leatl, in Mining, according to Mr. Mawe, "Mine- 

 ralogy of Derbyfliire," p. loj, is an opaque waxy lead-ore 

 found in that county : fometimes alfo it is tranfparent and 

 cryftallized, appearing as though it had undergone tlie action 

 of lire. 



GL\:-iK-Loug/.; in Gcograpiy, a lake of Ireland, in the 

 county of Moneghcn, near which ii a village of the fame 

 name, about five miles from the town of Moneghen. 

 The lake contains 120 acres ; and a wood, fpieadmg over a 

 fine bold hill, hangs dovrn to the water in one deep lliade, tlnr 

 eff"ea of whicli is remarkably beautiful. The county around 

 is very fine, Young. 



Glasses are diftiuguifhed, with regard to their form, life, 

 &:e. into various kinds, as drinking-glafles, optic-glafles, 

 looking-glaffes, burning-glafTes, &c. 



Glasses, Drinking, are Ample \efll-Is of common glafs or 

 cryftal, ufually made in form of an inverted cone. 



Each glafs confifts of three jiarts, vii. the calyx or bowl ; 

 the bottom, and the foot ; whicli are all wrought or blown 

 feparately. 



Nothing can be more dexterous and expeditious' than the 

 manner wherein thefe parts arc all blown ; two of them 

 opened, and all three joined together. An idea is onlv to 

 be had thereof, by feeing them actually at work. 



The glafics chiefly ufed In England are made of the afhes 

 of fern ; cryftal glaflls being lefs frequent in ufe. The 

 exceeding brittlenefs of this commodity, notwithftanding the 

 eafy rate of each glafs, renders the ccnfumption thereof very 

 connd^rable. For the method of gilding the edges of drink- 

 ing-glafles, fee GlI-DlNt; Crt Enamel and GLifs. 



Gl.vsses, Metallic, in Chemifiry, are the oxyds, or fome- 

 times the fulphuretted oxyds of the different' metals, vitri- 

 fied by heat. 



Glasses, Op.'ic, are thofe made ufe of to llrengthen, im- 

 prove, or preferve the fight. See Optic GlaJJes. 



Gl.\sses, Convex. See Conve.xitv. 



Gl.\sses Concave. See Concave. 



Gl.Vss, Infernal. See Ixr-KHNAL. 



Glasses, Len:icular. See Le.ns. 



Gl.\sses, Menifcus See Meniscus, &c. 



Glasse.s, Plain. See Pl.41\ G/ii/i. 



Gl.\sses, Plano-Coruave. See Pl.vno-Cgs'CAVF. 



Glasses, PLmo-Con-ve.-<. See Plano-Conve.v. 



Gla.sses, Teifcope. Sec Telescope. 



Glass, Ohjecl. See Grject-G/.j//. 



Gl.\sses, Eye. See EvE-(7«7/}. 



Glass, Magnifying. Mee Mai.;xifvin<;. 



Glas--, Muhiplying. See Mlltiplyinu. 



Glasses, Mufical. Sec Ar.monica, • 



GtA«l\ • 



