ORE S 



GRAV'ITY. A term used in physics to de- 

 note the cause by which all bodies move 

 towards each other, unless prevented by 

 some other force ; and which operates di- 

 rectly as the mass, and inversely as the 

 square of the distance. Weight is the 

 measure of gravity. Specific gravity of a 

 body is the ratio of its weight to that of 

 an equal volume of water assumed as a 

 standard. 



GRAZIOSO (It.), in music, signifies ele- 

 gantly and gracefully. 



GREASE. In farriery, an inflammation 

 and swelling of the heels of a horse, with 

 secretion of an oily matter. 



GREAVE, Fr. grii-e. A piece of armour 

 defending the shins. 



GREAVES, \ The sediment of melted 



GRAVES. / tallow. 



GREEK FIRE, a formidable combustible 

 composition, employed by the Constant! - 

 nopplitan Greeks of the middle ages 

 against the Mahometans. Its composition 

 was kept a secret, and is not now cer- 

 tainly knoM-n, but it is supposed to have 

 been a compound of asphaltuni, sulphur, 

 and nitre. 



GREEK CH CRCH. It comprises the great 

 bulk of the Christian population of Russia, 

 Greece, Moldavia, and Wallachia, all ac- 

 knowledging the patriarch of Constanti- 

 nople as their head. 



GREEK ORDERS. In architecture, these 

 are the Doric, Ionic, and Corinthian, in 

 contradistinction to the two Latin orders, 

 the Tuscan and Composite. 



GREEN-CLOTH, a court of justice, held in 

 the counting-house of the Queen's house- 

 hold, composed of the lord steward and the 

 officers under him. It has jurisdiction of 

 the court-royal, which extends every 

 v ay 200 yards from the gate of the palace. 

 It takes its name from the green cloth 

 spread over the board at which it is held. 



GREEN-EARTH, a variety of talc of a 

 pleasant green colour, which occurs in 

 vesicular cavities in amygdaloid, in Eng- 

 land and Scotland. It is the mountain 

 green of artists in water colours, and when 

 ground with oil, is employed as a paint. 



GREEN PAINTS or PIGMENTS. These are 

 prepared by admixture of blues and yel- 

 lows. Eninstcick green is a mixture of 

 carbonate of copper with chalk, lime, &c. 

 frisegreen is an ammono^sulphate of cop- 

 per. Mittis green is an arseniate of copper. 

 Mountain green is a hydrated carbonate 

 of copper. Sap green is the inspissated 

 uice of buckthorn berries. Scheele's green 

 is arsenite of copper. Verona green is a 

 variety of green earth. 



GREEN ROOM. In theatres, the actors' 

 retiring room, so called from being painted 

 or decorated in green. 



GREEK VITRIOL, crystallised sulphate of 

 iron ; the crystals of which are green. 



GBECJO'KIAN TELESCOPE, the first and 



GRO 



most common form of reflecting telescope, 

 invented by Professor James Gregory. 



GREGO'RIAN YEAR, the Julian year cor 

 rccted by the abatement of three bissex- 

 tiles every 400 years, as allowance for the 

 11 minutes which the Julian year exceeds 

 the solar year. This reformation was ef- 

 fected by Pope Gregory XIII., A.D. 1582, 

 when 10 days were taken out of October 

 to make the equinox fall on the 21st of 

 March, as it did at the time of the ge- 

 neral Council of Nice, A.D. 325. The Gre- 

 gorian year still requires correction to the 

 extent of 80 minutes every 400 years. 



GRENA'DE. In tear, a small bomb or 

 shell of metal about 2j inches diameter, 

 filled with fine powder, and furnished 

 with a fusee, which being lighted, the 

 shell is thrown by the hand among the 

 enemy : hence called most commonly Juinil- 

 grena'de, hence grenadier. 



GRET'WEATHERS. In geology, large 

 boulders of siliceous sandstone, found in 

 various localities. 



GRIF'FIN, I Lat. gryps, gnjphus. An 



GRIF'FON, ) imaginary animal, said to 

 have been generated between an eagle 

 and a lion. It is represented on ancient 

 medals with four legs, wings, and a beak, 

 and is still borne in coat-armour. 



GRIL'LAOE , a term applied to the sleepers 

 and cross-beams supporting a platform, 

 upon which some erections are carried 

 up, as piers, in marshy soils, whereby an 

 equal bearing is given to the foundation. 



GRIPE. In nautical language, 1. The 

 piece of timber called otherwise the fore- 

 foot, faced against the lower piece of the 

 stern from the foremost end of the keel, 

 and joining with the knee of the head : 

 used to defend the lower part from in- 

 jury. 2. The compass of a ship's stern 



under water. 3. To gripe is to run to 



windward. 4. Gripes are an assemblage 



of dead-eyes, ropes, and hooks, fastened to 

 ringbolts in the deck to secure the boats. 



GRIT or GRITSTONE, a coarse siliceous 

 sandstone, sometimes called mill-stone 

 grit, from the circumstance of some quar- 

 ries of it being worked for mill-stones. 

 It affords also good building stones. 



GROAT, a silver coin struck in the reign 

 of Edward III., and so named from its 

 being four times greater than the silver 

 penny, the only silver coin previously m 

 use. The term means money in amount 

 equal to 4d. 



GROATS, decorticated oats. 



GROG, some spirituous liquor, as rum or 

 whisky, diluted with water. 



GROIN. 1. In architecture (see GROTNED 



ARCH). 2. In engineering, a framework. 



usually of wood, constructed acro a 

 beach between high and low water-mark, 

 for the purpose of retaining the shinsrle 

 already accumulated, or to obtain more 

 from the sea. 



