370 



GRAYSTONE 



GREAT BRITAIN 



represented by five species, inhabiting clear streams 

 in north Europe, Asia, and North America. The 

 British Grayling (Th. vulgaris) has a wide but 

 local distribution ; it prefers rivers with rocky or 



Grayling (Thymallus vulgaris). 



gravelly bottom and an alternation of stream and 

 pool. The back and sides are silvery gray, with 

 longitudinal dusky streaks ; the dorsal fin is crossed 

 by rows of spots. The fish, which may attain a 

 weight of 4 to 5 lb., is esteemed for the table, but 

 should be cooked when newly caught, when it has 

 an odour compared to that of wild thyme. It 

 spawns in April or May, and is in best condition 

 when trout are out of season, in October and 

 November. Another well-known species is Th. 

 signifer, a beautiful fish from the clear affluents 

 of the Mackenzie River, called ' Hewlukpowak,' or 

 'fish with the winglike fin, '.by the Eskimos, and 

 ' poisson bleu ' by the Canadian voyageurs. See 

 Pritt, The Book of the Grayling (1888); Walhain, 

 Grayling, and how to catch them ( 1895). 



Graystone, Graywacke, &c. See GREY- 

 STONE, GREYWACKE, &c. 



Graz. See GRATZ. 



Grazalema, a town of Spain, situated in a 

 very strong natural position 53 miles ENE. of Cadiz. 

 Its 8000 inhabitants are principally engaged in 

 manufacturing cloth and in smuggling. 



Grease, a term of general application to all 

 oily or fatty matters, but generally to those having 

 some degree of solidity, as tallow. It is more 

 specially applied to fatty matters which are so 

 deteriorated by dirt or other impurities as to be 

 unfit for candle-making and other manufactures 

 requiring some degree of purity in the material. 

 Grease is largely employed as a lubricant for 

 heavy machinery, and especially for the wheels of 

 carriages. The grease employed for the axles of 

 wagons and carts consists of inferior kinds of 

 grease mixed with a little tar. On English rail- 

 ways grease is used for goods and mineral wagons ; 

 for passenger carriages palm-oil is used. See LUB- 

 RICANTS. 



Great Basin, a remarkable triangular plateau 

 of North America, occupying the western portion 

 of Utah and nearly the whole of Nevada, as well 

 as a section of Oregon and California, and extend- 

 ing at its north-eastern angle into Idaho. It is 

 bounded on the W. by the Sierra Nevada, and on 

 the E. by the Wahsatch Mountains. The base of 

 the triangle, in the N., is some 500 miles from east 

 to west ; it extends from N. to S. for nearly 800 

 miles, and its area is slightly greater than that of 

 France. It is girdled round on every side by high 

 mountains, and traversed throughout by numerous 

 ranges, frequently parallel, yet as often irregularly 

 blending or crossing ; the valleys are usually sinks, 

 the chief drainage centre being Great Salt Lake 

 (q.v.), and the Humboldt and Carson sinks, at about 

 the same elevation. It has been pointed out by 

 the United States Geological Survey that the Great 

 Basin's areas of greatest depression are to be found 

 near the borders, while its central portion reaches 



a much greater elevation. The loftiest range is the 

 East Humboldt, near the middle, which culminates 

 in Mount Bonpland ( 11,321 feet). Volcanic masses 

 form or conceal the original rocks of many of these 

 ranges. The Great Basin contains many streams 

 and lakes, the latter for the most part salt, whose 

 waters never reach the ocean, but are either taken 

 up by evaporation or sink in the desert sands. The 

 mean annual rainfall ranges in different localities 

 from 4 to 15 inches. The plateau is nearly desti- 

 tute of trees, and in general only the upper parts 

 of the valleys are clothed with desert shrubs, 

 their lower portions often being occupied either 

 by bodies of water or by a muddy bottom covered 

 with several inches' depth of alkaline salts left by 

 evaporation. 



See, besides reports to the United States Geol. Survey, 

 works by I. C. Russell <>n Lake Lahontan (1883 and 1885) 

 and Southern Oregon (1884); and Hague, The Volcanic 

 Rocks of the Great Basin (1884). 



Great Bear Lake. See BEARLAKE ( GREAT ). 



Great Britain. Under this head are noticed 

 ( 1 ) the island of Great Britain its geology and 

 geography ; and (2) the United Kingdom of Great 

 Britain and Ireland its general statistics, &c. 



Great Britain was so called to distinguish it 

 from Britannia Minor, or Brittany, in France (see 

 BRITANNIA ). The name was a poetical or rhetorical 

 expression till in 1604 James I. styled himself king 

 of Great Britain, although the term was proposed 

 in 1559 by the Scottish Lords of the Congregation. 

 Lying between 49 57' 30" and 58 40' 24" N. lat. , and 

 between 1 46' E. and 6 13' W. long., Great Britain 

 is the largest island of Europe. It is bounded 

 on the N. by the Atlantic, on the E. by the North 

 Sea, on the S. by the English Channel, and on the W. 

 by the Atlantic, the Irish Sea, and St George's Chan- 

 nel. The most northerly point is Dunnet Head, in 

 Caithness ; the most southerly, Lizard Point, in 

 Cornwall ; the most easterly, Lowestoft Ness, in 

 Suffolk ; and the most westerly, Ardnamurchan 

 Point, in Argyllshire. Its greatest length is about 

 608 miles, and its greatest breadth (from Land's 

 End to the east coast of Kent) about 325 miles; 

 while its surface contains 88,226 sq. m. 



Geology. The geology of Great Britain is of pecu- 

 liar importance. The fossiliferous strata having 

 been first systematically studied and expounded 

 here, British geologists have given to the world 

 the names whereby most of the larger divisions 

 and subdivisions of these strata are known. Nearly 

 all the recognised ' systems ' occur in Britain, 

 although some of these are more fully represented 

 elsewhere. Indeed, the only system not found 

 in Britain is the Miocene the beds formerly 

 classed as of this age being now included in 

 the Oligocene. British geology is no less import- 

 ant from the influence it has had in the develop- 

 ment of the country. The mineral wealth, especi- 

 ally the coal and the iron, are the real sinews 

 and muscles of Britain's mighty power. No other 

 country has similar advantages in such an area. 

 ( See also the article on the geology of EUROPE. ) 



We shall, in this sketch of the distribution of the 

 British rocks, follow the order of the strata, begin- 

 ning with the lowest and oldest. It may be said 

 that, in general, the mountainous regions of the 

 north and west are formed of the oldest rocks, and 

 that, as we move south-eastwards, we gradually 

 pass over newer strata, until, in the east of Eng- 

 land, we come to the uppermost divisions of the 

 Tertiary. 



The base rocks of the whole series occur in the 

 Outer Hebrides, in Rona, Tiree, and Coll, and along 

 the western shores of Sutherland and Ross. They 

 are assigned to the Archrean System (q.v.), and 

 consist chiefly of coarse gneiss, usually hornblendic. 



