2967 



ERUPTIVE ROCKS 



and C are measured quantities with 

 possible errors of 1, 2, and 3 

 p.c. respectively, then the result of 

 computations AxBxC, or AxB 

 -^-C, or A-t-B-^C, is subject to an 

 error of (1+2+3), i.e. 6 p.c. 



The practical consequences of 

 these considerations are numerous 

 and important. Unless consider- 

 able time and skill be expended over 

 the operation, measurements ex- 

 pressed by more than three signifi- 

 cant figures are probably incorrect : 

 it is almost certain, for instance, 

 that a value of 16 '34 feet is in- 

 correct ; the final 4 is almost cer- 

 tainly wrong, and the 3 may be 

 doubtful. Consequently it is useless 

 to try to measure 18 '69 yards or 

 26'75 cwts. This fact justifies the 

 grocer who weighs butter, etc., to 

 the nearest half ounce. 



Error, WRIT OF. Name of a writ 

 of appeal to the king's bench in 

 criminal cases, or to the court of 

 exchequer chamber or the House 

 of Lords in civil cases. It was for 

 errors appearing on the record, but 

 it is now abolished in all cases. 



Ersch, JOHANN SAMUEL (1766- 

 1828). German bibliographer. He 

 was born at Grossglogau, Silesia, 

 June 23, 1766, and studied at 

 Halle. He was successively li- 

 brarian, 1800, and professor, 1803, 

 at Jena, and principal librarian, 

 1808, at Halle. His Handbuch der 

 deutschen Literatur seit der Mitte 

 des 18ten Jahrhunderts, 1812-14, 

 laid the foundation of modern 

 German bibliography. In 1818 he 

 began, with J. G. Gruber, the famous 

 Allgemeine Encyklopadie der WIs- 

 senschaften und Kiinste, which was 

 not completed a century later. He 

 died at Halle, Jan. 16, 1828. 



Erse. Early Scottish variant o 

 Irish. In the 14th-15th centuries 

 the term was used of kings and 



PP 



RJI sr cc uu 



Erse. Irish Gaelic alphabet of 

 eighteen letters 



caterans. In the 18th century it 

 denoted Gaelic speech ; at first 

 Scottish Gaelic, and subsequently 

 Irish Gaelic. It is no longer in cur- 

 rent usage in this sense. In modern 

 philology it sometimes designates 

 the language - group, embracing 

 Gaelic and Manx, which is now 

 usually called Goidelic. See Gaelic 

 Language and Literature ; Goidels; 

 1 reland : Language and Literature. 

 Ersekujyar. Town of Czecho- 

 slovakia, formerly in Hungary, 

 now known as Nove Zamky. It oc- 



cupies an important situation on ' 

 the Nyitra (Nitra) river, and is both 

 a rly. and road junction, 57 m. by 

 rly. almost due E. of Bratislava 

 (Pressburg). Pop. 16,2CO, nine- 

 tenths Roman Catholic Magyars. 



Erskine, EBENEZER (1680-1754) 

 Scottish divine and founder of the 

 Secession Church. Born at Dry- 

 burgh, in 

 Berwickshire, 

 June 22, 1680, 

 the son of a 

 minister, he 

 was educated 

 at Edinburgh 

 Uni versitv. 

 His first 

 charge was 

 at Portmoak, 

 i n Kinross - 

 moved to a 

 There he came 



Ebenezer Erskine, 

 Scottish divine 



shire, whence he 

 church at Stirling, 

 into collision with his ecclesiastical 

 superiors, and the matter came 

 to a head when, in 1732, he de- 

 clared that parishes should choose 

 their own ministers. This led to his 

 suspension, but with some associ- 

 ates he founded a separate presby- 

 tery, which developed into the 

 Secession Church. In this Erskine 

 remained until 1748, when the 

 section opposed to him secured his 

 removal from the ministry. He 

 died at Stirling, June 2, 1754. See 

 Presbyterianism; Secession Church ; 

 consult also The Erskines, A. R. 

 MacEwen, 1900. 



Erskine, JOHN, OF DUN (1509- 

 91). Scottish reformer. He was edu- 

 cated at King's College, Aberdeen, 

 travelled on the Continent, and 

 in 1534 returned with a French 

 scholar, who introduced the study 

 of Greek into Scotland. His en- 

 thusiasm was equally divided be- 

 tween the new learning and the new 

 faith. He was an ultimate friend of 

 John Knox, and his influence was 

 always exerted in the direction of 

 moderation. He was several times 

 moderator of the general assembly 

 and vi 1579 was appointed a 

 member of the king's council. 



Erskine, THOMAS ERSKINE, IST 

 BARON (1750-1823). British lawyer. 

 A younger son of the 10th earl oi 

 Buchan, he 

 was born in 

 Edinburgh, 

 Jan. 10, 1750. 

 After a scanty 

 education a t 

 Edinburgh 

 and St. An- 

 drews, he en- 

 tered the navy 

 1st Baron Erskine, in 1764, but 

 British lawyer soon trans . 



AflerHoppner ferred fa the 



army. This career, too, he aban- 

 doned after a few years, and in 

 1778 he was called to the bar. 



As a barrister Erskine's success 

 'was instantaneous. He made his 

 name in his first case, and in 1781 

 he added to his reputation when 

 junior counsel for Lord George 

 Gordon. In 17 83 he was elected M. P. 

 for Portsmouth, and after six years' 

 absence he was again returned for 

 that borough in 1790. He made no 

 mark in Parliament, but, having 

 been attorney -general and chan- 

 cellor to the prince of Wales, he was 

 lord chancellor in the Whig ministry 

 of 1806-7. He was then raised to 

 the peerage. He died Nov. 1 7, 1823. 

 The barony still remains with his 

 descendants. See Speeches, ed. 

 J. Ridgway, with Memoir by Ld. 

 Brougham, 4 vols., 1847 ; Lives of 

 the Chancellors, Lord Campbell, 

 4th ed. 1856-57. 



Erskine's eldest brother, Henry 

 Erskine (1746-1817), was also a 

 distinguished advocate. Trained at 

 St. Andrews and Edinburgh for 

 the Scottish bar, he was lord advo- 

 cate in 1783, and again in 1806-7. 

 He was for a short time M.P. and 

 died Oct. 8, 1817. Like his brother, 

 his reputation rests upon his stately 

 and pleasing eloquence. See Life, 

 A. Fergusson, 1882. 



Erskine ville. Industrial suburb 

 of Sydney, New South Wales. 

 Pop. 7,299. See Sydney. 



Erubescite (Lat. erubescere, to 

 grow red). Ore of copper also 

 known as variegated copper pyrites 

 and as horse-flesh ore. In colour it 

 varies between copper-red and 

 pinkish brown ; it is brittle and 

 tarnishes rapidly on exposure ; its 

 specific gravity is 5. Chemically it 

 is a sulphide of the metal, its com- 

 position being copper 62 '8, sulphur 

 25 '7, and iron 11, and traces of 

 impurities. It does not occur 

 in large quantities, but is found 

 frequently with other copper pyri- 

 tous ores in granite and allied for- 

 mations in Cornwall, Ireland, Nor- 

 way, Silesia, Saxony, Siberia, the 

 U.S.A., and Canada. See Copper. 



Eruptive Rocks. Rocks which 

 have been either extruded at the 

 surface of the earth or have con- 

 solidated beneath the surface under 

 pressure of overlying rock-masses. 

 Those extruded (effusive rocks), as 

 in volcanic eruptions, are of the 

 type of lava and are found near vol- 

 canoes, active or extinct ; they fre- 

 quently exhibit flow-structure, in- 

 dicating rapid consolidation. Ba- 

 salts and rhyolites are examples. 



Rocks consolidated beneath the 

 surface (intrusive rocks) are of two 

 kinds : very deep-seated (plutonic) 

 and less deep-seated (hypabyssal). 

 Plutonic rocks are usually coarsely 

 crystalline, never glassy or with 

 vapour cavities ; hypabyssal rocks 

 are often coarsely crystalline, but 

 show great variation in structure. 



