S1EGEN 



SIENNA 



439 



the positions thus gained a further advance, ii 

 necessary, can be made until the last retrenchment 

 is taken, and the place falls. See also FoRTIFlCA 

 TIOS, and MINES. 



Among great sieges in the world's history may 

 be mentioned those of Troy, Tyre (572, 332 B.C.), 

 Syracuse (396 B.C.), Saguntum (219 B.C.), Jerusalem 

 (70 A.D.), Acre (1191, &c.), Calais (1347), Orleans 

 (1428), Constantinople (1453), Haarlem (1572-73), 

 Leyden (1574), Breda (1625), Kochelle (1628), 

 Magdeburg (1631), Breisach (1638), Taunton 

 (1644-45), Londonderry (1689), Gibraltar (1731, 

 1779, 1782-83), Prague (1741-14), Leipzig (1757, 

 1813), Quebec (1759-60), Seringapatam (1799), 

 Genoa (1800), Saragossa (1808-9), Cwdad Rodrigo 

 (1810, 1812), New Orleans (1814), Antwerp (1832), 

 Rome (1849), Sebastopol (1854-55), Kars (1855), 

 Lucknow (1857), Delhi (1857), Gaeta (1860-61), 

 Vicksburg (1863), Charleston (1863-64), Richmond 

 (1864-35), Metz (1870), Strasburg (1870), Belfort 

 (1870-71), Paris (1870-71), Plevna (1877), and 

 Khartoum (1884). 



The state of siege as defined by continental 

 jurists is a condition of things in which civil law 

 is suspended or made subordinate to military law. 

 A fortress, city, or district is thus put under 

 martial law i.e. under the authority of tin- 

 military power either on account of the presence 

 of an enemy, as at a siege, or because of the failure 

 of the civil power, as in the case of domestic in- 

 surrection, or of a conquered district in military 

 occupation. The minor state of siege, a modifica- 

 tion of the more severe rule, usually suffices for 

 domestic troubles. No such provision is made by 

 the laws of the British Empire or of the United 

 States, though very similar powers are exercised 

 when martial law is proclaimed. For this no rules 

 are made the possibility of civil war is not pre- 

 supposed ; but should the civil power become in- 

 operative it is the duty of the supreme authority 

 to maintain order by any means (usually of course 

 an armed force) that are available, afterwards 

 coming to parliament for an act of indemnity to 

 justify conduct in itself contrary to law. Perhaps 

 an approach to the continental minor slate of siege 

 may be found in the restricted power to try 

 offenders in Ireland by military tribunals created 

 by act of parliament in 1799, 1803, and 1833. 



Steven, a town of Prussia, in Westphalia, 

 stands on the Sieg, 47 miles E. of Cologne, manu- 

 factures leather, paper, linen, soap, iron, copper, 

 lead, zinc, &c., having many mines in the vicinity. 

 Siegen was the birthplace of Rubens. Pop. 16,676. 



Siegfried, or SIGFRID. See NIBELUNGEXLIED. 



Siemens, WERNER voN.engineerand electrician, 

 was born December 13, 1816, at Lenthe in Hanover. 

 In 1834 he entered the Prussian Artillery, and in 

 1844 was put in charge of the artillery workshops 

 at Berlin. He early showed scientific tastes, and 

 in 1841 took out his first patent for galvanic silver 

 and gold plating. He was of peculiar service in 

 developing the telegraphic system in Prussia, and 

 discovered in this connection the valuable insulat- 

 ing property of gntta-percha for underground and 

 submarine cables. In 1849 he left the army, and 

 shortly after the service of the state altogether, 

 and devoted his energies to the construction of 

 telegraphic and electrical apparatus of all kinds. 

 The well-known firm of Siemens and Halske was 

 established in 1847 in Berlin ; and subsequently 

 branches were formed, chiefly under the manage- 

 ment of the younger brothers of Werner Siemens, in 

 Ht Petersburg (1857), in London (1858), in Vienna 

 ( 1 858 ), and in Tiflis ( 1 863 ). Besides devising numer- 

 ous useful forni.H of galvanometers and other electri- 

 cal instrument* of precision, Werner Siemens was 

 one of the discoverers of the principle of the self- 



acting dynamo ( see DYNAMO ). He also made valu- 

 able determinations of the electrical resistance of 

 different substances, the resistance of a column of 

 mercury, one metre long and one square milli- 

 metre cross section at 0C., being known as the 

 Siemens Unit. His numerous scientific and tech- 

 nical papers, written for the various journals, were 

 republished in collected form in 1881. In 1886 he 

 gave 500,000 marks for the founding of an imperial 

 institute of technology and physics ; and in 1888 he 

 was ennobled. He died at Berlin, 6th December 

 1892. See his Personal Recollections (translated, 

 1893) and his Scientific Papers (2 vols. 1892-95). 



Siemens SIR WILLIAM (KARL WILHELM), 

 the youngest brother of Werner Siemens, was 

 liorn at Lenthe in Hanover, April 4, 1823. He 

 was educated at the trade school at Magdeburg, 

 and spent a year in study at Gottingen University, 

 where he worked hard at science. In 1843 he 

 visited England, and was successful in introducing 

 a process for electro-gilding invented by his brother 

 VI erner and himself. In 1844 he again came to 

 England and patented his differential governor. 

 Thenceforward he made England his home, and 

 became a naturalised British subject in 1859. In 

 1862 he was elected a Fellow of the Royal Society, 

 and was presented with the Royal Albert Modal 

 (1874) and with the Bessemer' Medal (1875) in 

 recognition of his researches and inventions in 

 heat and metallurgy. He filled the president's 

 chair in the three principal engineering and tele- 

 graphic societies of Great Britain, ami in 1882 was 

 president of the British Association. He was 

 knighted in April 1883, and died mi November 19 

 of the same year. As manager in England of the 

 firm of Siemens Brothers, Sir William Siemens was 

 actively engaged in the construction of overland and 

 submarine telegraphs. The steamship Faraday 

 was specially designed by him for cable-laying. 

 In addition to his laliours in connection with elec- 

 tric lighting, Sir William Siemens also successfully 

 applied, in the construction of the Portrush Electric 

 Tramway (opened 1883), electricity to the produc- 

 tion of locomotion. In his regenerative furnace 

 ( 1856; see Vol. V. p. 240) he utilised in an ingenious 

 way the heat, which would otherwise have escaped 

 with the products of combustion. The process was 

 subsequently applied in many industrial processes, 

 but notably by Siemens himself in the manufac- 

 ture of steel (see IRON). Of his miscellaneous 

 inventions and researches, the following are par- 

 ticularly worthy of mention : A water-meter ; a 

 thermometer or pyrometer, which measures by the 

 change produced in the electric conductivity of 

 metals ; the bathometer, for measuring ocean 

 depths by variations in the attraction exerted on 

 a delicately suspended body ; and the hastening of 

 vegetable growth by use of the electric light. 



See his Life (1889) by Pole and his Scientific Works 

 (1889). 



Sienkiewicz, HENRIK, Polish novelist (see 

 POLAND, p. 275) born in 1846, has visited Cali- 

 fornia ana Africa. A number of his works ( The. 

 Deluge, Children of the Soil, Yanko the Musician, 

 With Fire and Sword, Quo Vadis f &c. ) have been 

 translated most of them by Jeremiah Curtin. 



Sienna ( Ital. Siena ), a Tuscan city 60 miles by 

 rail S. of Florence, with many mediaeval features, 

 siirh as its walls and citadel. The chief architec- 

 ;ural glory of Sienna is her cathedral, one of the 

 inest examples of Gothic work in Italy. It was 

 >egun early in the 13th century ; in 1339 it was 

 ntended to build a vastly larger church, of which 

 ihe existing cathedral should have been only one 

 transept. But after the plague of 1348 the idea 

 was abandoned, and only ruined walls indicate the 

 ambitious design. The magnificent west front of 



