SIEGE ARTILLERY 422 SIENA tions. The batteries necessary are "en- filade" batteries, placed on the prolonga- tions of all the important works attacked ; "counter" batteries, to overcome the fire of the works bearing upon the field of attack; "mortar" and "howitzer" bat- teries, to search by high angle fire the interior of all the works attacked; and "breaching" batteries, to breach by curved fire the scarps and flanking casements. Light pieces, such as the seven-pounder mountain guns and machine guns, are placed in the second and third parallels, and in the "demi-parallels" or lodgments, 100 to 150 yards long, made on each ap- proach about half way between these parallels. Beyond the third parallel the besieger will probably be met by counter mines, and himself have to resort to mining in order to carry out the crowning of the covered way. The World War developed a more or less new system of siege. See World War: Artillery. Siege in History. — Among great sieges in the world's history may be mentioned those of Troy, Tyre (572, 332 b. a), Syr- acuse (396 B. C.J, Saguntum (219 B. a), Jerusalem (a. d. 70), Acre (1192, etc.), Calais (1347), Orleans (1428), Constan- tinople (1453), Haarlem (1572-1573), Leyden (1574), Breda (1625), Rochelle (1628), Magdeburg (1631), Breisach (1638), Taunton (1644-1645), London- derry (1689), Gibraltar (1731, 1779, 1782- 1783), Prague (1741-1744), Leipsic (1757, 1813), Quebec (1759-1760), Seringapatam (1799), Genoa (1800), Saragossa (1808- 1809), Ciudad Rodrigo (1810, 1812), New Orleans (1814), Antwerp (1832), Rome (1849), Sebastopol (1854-1855), Kars (1855), Lucknow (1857), Delhi (1857), Gaeta (1860-1861), Vicksburg (1863), Charleston (1864-1865), Richmond (1864- 1865), Metz (1870). Strasburg (1870), Belfort (1870-1871), Paris (1870-1871), Plevna (1877), Khartum (1884), Lady- smith (1900), Port Arthur (1904), Adri- anople (1912); Liege (1914), Przemysl (1914-1915); Verdun (1915-1916). SIEGE ARTILLERY. See ARTILLERY. SIEGEN, a town of Prussia, in West- phalia, on the Sieg river; 47 miles E. of Cologne; manufactures leather, paper, linen, soap, iron, copper, lead, zinc, etc., having many mines in the vicinity. Siegen was the birthplace of Rubens. Pop. about 27,300. SIEMENS, WERNER VON, a Ger- man engineer and electrician; born in Lenthe, Hanover, Dec. 13, 1816. 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 connec- tion the valuable insulating property of gutta-percha for underground and sub- marine 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 estab- lished in 1847 in Berlin; and subsequently branches were formed, chiefly under the management of the younger brothers of Werner Siemens, in St. Petersburg (1857), in London (1858), in Vienna (1858), and in Tiflis (1863). Besides de- vising numerous useful forms of galva- nometers and other electrical instruments of precision, Werner Siemens was one of the discoverers of the principle of the self-acting dynamo. He also made val- uable determinations of the electrical resistance of different substances, the resistance of a column of mercury one meter long and one square millimeter cross section at 0° C. being known as the Siemens unit. His numerous scientific and technical papers, published in the "Proceedings" of the Berlin Academy (of which he became a member in 1874), in Poggendorff's "Annalen," in Dingler's "Polytechnische Journal," etc., were re- published 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 in Berlin, Dec. 6, 1892. SIENA, or SIENNA, a city of central Italy, on three connecting hills on the S. frontiers of Tuscany, 59 miles S. of Flor- ence, is surrounded by old walls, entered by nine gates, and has also a citadel; the streets are irregular, steep and narrow. It has a university with faculties of law and medicine, and a cathedral, begun in the early years of the 13th century, which is one of the finest examples of Italian Gothic architecture. The municipal pal- ace, begun in 1288, is a fine specimen of Pointed Gothic. It stands in the historic Piazza del Campo, now the Piazza di Vit- torio Emmanuele, a large open semicir- cular space in the center of the city, and is adorned with frescoes of the Sienese school. The institute of fine arts contains a valuable collection of pictures of the oldest Sienese painters. There are vari- ous other buildings of interest, including churches and palaces. The manufactures are not of much importance. In the Mid- dle Ages Siena gave its name to a school
