SIENITE SIERRA LEONE. 



251 



Each labourer places his fascine before him, throws 

 the ground over it, and thus a kind of breastwork 

 is formed, constituting the first parallel, where the 

 forces directed against the fortress may be collected. 

 The besieged, by sallies and counter operations of 

 every kind, strive to drive off the labourers and to 

 destroy their work, while, on the other hand, the 

 besiegers make efforts to establish themselves more 

 and more securely, to raise batteries, and then, by 

 means of trendies, dug for this purpose, and new 

 parallels, which more and more closely encircle the 

 fortress, to approach the moat, while the artillery 

 is kept constantly playing from the batteries on the 

 garrison as well as the works and guns of the be- 

 sieged. With this the bombardment from the 

 mortar-batteries is usually combined (see Battery), 

 for the purpose of dislodging the garrison from 

 their works, of dismantling the works themselves, 

 and of destroying buildings, magazines, &c. From 

 the last parallel, which approaches very near the 

 moat of the fortress, the besiegers prepare to cross 

 the moat, and endeavour to make breaches. Here 

 likewise mining operations (see Mine) are carried 

 on, whenever they are found advisable. The moat 

 is crossed in saps, or covered passages of a similar 

 kind, and, should it be filled with water, on rafts, 

 bridges, &c. When at last the breaches are practi- 

 cable, the works of the strong-hold as much as pos- 

 sible demolished, the garrison and their artillery 

 impaired, then follows the storming or scaling of 



the walls To raise the siege of a fortress, is to 



compel the enemy to retire from the place. They 

 may be forced to this by inundations, if the situa- 

 tion of the place admits of them ; by want of pro- 

 visions, if the surrounding country has been deso- 

 lated, or the convoys intended for them be captured; 

 or, finally, by assault. If it is impossible to drive 

 away the enemy, a temporary interruption of the 

 siege is attempted, in order to introduce provisions 

 or fresh troops into the fortress. This is generally 

 done by a sudden attack on the lines of the besiegers, 

 and forcing a way through them, with the co-opera^ 

 tion of the besieged. 



SIENITE; one of the primitive rocks, differing 

 from granite chiefly in the substitution of hornblende 

 for mica; but feldspar forms its most abundant in- 

 gredient, and is often red. When the quartz and 

 hornblende are fine-grained, and the feldspar in dis- 

 tinctly imbedded crystals of considerable dimensions, 

 the rock is called porphyritic sienite, or sienite-por- 

 phyry. Sienite is sometimes unstratified, though 

 more commonly manifesting a tendency to the co-> 

 lumnar structure. It embraces no foreign beds. 

 It occurs in uncohformable and overlying stratifica- 

 tion, over granite, gneiss, mica- slate and clay-slate. 

 It is equally prolific in metals as porphyry. In the 

 island of Cyprus, it affords much copper. Many of 

 the important silver and gold mines in Hungary are 

 situated in sienite. In the forest of Thuringia, it' 

 affords iron. It abounds in Upper Egypt, at the 

 city of Syene, in the Thebaid, at the cataracts of 

 the Nile, whence it derives its name. The Romans 

 Drought it thence to Rome, for architectural pur- 

 poses and for statuary. 



SIENNA, OB SIENA; an ancient city of Tus- 

 cany, the capital of the province of Sienna. Being 

 built on three eminences, the streets are extremely 

 uneven, winding, and narrow, so that the chief part 

 of the town is impassable for carriages. The only 

 handsome public square is that in which is the 

 town-house, and which contains a beautiful foun- 

 tain. The. esplanade is a fine shady avenue leading 



to the citadel, the ramparts of which, planted with 

 trees, and laid out in the form of terraces, afford 

 several interesting points of view. The cathedral 

 of Sienna is a magnificent marble structure in the 

 Gothic style, built in the thirteenth century, by 

 Giovanni Pisani, and accounted inferior to none in 

 Italy, except St Peter's at Rome. The town-house 

 is a large building, also in the Gothic style, and 

 surrounded with porticoes. Adjoining is the 

 theatre, rebuilt since 1750. There are in Sienna 

 several family mansions, or palaces, but none of 

 remarkable architecture. The manufactures of 

 Sienna comprise woollen, leather, paper, and hats, 

 but all on a small scale. This town is the seat of 

 a university. Sienna lays claim to great antiquity, 

 but it was long a petty place. Its prosperity was 

 greatest during the middle ages, when it enjoyed 

 an extensive commerce, and is said to have had a 

 population of 150,000. It long maintained itself 

 as an independent republic ; but, intestine divisions 

 favouring the designs of foreign powers, it became 

 successively subject to French and Spanish invaders. 

 Population, 24,000; Ion. 11 10' 15" E.; lat. 43 

 22' N. 



SIERRA (Spanish}, SERRA (Portuguese*); a 

 chain of mountains. 



SIERRA LEONE; a country of Western 

 Africa, on the Atlantic, distinguished for the 

 colony formed there by the British nation, rather 

 from motives of philanthropy than from those of 

 commercial advantage. It is traversed by a con- 

 siderable river, called the Mitomba or Sierra Leone. 

 The name is derived from a ridge of mountains, 

 which rises near the southern bank of the river. 

 This country equals, in fertility and populousness, 

 any other in this part of Africa. It consists 

 generally of one vast, almost impenetrable forest, 

 only particular spots of which have been cleared 

 and cultivated. Rice is raised wherever the ground 

 is sufficiently watered for its production, and forms 

 the constant food of the rich ; but the poor content 

 themselves with millet, yams, and plantains. There 

 is great abundance of the most delicate fruits. 

 Elephants' teeth and civet are brought to the 

 coast. The woods and mountains are infested 

 with wild animals, particularly lions, from the mul- 

 titude of which the country appears to have derived 

 its name. There are swarms of insects, flies, mos- 

 quitoes, and particularly ants, the white species of 

 which commit extraordinary devastation. The 

 serpent species are also very numerous. The 

 rivers, besides yielding an ample supply of fish for 

 food, contain large alligator^, and the manata or 

 sea-cow. The natives of this country are not of 

 so deep black a complexion as those of cape Verd, 

 nor have they the flat nose of the negro race to 

 such a degree. The character of the different 

 tribes varies greatly. 



The Portuguese were the first who discovered 

 and formed settlements on the river Sierra Leone. 

 Towards the close of the eighteenth century, the 

 British began to turn their views towards Sierra 

 Leone, with a view to colonization, for the more 

 effectual abolition of the slave-trade, by raising up 

 an African colony, whither the slaves might be 

 sent as freemen. Lord Mansfield having decided, 

 in 1772. that a slave who sets foot in Britain 

 becomes free, a number of blacks in England left 

 their masters, and were wandering about in a 

 desolate condition. Granville Sharp formed the 

 plan of transporting them to Africa; and, the aid 

 of the government having been obtained, they 



