Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/852

Rh 820 basin. The western possesses a comparatively smooth and unindented coast-line. It is bounded on the south by the coast of Africa and the north coast of Sicily, and it is further enclosed by the coasts of Spain, France, and Italy, which form a roughly arc-shaped coast-line. There are comparatively few small islands in this basin, though some of the more important large ones occur in it. The eastern basin is by far the larger of the two, and extends from Cape Bon to the Syrian coast, including as important branches the Adriatic and the yEgean. The latter is con nected directly, through the &quot;Hellespont, the Sea of Marmora, and the Bosphorus, with the Black Sea. The entrance to the western basin and to the sea generally from the ocean is through the Straits of Gibraltar in 3G N. lat. If this parallel be drawn out through the sea it will be found that the western basin lies almost wholly to the northward, and the main body of the eastern one to the southward of it, the mean latitude of the western basin being about 39 30, and that of the eastern basin 35. They communicate with each other by the channels separ ating Sicily from Italy and from Africa. The former is known as the Strait of Messina, and is of insignificant size, the latter is a wide channel apparently without any distinc tive name, and generally shallow. The greatest depth on the shallowest ridge reaching from the African to the Sicilian coast is under 200 fathoms, and agrees very closely with the corresponding depth at the entrance to the Straits of Gibraltar. Depth. So far as is at present known, the maximum depth is pretty nearly alike in the two basins, being 2040 fathoms in the western and 2150 fathoms in the eastern. Many lines of soundings have been run in the Mediterranean for telegraph purposes, and they afford a very good idea of the general configuration of the bottom. Between Marseilles and Algiers the depth ranges generally from 1200 to 1600 fathoms; between Naples and Sardinia from 1500 to 2000; between Alexandria and Rhodes from 1200 to 1GOO; and between Alexandria and Cyprus from 900 to 1100. The basin of the Mediterranean really begins about 50 miles to the westward of Gibraltar. It is here that the shallowest ridge stretches across from Africa to Spain ; the maximum depth on it is probably not more than 180, and certainly less than 200 fathoms. From this ridge the bottom slopes quickly westward into the depths of the Atlantic, and gently eastward into the Mediterranean. The depth nowhere reaches 1000 fathoms until beyond Alboran Island, 120 miles east of Gibraltar. This is a small low island separated from the mainland on all sides by water of more than 400 fathoms : it must therefore be considered an oceanic as distinguished from a continental island. 1 Further to the north, and off the coast of Valencia, we have the Balearic Islands, namely, Majorca, Minorca, Iviza, and Formentera. These also must be considered oceanic islands, and indeed two groups of oceanic islands. Iviza and Formentera are isolated both from the Spanish coast and from the other two islands by water of over 300 fathoms depth ; Majorca and Minorca are connected by a bank with no more than 50 fathoms of water on it. Thirty miles east of Minorca there are more than 1400 fathoms ; beyond that there are no soundings between the Baleares and the large and important group of Corsica and Sardinia. These Islands are continental, being connected with the Italian main land by the bank on which Elba occurs, and which is covered by little over 50 fathoms of water. The Straits of Bonifacio, which separate Corsica from Sardinia, are also quite shallow, so that Corsica and Sardinia may be looked on as a secondary peninsula attached to the Tuscan 1 Continental islands are those separated from the mainland by comparatively shallow seas, generally under 100 fathoms. shore of Italy by a shallow bank not more than 15 or 20 miles broad, the deep water coming close up all round it. Almost the same maybe said of Sicily, including the Malta group, but excluding the Lipari group, which is purely vulcanic. From Cape Passaro, in the south-east end of Sicily, a line can be drawn connecting it with the town of Tripoli, and without passing over water of more than 300 fathoms. As has already been said, the west end of Sicily is connected with the coast of Tunis by a ridge in no part covered by more than 200 fathoms of water. Between these two ridges lies a small but comparatively deep basin of 600 to 700 fathoms. At the western extremity of it lies the mountainous island of Pantellaria. The bank on which Malta is situated stretches for nearly 100 miles in a southerly direction from Cape Passaro in Sicily. Opposite, on the African shore, is a similar bank of much larger dimensions, on which are the small islands Lampion and Lampedusa belonging to Italy. In the deep channel between them and Malta is the small but lofty island Liniosa. It is entirely volcanic, with an extinct crater on its north-eastern side, and three smaller ones to the south ward. It resembles the Lipari group off the north coast of Sicily, which rise abruptly out of deep water, being connected by no bank either with the African or the Sicilian coasts. Some of the Lipari group are still active, Stromboli and Vulcano being of the number. Off the south coast of Sicily, and between it and the island of Pantellaria, occurs the famous Graham s shoal, the remains of what was for a few weeks an island. - The deepest water of the Mediterranean is found in its widest part between Malta and Crete, and the deep water comes close up to the Italian and Greek coasts, while on the African shore the water shoals more gradually. In the Strait of Messina, close to Beggio, there are depths of over 500 fathoms, and similar depths are found inside gulfs such as those of Taranto (nearly 1000 fathoms), of Corinth, Kalamata, and others. Also all through tlje yEgean in its many bights and channels very deep water is met with ; in the Sea of Marmora we have 500 fathoms, and in the Black Sea over 1000 fathoms. All along the south coast of Asia Minor the water is very deep, and the large islands of Cyprus and Crete are both separated by very deep water from the mainland. If we take the eastern basin, and run along its western and southern coasts from the mouth of the Po along the shore of Italy, Sicily, and Africa to the mouth of the Nile, and even further along the Syrian shore, we do not find a single off-lying island of any importance except the Malta group, while all along the eastern and northern coasts from Trieste to Asia Minor the coast is deeply indented, and the water broken up by many large and important islands. These islands are grouped along the west coast of Turkey and Greece, and irregularly throughout the yEgean. The east coast of the Adriatic is studded with islands and inlets, and resembles in this respect the yEgean ; the west coast, on the other hand, is low, and the water off it shallow, and there are few harbours. The Adriatic stretches in a north-westerly direction for about 460 miles from its entrance between &quot; With regard to its appearance and disappearance Admiral Smythe (Mediterranean, p. Ill) says : &quot;It seems that, as early as the 28th of June 1831, Captain Swinburne, in passing nearly over the spot, felt several shocks of a sea-quake, proving that the cause was then in operation ; but on the 19th of the following July the crater had accumulated to a few feet above the level of the sea, and was in great activity, emitting vast volumes of steam, ashes, and scoria?. From that time it gradually increased in all its dimensions till towards the end of August its circumference was about 3240 feet and its height 107 ; then from October various changes took place, and it entirely dis- appeare 1 in December.&quot; Since that time it has changed considerably. In 1863 the least water on it was 15 feet. It has two heads close to gether, and at the distance of about 20 yards all round there are from 7 to 9 fathoms of water.