EUROPE 083 miles long and two miles oread, was endyked in 1853, and that islands are being formed further out towards the sea. The Baltic shores of Germany display the same phenomena of local gain and loss ; and there is more than a suspicion that the whole line lies along an area of subsidence. In the western section the inroads of the sea have been very extensive : the island of Riigen would no longer serve for the disembarkation of an army like that of Gustavus Adolphus; Wollin and Usedom are growing gradually less; large stretches of the mainland are fringed with submerged forests ; and at intervals the site of well-known villages is occupied by the sea. Towards the east the great rivers are successfully working in the opposite direction. In the gulf of Dantzic the alluvial deposits of the Vistula cover an area of 1GOO square kilometres or G15 square miles; in the 13th century the knights of Maricnburg inclosed with dykes 900 sq. kil., or 346 sq. m., and 180 sq. kil., or 69 sq. m., were added in the course of the 14th. The Memel is silting up the Kurische Haff, which, like the Frische Haff, is separated from the open sea by a line of dunes comparable with thoae of the Landes in France. A large amount of evidence has gradually accumulated in favour of the hypothesis that the Scandinavian peninsula is in process of elevation. Within the last two centuries fiords have been left dry or broken into lakes, reefs have been turned into islands, bays into pasture grounds. M. Reclus has pointed out that the presence of certain beds of oysters goes to show that the lakes Malar, Hjelmar, and Wener are remains of a channel which at no distant date communicated between the Baltic and the North Sea ; but the facts of marine distribution, as stated by Forbes, are rather against the opinion of Celsius, that there was also a connexion with the Arctic Ocean as late as the time of the first Roman exploration. At Pitea, in the Gulf of Bothnia, the land is said to have gained a mile in 45 years, and at Lulea a mile in 28 years. 1 It is only right, however, to mention that the state ments made in. the preceding paragraphs in regard to areas of subsidence and elevation are by several geologists con sidered to be of very dubious validity. The data, they believe, are much too slight and fragmentary for the con clusions, and some of the most important are open to quite different interpretations. The so-called strand or coast-lines of the Scandinavian peninsula, for example, are still the subject of keen controversy among northern in vestigators, and a large polemical literature is the result. Till the question as to the origin of these remarkable appearances is finally settled, the recent elevation of the peninsula must be regarded as little more than a provi sional hypothesis. 2 The changes briefly indicated above take place so gradually for the most part that it requires careful observa tion and comparison of data to establish their reality. The Dutchman does not feel the subsidence of his well-defended fiats, and the Norwegian is quite unconscious that he is being raised along with his pine-clad hills. It is very different with those changes which we usually ascribe to volcanic agency : they force themselves on the attention, and find a permanent place in the memory of the people. And yet it is only the scientific registration of the phenomena which gives any accurate idea of their frequency and extent. To the popular apprehension Europe is a fairly stable portion of ttrra Jirma, and we are accustomed to contrast the uncomfortable tendency to 1 Compare Howorth " On Recent Elevations of the Earth s Surface in the Northern Circunipolar Region," inJovr. Roy. Geog. Soc., 1873, and Adolf vou Hoff, Gcsch. d. Vcrand. d. Krdvberflackc, 1822, 1823, 1834. 2 Compare Keilhau On the Rise of Land in Scandinavia; Kjemlf, Om Skurlnysmarka, Ac., i S irye, 1872; Sexe, On yamle Strandlinicr i fast Klippe, 1874. oscillation exhibited by such a region as Colombia or Peru in South America. But it is not so stable as it appears. Besides the great outlying " hearth " of Iceland, there are four centres of volcanic activity in Europe all of them, however, situated in the Mediterranean. Vesuvius on the western coast of Italy, Etna in the island of Sicily, and Stromboli in the Lipariau group, have been familiarly known from the earliest historic times ; but the fourth has only attracted particular attention since last century. It lies in the Archipelago, on the southern edge of the Cyclades, near the little group of islets called Santoriu. The region was evidently highly volcanic at an earlier period, for Milo, one of the nearest of the islands, is simply a ruined crater still presenting smoking solfataras and other traces of former activity. The present crater of Santorin is subaqueous, but it has already raised a con siderable mass of material above the surface. The devasta tions produced by the eruptions of the European volcanoes are usually confined within very narrow limits ; and it is only at long intervals that any part of the continent is visited by a really formidable earthquake. There is little danger when the tremor has to be verified by glass cylinders on a sanded floor. Minor shocks, however, are exceedingly numerous. Dr Volger found that during the first fifty years of the 19th ceatury the average number per annum was, in Switzerland, no less than fifty ; and he indicates the following localities as halitudlcn Stossgebiete or areas of fre quent disturbance: (1) in the region of the Jura, the valley of the Birs to the S. of Basel, the valley of the Orbe, the Val de Travers, the valley of St Imier, the district at the confluence of the Aar and theLimmat, <tc.; and (2) in the Alpine region, the valley of the Durance and the Drac, of the Arc and the Isere, nearly the whole line of the Arve, the upper valley of the Rhone almost without interruption to the Lake of Geneva, part of the valley of Adige to the S. of Trent, and the valleys of the Drave and the Gail to the W. of their confluence. A table drawn up by Dr Suess registers about 116 earthquakes in Lower Austria from 1021 down to 1870, and of these 53 belong to the present century. 3 Of all European earthquakes in modern times, the most destructive are that of Lisbon in 1755, and that of Calabria in 1783; the devastation produced by the former has become a classical instance of such disasters in popular literature, and by the latter 100,000 people are said to have lost their lives. Calabria again suffered severely in 1865 and 1870. If Russia be left out of account, Europe may be gene rally characterized as a mountainous region, the ratio of highlands and lowlands being, according to Von Kloden s calculation, approximately as follows : Totul Area. English sq miles. Highlands. English sq. miles. Lowlands. English sq. miles. Continental portion, without j peninsulas and islands ... Greater peninsulas 2,740,100 835,715 587,412 641,286
2,152,688 194,429 Great Britr.iii and Ireland Other islands 115,913 64,733 60,125 47,857 56 rsa 16,881 In other words, the purely continental portion has 21 44 per cent, of highlands to 78 56 percent, of lowlands ; the peninsular portion 76 74 per cent, to 23 26 per cent.; Great Britain and Ireland 51 8 7 per cent, to 48/13 per cent.; and the remaining islands 73 -92 to 26 08. There are none of the individual mountains that attain more than a mode rate elevation if they are compared with the mountains of Asia and South America. Mont Blanc, the loftiest of all, has an altitude of only 15,781 feet, while M. Everest, iu See Zeitschrift der K. Academie zu Wien, 1874 and 1875, and
Petennann s Miltheilunqen, 1856.