Europe is bounded on the north and west by the Arctic and Atlantic Oceans ; on the south by the Mediterranean; on the east by the rivers Don, Wol ga, and Kama, and by the Uralian Mountains from the Kama • to the Arctic Ocean. These are the li mits most generally admitted. Some alterations have been proposed on the south-east side, with the view of making the boundary line correspond more accu rately with the physical divisions of the earth's sur face ; but as they have not obtained the sanction of geographers generally, the line that is best known seems entitled to the preference. The greatest length of the Continent of Europe is from Cape St Vincent to the Sea of Kara, in the direction of north-east and south-west, and is 3490 English miles. Its greatest extent from north to south is from Cape Matapan to Cape North, 2420 miles. Its greatest extent from east to west is on the parallel of 48°, from Brest to River Don, 2230 miles. The superfices of Europe, including the Azores, Iceland, Nova Zembla, and all the other islands belonging to it, is 3,422,000 Eng lish square miles.
The climate of Europe is distinguished by two pe culiarities. It enjoys a higher mean temperature than any of the other great divisions of the world, in the corresponding latitudes ; and it is not subject to such violent extremes of heat and cold. These advantages it owes chiefly to its numerous seas, in land bays, and lakes, which render its temperature similar to that of islands; and partly also, according to Humboldt, to its situation at the western extre mity of the greatest range of dry land on the surface of the globe ; the western sides of all continents being warmer than the eastern. Europe lies almost entirely within the temperate zone,, not more than one-four ' teenth part of its surface being within the arctic circle. Only a very small part of it is uninhabitable from cold, and it nowhere suffers much from excessive heat. The mean temperature at its southern extre mity, in the latitude of 36°, is about 66° of Fahren heit ; and at Cape North in the latitude of 71°, where the mean temperature is the cold is not greater than in the latitudes of 55 or 56 on the east coasts of Asia and America. Hence Europe is habitable at a higher latitude by 12 or 14 degrees than either of these continents. The following table, taken from Humboldt's Memoir on the Distribution of Heat (a , bridged in Dr Thomson's Annals of Philosophy, XI. 188), shows the difference in temperature between Europe and the eastern shores of Asia and America at the parallel of 10° : the difference is much greater at the parallel of more equally distributed through the different sea sons. As we advance from the coast eastward the mean annual temperature diminishes, but the heat of summer and the cold of winter increase. Thus Lon don has the same mean annual temperature as Vien na, but it has the summer of Petersburgh, and the winter is warmer than at Milan. The Mediterra nean, the Baltic, and inland lakes, produce the same effect as the ocean in an inferior degree. The two following tables are taken from Humboldt (Annals of Phil. XI. 188); the first shows the temperature of
the year, and the various seasons in places having the same latitude ; the second shows the different distri bution of heat through the various seasons in places having the same mean annual temperature.
The mountains of Europe are more numerous in proportion to its extent than those of the other great continents, but they are of less elevation than the mountains of America and Asia. The highest, and the most extensive chains in Europe, run generally in the direction of east and west, and are placed near its southern shores. The central mass of the Alps, with which all the other mountains in the south of Europe are connected, forms the summit of the continent, and determines the position of the surface, and the course of most of the rivers. From this central point the surface of the land descends to the sea by a series of valleys, skirted by subordinate chains. The three countries to the southward of the Alps and their branches, Greece, Italy, and Spain, consist of mountainous peninsulas Projecting into the Mediterranean. The countries to the west, north, and east of the Alps, which present more extensive plains and gentle declivities, are the seats of the three principal monarchies in the south of Europe. Austria, seated on the eastern declivity, rules over the countries watered by the Danube ; France oc cupies the western declivity, and the countries water ed by the principal streams that flow to the west ; and Prussia the countries watered by the streams that flow to the north. If we descend from the Alps to the seOn a western direction, the first valley we meet with is the level part of Switzerland between the Alps and Mount Jura, elevated from 1600 to 1800 feet above the sea; • the second, between Jura and the Cevennes, some hundred feet lower; and the third, and lowest, extends from the Cevennes to There is a difference of the same kind between the temperature of the sea-coasts of Europe and the interior. In islands, and on the sea-coast, the mean temperature of the year is higher, and the heat is the Atlantic. In a north and north-east direction, the first valley is Bavaria, the second Bohemia, both of which are completely enclosed by mountains; the third, consisting of Silesia, Brandenburg, and Po. land, terminates in the Baltic. In an eastern di rection the first valley is Austria, the second, Hun gary, both encircled with mountains; the third, Bul garia, extends to the Black Sea. South fiom the Alps we have first the valley of Lombardy, and then the narrow coast of Genoa. The vast plain occu pied by Russia, and the eastern part of the Swedish peninsula, may be considered as a prolongation of the valley of Prussia and Poland, extending to the Dofrines on the west, the Uralians on the east, and Mount Caucasus on the south. Thus, in a ge neral point of view, the elevation and declivity of the large plains of southern Europe bear a certain rela tion to the position and distance of the central mass of the Alps.