point or line where a river runs; often of considerable magnitude, and fed by the mountain

streams.

The larger plains, which are neither interrupted by mountain or river, are necessarily sterile, and consist generally either of hard, unproductive clay land, or loose sand, as in the torrid regions of Africa; the central parts of Persia, &c. 2. Of the Ocean and Waters of the Earth.The immense body of terrestrial waters is divisible into two great basins. That which may be denominated The GREAT ATLANTIC basin; and The GREAT PACIFIC, or Grand Ocean, as it has been called; for it has strictly no particular relation to any quarter of the globe.

I. The Great Atlantic basin will include the Northern Frozen Ocean, or Arctic Sea, surrounding the North Pole, and washing the northern extremities of both the old and new continents. Its other branches in this part of the world are the White or Lapland Sea, and Baffin's Bay. This noble expanse of water now separates Europe and Africa from America, and is limited on the south by a line drawn from the Cape of Good Hope to Cape Horn. The portion of this ocean north of the tropic of Cancer to the polar circle is the North Atlantic, that south of the tropic of Capricorn the South Atlantic, and that included between the tropics the Equinoctial Atlantic.

The branches of the North Atlantic on the side of the old continent are, 1. The Sea of Norway, comprised between the coasts of Norway and Iceland, and the Zetland and Ferroe Islands, extending from the Polar Circle to the sixtieth degree. 2. The British Sea, between Great Britain and the continent from the sixtieth degree to the Strait of Dover. The name of North Sea given to this branch of the Atlantic, first probably by the Dutch, in whose country alone it is applicable, has been generally adopted by the French and English, particularly in their sea charts; it is also frequently designated by its ancient name of the German Ocean. 3. The Baltic, which communicates with the British Sea by the Scagerack and Cattegat, the former of which may be confined to the space between the south coast of Norway and the north-west coast of Jutland, which extends nearly north-east and south-west; leaving the Cattegat as a discriminating turn for the channel between the east coast of Jutland and the coast of Sweden. 4. The English Channel, separating England and France. 5. The Irish Channel, sometimes improperly called the Irish Sea, separating Great Britain and Ireland. 6. The Bay of Biscay, washing but twenty leagues of the coast of Biscay, while it has 120 leagues of the coast of France, should receive the name of the Gulf of France. 7. The Mediterranean is the last branch of the North Atlantic on the side of the old continent, and the Equinoctial Atlantic on this side has only the Gulf of Guinea, between capes Palmas and Negro.

On the American side of the North Atlantic, the branches are, 1. Davis's Strait, separating the southern extremity of Greenland from the continent of America, and forming the entrance into the Bay of Baffin, Barrow's Straits, &c. 2. Hudson's Bay, which is properly a Northern Mediterranean sea.

On the American side of the Equinoctial Atlantic are the Gulf of Mexico; and the Carib bean Sea, running between the West India islands and the continent of America.

Round the promontory of Africa is the Indian Sea, one of the most extensive and important branches of this division of the ocean; bounded on the west by the east coasts of Africa and Arabia, on the north by India, on the east by the west coast of New Holland, or Teria Australis, and the Great Asiatic Archipelago, and on the south by a line drawn from the Cape of Good Hope to the south-west point of New Holland. The branches of this sea on the west are, 1. The Channel of Madagascar, or of Mosambique, separating the island of Madagascar from the continent. 2. On the north-west the Great Gulf of Arabia, or sea of Oman, the limits of which are capes Guardafui and Comorin. The Red Sea and Gulf of Persia are branches of the Great Gulf of Årabia.

The north-east extremity of the Indian Sea forms the Bay of Bengal, which with more propriety would be named the Gulf of Indostan ; its limits are the south point of Ceylon and the north-west point of Sumatra. On the east the Indian Sea forms a large gulf between the Sunda Isles on the north, and New Holland on the south.

To the east of the Indian Sea, and within the tropics, are several portions of the ocean, forming seas enclosed by the Malay Archipelago; as the China Sea, the seas of Java, Celebes, and the Moluccas. The collective name of the Sunda Sea has been given to the last three.

II. The second great basin we have noticed separates Asia from America. It has the general denominations of South Sea and Pacific Ocean; but the more appropriate name of Grand Ocean has been proposed for this great basin by M. Fleurieu. The great divisions of this ocean are, 1. The Great Northern Ocean, extending from the Arctic Circle to the Northern tropic. 2. The Pacific, or Grand Equinoctial Ocean, included between the tropics. 3. The Great South Sea, extending from the southern tropic to the south cape of Van Diemen's Land and Cape Horn.

The Great Northern Ocean has several branches; the first of which to the north is comprised between the north-east extremity of Asia, the north-west extremity of America, and the Aleutian Islands, for which has been proposed, with great propriety, the name of Bhering's Basin, from the navigator who first visited it. On the coast of Asia to the north-west it forms the Gulf of Anadyr, and on that of America to the south-east the great Bristol Bay of Cook. On the coast of Asia to the south, we now meet a series of internal seas from Kamtschatka to Formosa; the first bounded by Kamtschatka on the east, and by Russian Tartary, or Siberia, on the west and north, is named by the Russians, the Sea of Ochotsk, from a miserable town and river on it, and the Sea of Lama by the Tongouth Tartars who inhabit its shores; in some geographies it is also called the Sea of Kamtschatka; as more appropriate, we propose to name it the Sea of Tartary, and to leave that of Gulf of Ochotsk to its western extremity.

The second of the interior chain of seas, called

the Sea of Japan, is bounded by Chinese Tartary on the west, by the island of Sagalin on the north, and by the Japan Islands on the east and south it has been called, with propriety, the Sea of Japan.

Southward this sea communicates with a third internal sea by the Strait of Corea. The gulf which it forms on the north, between Corea and China, is called by the Chinese the Yellow Sea (Hoang-hai), from the muddiness of the water, but which may with more propriety be named the Gulf of Corea. The Chinese (from the clearness of its waters) give the name of Blue Sea to the portion of the sea of Corea, between the south coast of the Peninsula and the island of Formosa.

The Pacific or Grand Equinoctial Ocean has several branches included between the chains of islands from Formosa on the north-west to New Caledonia on the south-east, which Mr. Tuckey has arranged under the following nomenclature. 1. The space between Formosa and the Philippines on the west, the chain of Mariannes on the east, and the Pelew Islands on the south, he proposes to call the Philippine Sea. 2. The space between the chain of New Philippines or Carolinas (of which the Pelew Islands are the western extreme) on the north, Lord Mulgrave's range on the east, and New Guinea and Solomon's Islands or the Papua Archipelago on the south, he calls the Papua Sea. 3. To the space of the Grand Ocean comprised between the Papua Archipelago on the north, Terra Australis or New Holland on the west, the New Hebrides, New Caledonia, and New Zealand on the east, he gives the name of the Sea of New Holland, or of Australia. At its north-west extremity, it forms the Gulf of Louisiade of Bougainville, which by Torre's Strait communicates with the Gulf of New Holland and the Indian Sea.

On the coast of America south of Behring's basin the Grand Ocean has but the three gulfs formed, 1. By the peninsula of Alaska on the west, and the continent on the north and east. 2. That formed within the peninsula of California, called by the Spaniards the Vermilion Sea, and sometimes the Gulf of California. 3. The Gulf of Panama, between North and South America. The Great Southern Ocean and the Southern Frozen Ocean may be considered as the last grand divisions of this basin.

Those

Lakes form, from their occasional magnitude, the next topic of our consideration. which have no visible communication with the sea, and form the final receptacle of rivers, are the Caspian and the Lake Aral, already noticed, in the heart of Asia. Similar ones have been reported to occupy part of the interior of Africa, but they have not yet been found. The great lakes of North America have already been adverted to, in our article of that name; it may suffice to notice here that the St. Lawrence sweeps through then all; and that South America presents us with no lake of comparative magnitude. That of Chucuito or Titiaca, in Peru, is the only one worth noticing.

The great rivers of the earth descend usually from the upper part, and fall down the opposite

sides of a chain of mountains. Their channels are broad or steep in proportion to the quantity of water, and the level of the district through which they run. The principal rivers that have great periodical inundations, are, the Nile, the Senegal, the Euphrates, the Indus, the Ganges, the rivers of Pegu, of Siam, and of Cambodia, the Amazons and Plata, and, in general, all the great rivers within the tropics; the cause of these inundations being the heavy periodical rains in the equatorial regions. In several of these large rivers a phenomenon is observed, caused by an extraordinary strong ascending tide repelling the current of the river, when the conflict produces a mountainous ridge of water, capable of sweeping large ships from their moorings.

Many great rivers of slow current form bars of sand across their mouths, as the Nile, the Senegal, &c.; while others rush with such rapidity, and volume to the sea, that they freshen and discolor its waters for many leagues; as the Danube, the Plata, &c.

The velocity of rivers depends more on the weight and quantity of the anterior waters than on the declivity of their beds. Hence the stream of a river, whose bed has twice the declivity of another, does not move with twice the velocity only, but with treble or quadruple that velocity, according to the volume of its waters. If, therefore, we intend to give greater velocity to a river or canal, by deepening its bed, the greatest declivity should be near the head, diminishing almost to a cypher at its mouth, as is naturally the case near the mouths of large rivers, where, though the declivity of the bed is imperceptible, the velocity of the stream is increased by the accumulated weight of the anterior waters: some rivers are even known to acquire so rapid a movement, as not only to retain their velocity across a considerable extent of level ground, but also to surmount an eminence without spreading much.

The following is major Rennell's estimate of the proportional courses or lengths of the great rivers of the globe, taking the Thames as unity: EUROPE. ASIA.

Waters impregnated with saline and mineral particles, warm springs, &c., are so few, and have generally such remarkable local peculiarities, that we at once refer the reader to their alphabetical places for a description of them. For the phenomena of tides and currents, see TIDES and SEA CURRENTS.

3. Of the atmosphere.-To the articles AIR, ATMOSPHERE, and CLIMATE, we may also refer the reader for every thing important in the consideration of this great element of our earthly sys

tem. M. Humboldt's isothermal lines, the greatest modern improvement in the consideration of climates, are inserted in the last article; the manner in which these, however, affect congelation, is by no means uniform. Radiation and various local circumstances must be taken into account. Thus on the side of Chimborazo, near the equator, the line of perpetual congelation is found to be at the height of 15,746 feet; and in the 20° of north latitude, on the Mexican mountains, 15,090 feet, giving a difference in 20° of latitude of only 656, when professor Leslie's table would

teach us to expect 1729 feet. In Tartary, again, according to the late observations of captain Webb, fine pastures are found on the Sutledge river at an elevation of 15,000 feet above the level of the sea; while, on Mont Blanc, the line of perpetual snow is marked by Saussure at 6640 feet. At 16,814 feet, not a vestige of snow appeared, according to the foregoing writer, on the Nittie Pass of the great Himalaya chain. The principal circumstances that had been previously observed on the subject, are thus brought together by baron Humboldt:

4. Of the animal tribes.-Over a consideraple portion of the globe we find the Linnæan vermes diffused; while the zoophytes and marine insects, those particularly which produce coral, are restricted to particular regions; the latter, generally, to the torrid zone of the Pacific and Indian oceans. The haunts of insects, and the brilliant plumage of the feathered tribes, belong to the same warm climates. The former are both more numerous and of incomparably more annoying qualities in the torrid, than in temperate zones. Here they lay waste whole regions over which they pass, driving the inhabitants before them, with the fury of a tempest; and particularly wherever forests and moisture abound in these climates, they swarm in countless myriads. In these regions also the

reptile and lizard tribes arrive at a fearful perfection. Here also fish of the largest size, the most ferocious habits, and most brilliant colors are found. The shark of the tropics is said to be unequalled in rapacity in any other region, and to rival even the wild beasts of the forest in that respect. Migratory fishes abound chiefly in the northern regions, and descend toward the equator. In the higher latitudes of those regions, also, the finny tribes attain their greatest magnitude.

Birds in the peculiarity of their food, as well as their plumage, indicate the regions to which they belong. The vulture and eagle haunt the highest peaks over which animal life is ever found to hover-the Cordilleras of the Andes, and the summits of the Alps and the Appenines;