Chapter 12 of 18 · 3902 words · ~20 min read

Part 12

Lakes are of different kinds. Some are mere tanks which receive the first outpourings of springs, others consist of basins or reservoirs which occur in the line of a river’s course; some consist of basins or cavities, into which rivers flow, but which, on account of their depression or their mountainous cincture have no outlets; lakes are also formed in the craters of extinct volcanoes; and some lakes are periodic, or subject to have their basins alternately empty and full of water.

MOUNTAIN LAKES, which are valleys or chasms filled by streams, are long and narrow, rarely of extensive area, but often of great depth. Examples of this class are found in Lakes Champlain and George, among the Appalachian Mountains; Lakes Constance and Geneva, on the northern side of the Alps; and Lake Maggiore and Lake Como, on the south side; all of which are renowned for the loveliness of their shores, or the grandeur of the surrounding mountain scenery.

Lake Maggiore, which is hardly three miles wide, is, according to Italian engineers, 2,623 feet deep--more than double the depth of Lake Superior--its basin reaching 1,936 feet below the sea level.

The forms of mountain lakes are very irregular, for the water often covers several contiguous and connected valleys. This is the case in Lake Como, which has two long arms; and Lakes Lucerne and Lugano, each of which fills four distinct valleys, meeting one another nearly at right angles.

LAKES IN PLAINS. The lake basins in plains and plateaus are, usually, simple depressions in a comparatively uniform surface. The lakes are, therefore, often of great size, broad in proportion to their length, but of little depth compared with their area.

The largest lakes of the globe--the Caspian and Aral seas, and the great North American and African lakes--and the largest in Europe and South America, all belong to this class. Their vast expanse, together with the tameness of their shores, deprives them of the picturesque beauty of mountain lakes.

CHARACTERISTICS OF SALT LAKES. Numerous lakes in the interior of the continents, though receiving affluents, have no outlet. Their waters are chiefly lost by evaporation, though some portion may be absorbed by the sandy soil.

The surfaces of the continents having been the beds of the primeval oceans, the presence of salt in the soil is a natural consequence.

FAMOUS SALT LAKES. The Great Salt Lake of Utah, in the Great American Basin, is one of the finest examples of its class. The Caspian and Aral seas, at the bottom of the vast depression between Europe and Asia, are the most extensive salt lakes. The former has about four times the area of Lake Superior; and the latter is a little larger than Lake Michigan.

The Caspian, though receiving the Volga, the largest river of Europe, evaporates so much water that its surface is about 83 feet lower than that of the Mediterranean, varying with the seasons. Many lakes in its neighborhood disappear entirely in the heat and drought of summer, leaving their beds covered with a crust of pure white crystalline salt.

THE REMARKABLE DEAD SEA, in Syria, is a lake in which the salt has accumulated until the water is converted into a heavy brine. It may be the remnant of an ancient sea of much greater extent, which has been gradually reduced in size by the excess of evaporation over the supply of water in its basin.

This celebrated body of water lies in the deepest part of a long chasm or valley, which is sunk not less than 4,000 feet below the level of the surrounding country. The surface of the lake is 1,286 feet, and its bottom 2,500 feet, below the level of the Mediterranean.

Its feeder, the river Jordan, flows almost throughout its entire course below the level of the sea, the only known instance of the kind. The beautiful lake of Tiberias, the scene of so many of the miracles of Jesus, which is but an expansion of the Jordan in its upper course, is about 650 feet below the surface of the Mediterranean.

HOW THE LAKES ARE DISTRIBUTED OVER THE GLOBE

Lakes are most numerous in the central and northern portions of Asia, Europe and North America. The southern continents, except Africa, have comparatively few.

ASIA is pre-eminently the continent of salt lakes. They occur in countless numbers, both in the steppes north of the Caspian and Aral, and in all the interior plateaus. Lakes of fresh water are also found among the Altai Mountains and adjacent chains. Lake Baikal, one of these, is the largest mountain lake known, being nearly 500 miles long.

EUROPE. The most characteristic and celebrated lakes are those which adorn the Alps of Switzerland and Scandinavia, and the less lofty mountain chains of the British Isles. But the largest lakes are found in the low lands and slight swells which surround the Baltic Sea, in western Russia and Sweden. Lakes Ladoga and Onega in Russia, and Wener and Wetter in Sweden, are the largest in Europe.

NORTH AMERICA is peculiarly rich in great lakes. No continent presents a more remarkable series than that which stretches from northwest to southeast, through the central plains, along the line of contact of the oldest geological formations of the continent. This series includes Great Bear and Great Slave lakes, Athabasca and Winnipeg, and the five great lakes of the St. Lawrence, with many of less area.

Innumerable small lakes are scattered throughout the middle portions of the central plain, and the northern and less regular part of the Appalachian mountain region; but south of the parallel of Lake Erie there is an almost entire absence of lakes, whether large or small.

[Illustration: =Relative Size of Lakes of the Western Hemisphere=]

PRINCIPAL SALT-WATER LAKES OF THE WORLD

[Illustration: =Relative Size of Lakes of the Eastern Hemisphere=]

PRINCIPAL FRESH-WATER LAKES OF THE WORLD

AFRICA. The great plateau lakes are typical of the continent. The Victoria Nyanza and Albert Nyanza, feeding the White Nile; Tanganyika, whose outlet is unknown; Tzana, at the head of the Blue Nile; and Lake Nyassa, in the Zambezi basin, all rest on the high plateaus of Central Africa. Lake Tchad alone, among large African lakes, is surrounded by low plains.

WATERFALLS AND RAPIDS. The variations in the slope of a river-bed, arising from unequal erosion, or from the original irregularities in the surface, give rise to rapids and falls.

The first occur where an increased slope causes the stream to flow with more than its average velocity. The second are caused by nearly perpendicular rocky walls, down which the foaming water descends in picturesque cascades, or imposing cataracts.

The famous “Cataracts of the Nile” are merely rapids which impede but do not entirely obstruct, the navigation as cataracts must. The so-called Falls of St. Anthony, in the upper Mississippi, and the rapids of the St. Lawrence, above Montreal, are among the finest rapids in American rivers.

The highest falls are in the upper course of rivers, in mountainous regions; the greatest and most imposing, in their middle course.

The Niagara Falls exhibit a most important industrial utilization of water power. The Falls of St. Anthony in the Mississippi, the Falls of Foyers in Scotland, the Rhine falls, the Rhone falls of Bellegarde, and the innumerable waterfalls of Scandinavia, Switzerland, and similar mountainous lands, are all utilized in this way. It has been proposed to convey power generated at the Victoria falls of the Zambezi to the Rand goldfield of the Transvaal, and a scheme for this is now being prepared.

=FAMOUS WATERFALLS OF THE WORLD=

NAME LOCATION HEIGHT (FEET) =Bridal Veil= California 900 =Foyers= Great Britain 205 =Gastein Falls= Austria 469 =Gavarnie= Pyrenees 1,400 =Genesee= New York 95 =Grand Falls= Labrador 2,000 =Great Falls= Montana 500 =Hay River= Alaska 200 =Kaieteur Falls= Guiana 740 =Krimmler Falls= Austria 1,300 =Kukenam Fall= Guiana 1,500 =Maanelvan= Norway 940 =Minnehaha= Minnesota 50 =Missouri= Montana 90 =Montmorenci= Quebec 265 =Multnomah= Oregon 850 =Murchison= Africa 120 =Nevada Falls= California 600 =Niagara= New York 165 =Oroco Falls= Monte Rosa 2,400 =Rjukanfos= Norway 804 =Roraima Fall= Guiana 2,000 =Rukaufos= Norway 513 =St. Anthony= Minnesota 80 =Schaffhausen= Switzerland 100 =Seven Falls= Colorado 266 =Shoshone= Idaho 210 =Skykjefos= Norway 700 =Snoqualmie= Washington 268 =Staubbach= Switzerland 1,000 =Stirling= New Zealand 500 =Sutherland= New Zealand 1,904 =Takkakaw= British Columbia 1,200 =Tequendama= Colombia 475 =Tessa Falls= Austria 541 =Twin= Idaho 180 =Velino Falls= Italy 591 =Vermafos= Norway 984 =Vettisfos= Norway 950 =Victoria Falls= Zambezi 400 =Voringsfos= Norway 600 =Yellowstone (upper)= Montana 110 =Yellowstone (lower)= Montana 310 =Yguazu or Iguazu= Brazil 210 =Yosemite (upper)= California 1,436 =Yosemite (middle)= California 626 =Yosemite (lower)= California 400

[Illustration: =FAMOUS WATER PICTURES OF THE NEW AND OLD WORLD=

Niagara in winter presents a picture of frozen grandeur equaled nowhere else in the world.]

[Illustration: The Rhine at Schaffhausen, Switzerland, rushes over rugged rocks on its way down from the highlands into the lovely and historic valley it has carved for itself on its way to the sea.]

[Illustration: =FAR-FAMED WATERFALLS THAT HAVE INSPIRED TRAVELERS AND WRITERS=

1. The NIAGARA FALLS and rapids form one of the most impressive spectacles in the world. The Niagara River, which is the sole outlet of the great lakes, pours itself in two vast sheets over a precipice about 160 feet high. Goat Island, which is situated on the lip of the falls, divides the cataract into two sections--the Horseshoe, or Canadian fall, which is by far the more majestic, and the America fall. It has a descent of 158 feet and the American fall of 167 feet. The volume of water which sweeps over this immense chasm is about 15,000,000 cubic feet per minute. The limestone edge of both falls is wearing away in the center, the Canadian fall now being V-shaped, and the American fall showing the same tendency, although its process of recession has begun more recently. For some distance below the falls there is smooth current, the mass of water which pours over the precipice sinking and only coming to the surface two miles below, where the rapids, more magnificent and wilder than those above the falls, begin, and culminate in the rapids of the Upper Whirlpool. Lower down the river is the whirlpool itself, where a sharp turn sends the waters hurling against the Canadian side; they then sweep round in a gigantic circle before they find a vent at right angle with their former course. The sight of the falls is equally awe-inspiring from the bridge on the lip of the fall, from the boat which plies from shore to shore below the cataract, or from the Cave of the Winds, reached from Goat Island. Although in summer the magnificence of the sight is extraordinary, it is in winter, when the wizardry of the frost is upon it, that it is superlatively beautiful. The falls were first discovered by Father Hennepin in 1678.

2. The FALLS OF JUANACATLAN (_hoo-ă-nă-kwt-lăn_), Mexico, are located near the island city of Guadalajara (guă-dă-lă-hă´ră) on the Rio Grande de Santiago. Though only 70 feet in height they are more than 600 feet wide, and as known as the “Niagara” of Mexico.

3. The CATARACTS OF IGUAZU (_e-gwă´soo_) on the frontiers of Brazil, Argentina and Paraguay. These falls, situated in a remote wilderness, far from civilization, are a veritable fortress in protecting the peace-loving peoples on their borders. They constitute a series of falls extending over three miles, and more than 200 feet in height, and of magnificent scenic beauty. Their energy is estimated to be about 14,000,000 horse-power, or almost three times that of Niagara.

4. The YOSEMITE (_yo-sem´i-tee_) FALLS of California, are highest and probably the most remarkable of their class. They descend on almost perpendicular ledge of rocks 2,600 feet high to the bottom of the Yosemite valley, forming three separate cataracts. The first fall is 1,600 feet sheer descent. Then comes a series of cascades, partly hidden, 600 feet downward, and a final leap of 400 feet. Seen from afar, the Yosemite Falls seem insignificant; but they are, in fact, 35 feet wide, and the shock of their descent is observed a mile away.

5. The STAUBBACH (_stoub´băk_) FALLS, in the Swiss Alps near Lauterbrunnen, descends a precipice of 980 feet, and is reduced to spray like a misty veil before reaching the bottom. It is the highest unbroken fall in Switzerland, and the most noted.

6. The GREAT FALLS OF THE YELLOWSTONE, though not so high, vie with the Yosemite in striking beauty. These famous falls plunge from a height of 360 feet into the abyss of a mighty chasm. At the point of descent, the waters of the Yellowstone suddenly contract from a width of 250 feet to 75 feet.

7. The BRIDAL VEIL FALLS of California, belong to the famous Yosemite Valley. Its waters, over 30 feet wide, leap from the granite rocks on the south wall of the Yosemite in two vertical descents aggregating over 900 feet. The first fall covers a distance of 600 feet, then the waters rushing over a sloping pile of jagged rocks drops a perpendicular distance of 300 feet more. From the chief points of view it seems to make but one plunge, in an unbroken descent similar to the Staubbach, but carrying a much greater volume of water. Frequently the wind swings the great plume of water from the face of the cliff and waves it like a scarf or veil. At sunset rainbows with an indescribable radiance bejewel its foam and the glistening leaves surrounding it.

8. The REICHENBACH (_ri´ken-băk_) FALLS near Meiningen, Switzerland, comprise five fine cascades in the Reichenbach River. The most gorgeous of these, known as the Upper Fall, makes a huge leap of 300 feet into a deep rocky basin, which then continues in several foaming and plunging cascades in general aspect not unlike the Niagara gorge.]

THE OCEANS OF THE WORLD AND THEIR MYSTERIES

[Illustration: =THE LAND AND WATER HEMISPHERES=]

The Oceans consist of one great fluid mass, and in extent covers three times the area of the dry land. There is also about three times as much land to the north of the equator as there is to the south of it. Though the waters of the ocean surround the land on every side, yet they are broken up into certain areas by the arrangement of the land portions, and to these various parts we give particular names.

The Atlantic Ocean, lying between the western shores of Europe and Africa and the east coast of America.

The Pacific Ocean, lying between the west coast of America and the east coast of Asia.

The Indian Ocean, lying between the south of Asia and the Antarctic circle.

The Arctic Ocean, lying within the Arctic circle.

The Antarctic Ocean, lying within the Antarctic circle.

VAST EXTENT OF THE OCEANS

THE ATLANTIC is the most branching of the oceans, and is especially distinguished by the number and great size of its inland seas. Two of these, the Mediterranean Sea and the Gulf of Mexico, lie in the warm regions; and two, Hudson Bay and the Baltic Sea, in colder latitudes.

The broader seas are represented by the Caribbean Sea, within the tropics and the Gulf of St. Lawrence and the North Sea in temperate latitudes. The Gulf of Guinea, and the Bay of Biscay, are examples of the more shallow coast waters.

THE PACIFIC is particularly rich in vast border seas, a continuous series of which lines the Asiatic and Australian coasts. Among these are the Behring Sea, enclosed by the peninsula of Alaska and the Aleutian Islands; Okhotsk Sea, enclosed by Kamchatka and the Kurile Islands; the Sea of Japan, and the North and South China seas; and the Arafura, Coral, and New Zealand seas, on the Australian Coast.

Only two inland seas of considerable size--the Gulf of California in North America, and the Yellow Sea in Asia--mark this entire basin.

THE INDIAN OCEAN is characterized by gulfs, two of which form the entire extension of the basin; namely, the Gulf of Bengal, and the Arabian Sea. It has also two inland seas of considerable extent, the Red Sea and the Persian Gulf, isolating the peninsula of Arabia from the adjacent continents; but border seas are wholly wanting in the Indian Ocean.

THE ARCTIC OCEAN is a partially enclosed sea, which a comparatively inconsiderable rise of the sea-bottom would convert into a true Mediterranean. Three openings connect it with the Pacific and Atlantic Oceans, namely, Behring Straight (narrow and shallow), Davis Straight, and the broad expanse of water lying between Norway and Greenland. Of these, the last is by far the most important, for through it the warm waters of the Gulf Stream find access to the Polar basin, and keep the sea free from ice throughout the year. This current is supposed to flow feebly along the coast of Siberia, until, deflected by the land, it becomes merged in the cold counter-currents which, passing along the eastern coasts of Greenland and Labrador, carry immense masses of ice into the Atlantic.

[Illustration: =PICTORIAL DIAGRAM OF THE STRUCTURE OF THE EARTH IF THE WATERS WERE REMOVED=

Ridges, mountains, plateaus, which may represent submerged continents of the past, and many an abyss that exceeds in depth the height of the highest mountains, are shown above. The shallow coasts, marked by the lightest shade, are part of the present Continental Shelf, and do not exceed six hundred feet in depth. Beyond this shelf, as a rule, the oceans rapidly attain great depths. Our knowledge of the ocean bed has been obtained from the extensive soundings.]

THE ANTARCTIC OCEAN is situated about or within the antarctic circle. The great Southern Ocean is that part of the ocean which surrounds the world between the latitude of 40 degrees south and the antarctic circle. The northern portions of this band are often called the South Atlantic, South Indian and South Pacific, while the southern portions are usually called the Antarctic Ocean. The average depth of the continuous ocean which surrounds south polar land is about two miles; it gradually shoals toward antarctic land, which in some places is met with a short distance within the antarctic circle. Life is abundant in the surface waters, and at the bottom of the ocean.

HOW THE FLOOR OF THE OCEAN APPEARS

As a rule the sea is shallowest near the land, though in a few cases there is a sudden descent to a great depth at a very short distance from the coast. Lowlands have usually shallow seas near the coast, and highlands deep water.

Along the American shores, in the latitude of New York, the depth, for a distance of more than 100 miles, is less than 600 feet; then suddenly the bed descends, by a steep slope, to the depth of 6,000 or 9,000 feet. After a comparatively narrow interval, a second terrace descends to the main basin, from 15,000 to 18,000 feet deep.

The bottom of the trough of the ocean, in general, is equally varied with that of the land surface of the globe, forming mountains, hills, valleys, tablelands, etc. In many parts these marine mountains reach above the surface and form islands. On the table land extending across the Atlantic between Newfoundland and Ireland is laid the submarine-telegraph cable which connects the two hemispheres.

THE DEPTH OF THE OCEANS. The average depth of the Pacific Ocean has been estimated at between 15,000 and 18,000 feet, which is slightly greater than that of the Atlantic. The deeper portions may be learned on reference to the map. The western portion of the North Pacific in particular shows some very deep depressions. To the east of Japan lies a long deep trough which in one part has furnished the sounding of nearly five and one-half miles. This abyss is often called the Tuscarora Deep. South of the Ladrone Islands, in the Caroline Archipelago, there is also a deep abyss where an English ship, the _Challenger_, obtained a sounding of nearly 27,000 feet. In the Pacific soundings of over 30,000 feet have been made.