QUESTIONS ON THE MAP.

EXTENT AND OUTLINE OF THE CONTINENTS.

Which of the two continents is the largest? Which extends
farthest north? How many degrees nearer than the other to
the north pole does it lie? Ans. About 60. Which extends
farthest south? How many degrees is it nearer than the
other to the south pole? Ans. About 19. Which, then, has
the greatest range of latitude, and how many degrees differ-
ence is there? How many miles shorter from north to south
is the Eastern Continent than the Western? Ans. Not far from
900. How many miles more than the Western does it extend in
a due east and west course? Ans. Nearly 3,500.

What three of the grand divisions of land resemble a triangle
in shape? What great island in the north has a similar shape?
What two peninsulas on the south of Asia also present this
shape? How are the two southern grand divisions connected
with the adjoining portions of the continent? What, then, is
their character? Ans. They are, both, vast peninsulas. In what
common direction does the narrowest point of each of the trian-
gular masses before referred to extend? Do most of the penin-
sulas of both of the continents point in the same direction?
Does it appear to be a general rule that the lands widen toward
the north and grow narrower toward the south? Do the castern
and western shores of the great triangular masses, as we advance
northward, diverge nearly alike from a north and south line?

About how much has this

divergence been found to average?

Ans. 2340 from a north and south line, or nearly the same as the inclina-
tion of the earth's axis to a perpendicular to the plane of its orbit. Are
the southern points of the great triangular masses generally ele-
vated and mountainous, or otherwise?

On which side of Africa is there a deep inward bend? Is
there a similar bend on the southwest side of South America?
Of Australia? Of the Peninsula of Hindoostan?

Would you infer from the correspondences referred to in the
last two paragraphs that the forms of the great bodies of land
are merely accidental, or are, in some degree, the result of like
causes operating in accordance with fixed laws?

What two grand divisions are the most regular in outline?
What two abound in large peninsulas, and therefore have ex-
ceedingly varied coasts? Has the eastern or western side of
America the more varied contour, and therefore the longer shore
line?

RELIEFS OF THE CONTINENTS.

Near what tropic is it situated? What mountain-chain on the
Western Continent is the next highest, and near what tropic are
its most elevated parts?

Are the most extensive highland plains or plateaus in the East-
ern or Western Continent? [The student will observe that the high-
lands are colored brown; the lowlands, green.] What grand division
consists chiefly of highlands?

Are the principal lowlands of the earth on the long or short
slopes of the continents? Which continent has the greatest ex-
tent of lowlands in the warm temperate and hot latitudes?
As the lowlands of these latitudes are, generally speaking, the
most productive regions of the earth, may we infer that the
Old, or New, World is best suited to the support of a dense
population?

INSULAR REGIONS.

Between what two oceans do we find the greatest assemblage of large islands on the globe? With what grand division do most of those north of Australia appear to be intimately associated? What, therefore, are they sometimes called? Ans. The Asiatic Archipelago. The middle regions of what great ocean are dotted with an immense number of small islands? Does this vast archipelago appear to be wholly independent of either of the continents? What has its existence here-together with other facts-led many scientific men to conclude? Ans. That it occupies the area of a once unbroken continent which has been gradually submerged, and whose lofty sunmits form the basis of most of the present

On which side of the Western Continent are the principal mountain-chains? Nearest what ocean are they situated, or toward which does the continent present its shortest and most abrupt slope? On which side of the Eastern Continent are the chief mountain-chains? Nearest what two oceans do they lie, or toward which is the short slope of this continent? Around what oceans, then, may it be said the principal mountain-chains of the earth are arranged, and the short slopes of the continent inclined? Which and where is the highest mountain-chain on the globe? insuler grups and chains.

north to south in the latter. land, which extends from east to west in the former, and from

the Gulf of Guinea. vided territory, which some great convulsion separated. peculiar outline, that the two continents once formed an undiMexico, and the convexity of the Brazilian shore is opposite to The idea has been entertained, from this Western Africa is opposite to the indentation of the Gulf of retreating shape of the land. Thus the great convexity of adaptation to unite may be observed in the advancing and with the eastern shores of North and South America, a mutual 34. Comparing the western shores of Europe and Africa

Continent and the Western is in the prevailing direction of the 33. The great point of dissimilarity between the Eastern

LESSON IV.

ISLANDS.

(46,220 square miles). and their relative size, as compared with the area of the State of New York 36. The following table exhibits the area of some of the largest islands,

level of the waves. Its extent of coast-line is about 8,000 miles. to south, and contains an area of about 3,000,000 square miles. lia; it is 2,400 miles from east to west, 1,700 miles from north are mere banks of sand or points of rocks just raised above the nents, with systems of mountains, rivers, and lakes, while others The largest island in the world is Austra35. ISLANDS differ vastly in size, some being miniature conti

archipelagoes, or singly. 38. Islands occur under various conditions, in chains, clusters,

180 from any other land. and is situated 260 miles from the north coast of Ireland, and the North Atlantic; it is only a hundred yards in circumference, 37. Of the small islands, the most remarkable is Rockall, in

ning with Vancouver's Island on the south. On the northwestern coast there is a long chain of them, beginnents. America offers numerous examples of this kind of islands. follow each other in succession along the margin of the contiislands. They are long in proportion to their breadth, and and on this account they are sometimes termed continental 39. The principal chains are adjacent to some main shore, Another range

Britain? Sumatra? Papua, or New Guinea? size as compared with the State of New York? Ireland? Newfoundland? Cuba? Great The largest island and its exten:? 36. What is the area of Iceland, and what its relative and Asia with the eastern shores of North and South America? 35. How do islands differ? ern continents? 84. What may be observed by comparing the western shores of Europe Questions.-33. What is the great point of dissimilarity between the Eastern and WestMadagascar ? Borneo? Australia?

longing to America are mentioned? Other instances? occur? 39. Where are the principal chains? Shape and arrangement? What chains be 37. Give particulars of the island of Rockall. 38. Under what various conditions do islands

occurs at the southern extremity of South America, extending from Chiloe to Cape Horn. To this class also belong the Aleutian Isles, which form a chain between North America and Asia, in the North Pacific, and the Kurile and Japan Isles, stretching along the eastern Asiatic coast.

40. Clusters, sometimes called oceanic islands, are those which occur at a distance from continents. They are very numerous in the Pacific and Indian oceans. They usually contain one or two principal members centrally situated with reference to others of smaller size, as, for example, the Marquesas and Society groups.

41. An archipelago is a sea interspersed with numerous islands. The term archipelago was originally applied to those islands which lie between the shores of Greece and Asia Minor. The principal archipelagoes are the Caribbean, or Antilles, in the West Indies; the Maldive and Laccadive, in the Indian Ocean; the Dangerous, Louisiade, and Great Cyclades, in the Pacific Ocean.

42. Single islands at a great distance from any other shore are of rare occurrence. St. Helena, remarkable for being the

ST. HELENA.

place of Napoleon's last exile, is 1,800 miles from the coast of Brazil, 1,200 from the coast of Africa, and 680 from Ascension Island, the nearest point of land. Ascension Island is also 520 miles from its next neighbor, the Isle of St. Matthew.

43. A vast number of islands are volcanic. Some are at present the scenes of fiery convulsions. Volcanic islands are found principally in the Indian and Pacific oceans, though some occur in high northern and southern latitudes. They are characterized by a considerable elevation, with a precipitous

coast.

44. In the Grecian Archipelago, the Old Kaimeni, a small islet, was thrown up somewhat more than two centuries before the Christian era. A second appeared the year 1573, called the Little Kaimeni, and a third was formed in the year 1707, called the New Kaimeni.

45. In the year 1811, the temporary island of Sabrina rose off the coast of St. Michael, one of the Azores. It attained the height of 300 feet, was about a mile in circumference, but gradually subsided, and wholly disappeared by the close of February, 1812. In 1813 there were five hundred feet of water at the spot.

Questions.-40. What are clusters? Where numerous? How usually arranged? Examples? 41. What is an archipelago? How originally applied? Principal archipelagoes? 42. What is said of single islands? St. Helena? Ascension Island? 43. What is said of volcanic islands? Where principally found? How characterized? 44. What volcanic islands were formed in the Grecian Archipelago? 45. Give the particulars of the formasion and disappearance of the island of Sabrina. 46. Of Graham Island. 47. Islands and reefs in the Indian and Pacific oceans? To what owing?

LESSON V.

CORAL ISLANDS.

47. A VAST number of islands and reefs* in the Pacific and Indian oceans are of coral formation. They owe their existence to the work of countless myriads of the coral-polyps, which inhabit those seas, and which flourish only in the warmer regions of the globe.

48. Coralline structures are sometimes of enormous extent. On the northeast coast of Australia is a reef of coral called the Great Barrier Reef, having a length of nearly 1,000 miles, and being in one part unbroken for a distance of 350 miles. Some groups of coral islands in the Pacific are from 1,100 to 1,200 miles in length, by 300 or 400 in breadth, as the Dangerous and Radack archipelagoes, for example. The Maldive Islands, situated in the Indian Ocean, forming a chain of 470 geographical miles, are composed throughout of a series of circular assemblages of islets, all formed of coral.

49. The following description of coral animals and their operations is from Hughes' "Manual of Geography:" "The coral reefs of the Pacific, as well as those in other parts of the globe, are all produced by the secretions of the coral insect, and the process by which they are formed is one of the most The architects of these wonderful structures are polyps of minute size, and of curious and instructive phenomena which the natural world presents to view. various species, but all possessing a general similarity of form and structure. They consist, to appearance, of a little oblong bag of jelly, closed at one end, but having the other extremity open, and surrounded by tentacles (usually six or eight in number), set like the rays of a star.

50. "Multitudes of these tiny creatures are associated in the secretion of a common stony skeleton, that is, the coral, or madrepore, in the minute orifices of which they reside, protruding their mouths and tentacles when under the water; but the moment they are molested, or become exposed to the atmosphere, withdrawing by sudden contraction into their holes. It is proved by observation that these creatures are unable to exist at a greater depth than twenty or thirty fathoms; so that the numberless coral islands of the Pacific, and other seas, must be based upon submarine rocks or mountains, though it was at one time supposed that they were raised, by the process described above, from the bottom of the sea."

Questions.-48. Extent of coralline structures? Great Barrier Reef? Groups in the Indian and Pacific oceans? Examples? Maldive Islands? 49. Coral reefs, how formed? Architects of these wonderful structures? Of what do they consist? 50 Describe the operations of the coral insects. To what depth do they exist? Upon what must coral islands be based?

* REEF, a chain or range of rocks lying at or near the surface of the water.

51. Coral formations are of four different kinds, namely, atolls, or lagoon islands, encircling reefs, barrier-reefs, and coral fringes.

52. An atoll consists of a circular strip or ring of coral surrounding a shallow lake or lagoon in its center. The circular reefs just raise themselves above the level of the sea, with an average breadth of a quarter of a mile, oftener less, and are surrounded by a deep and often unfathomable ocean. annexed cut represents one of these circular islands inclosing a lagoon of tranquil water.

CORAL ISLAND.

The

The usual form of such islands may be seen in the section below.

a

b

SECTION OF A CORAL ISLAND.

a, a, habitable part of the island, consisting of a strip of coral, inclosing a lagoon. b, b, the lagoon.

53. Lagoons are found in a very large proportion of the coral islands. They were found in twenty-nine out of the thirty-two islands visited by Beechey in his voyage to the Pacific. The largest was thirty miles in diameter, and the smallest less than a mile. There is almost always a deep narrow passage opening into the lagoon, generally on the leeward side, which is kept open by the efflux of the sea, as the tide goes down, and through this channel ships may sail into the inclosed waters and find a good harbor.

54. Encircling-reefs are those which extend around mountainous islands, commonly at a distance of two or three miles from the shore, rising on the outside from a very deep ocean, and separated from the land by a channel 200 or 300 feet deep. The Caroline Archipelago exhibits examples of this structure. Otaheite (Tahiti), the largest of the Society group, is an instance of an encircled island of the most beautiful kind, being hemmed in from the ocean by a coral band, at a distance varying from half a mile to three miles.

55. Barrier-reefs are similar in their structure to the two preceding classes, but differ from them in their position with regard to the land. The largest of this class is the Great Barrier Reef off the northeast coast of Australia, before alluded to (48). It rises up in the ocean at an average distance of from

Questions.-51. Kinds of coral formations? 52. The atoll? What does it surround? Height of the circular reef? Breadth? How surrounded? 53. Lagoons? Lagoons found by Beechey? Their extent? Openings into lagoons? 54. Encircling-reefs? Example? Otaheite? 55. Barrier-reefs? The largest of this class?

20 to 30 miles from the shore, and extends to the distance of about 1,000 miles.

56. The action of the waves as they dash upon this reef has been admirably described: "The long ocean-swell being suddenly impeded by this barrier, lifted itself in one great continuous ridge of deep blue water, which, curling over, fell on the edge of the reef in an unbroken cataract of dazzling white foam. Each line of breaker ran often one or two miles in length with not a perceptible gap in its continuity. There was a simple grandeur and display of power and beauty in this scene that rose even to sublimity. The unbroken roar of the surf, with its regular pulsation of thunder, as each succeeding swell fell first on the outer edge of the reef, was almost deafening, yet so deep-toned as not to interfere with the slightest nearer and sharper sound. But the sound and sight were such as to impress the spectator with the consciousness of standing in the presence of an overwhelming majesty and power."

57. The Florida reefs are of this class. By examining a map of the waters south of Florida, it will be seen that they are studded with a range of islands called the Florida Keys. These keys rise but a few feet, perhaps from six to eight or ten, or at the utmost to twelve or thirteen feet above the level of the sea. They begin to the north of Cape Florida, and extend in a southwesterly direction, gradually receding from the land until opposite Cape Sable. Farther to the west they project in a more westerly course as far as the Tortugas Islands, which form the most western group: Most of these islands are small, the largest of them, such as Key West and Key Largo, not exceeding ten or fifteen miles in length; others only two or three, and many scarcely a mile. Their width varies from a quarter to a third or half of a mile, the largest barely measuring a mile

LESSON VI.

59. The great danger of this reef arises from the fact that throughout its whole range it does not reach the surface of the sea, except in a few points, where it comes almost to the level of low-water mark. It therefore presents a range of most dangerous shoal grounds, upon which thousands of vessels, as well as millions of property, have been wrecked.

60. Coral-fringes are those formations which extend along the margin of a shore, and have no lagoons.

61. Captain Basil Hall, in his "Voyage to Loo-Choo," makes the following observations on coral islands: "The examination of a coral reef during the different stages of one tide is particularly interesting. When the sea has left it for some time, it becomes dry, and appears to be a compact rock exceedingly hard and ragged; but no sooner does the tide rise, again, and the waves begin to wash over it, than millions of coral worms protrude themselves from holes on the surface which were before quite invisible. These animals are of a great variety of shapes and sizes, and in such prodigious numbers, that in a short time the whole surface of the rock appears to be alive and in motion.

62. "The most common of the worms at Loo-Choo (an island in the Pacific east of China), was in the form of a star, with arms from four to six inches long, which it moved about with a rapid motion in all directions, probably in search of food. Others were so sluggish that they were often mistaken for pieces of the rock; these were generally of a dark color, and from four to five inches long and two or three round. When the rock was broken from a spot near the level of high water, it was found to be a hard, solid stone; but if any part of it were detached at a level to which the tide reached every day, it was discovered to be full of worms, all of different lengths and colors, some being as fine as thread and several feet long, generally of a very bright yellow, and sometimes of a blue color; while others resembled snails, and some were not unlike lobsters and prawns in shape, but not above two inches long.

63. "The growth of coral ceases when the worm which creates it is no longer exposed to the washing of the tide. Thus a reef rises in the form of a gigantic cauliflower, till its top has gained the level of the highest tides, above which the worm has no power to carry its operations, and the reef, consequently, no longer extends itself upward. The surrounding parts, however, advance in succession till they reach the surface, where they also must stop. Thus, as the level of the highest tide is the eventual limit to every part of the reef, a horizontal field comes to be formed coincident with that plane, and perpendicular on all sides. The reef, however, continually increases, and being prevented from going higher, must extend itself laterally in all directions; and this growth being probably as rapid at the upper edge as it is lower down, the steepness of the face of the reef is preserved; and it is this circumstance which renders this species of rock so dangerous to navigation. In the first place, they are seldom seen above the water; and in the next, their sides are so abrupt that a ship's bows may strike against the rock before any change of soundings indicates the approach of danger.

64. "For a long time it was supposed that the coral formations were raised from the floor of the fathomless ocean by the unaided efforts of these little creatures, but more accurate observations have proved that the animals cease to live at a greater depth than twenty or thirty fathoms. ... As some of these islands are elevated 200 and 300 feet above the sea-level, it is evident that they must have been raised by submarine forces; in short, that the volcano and the earthquake must have been employed in rearing them to their present elevation. Mr. Darwin has traced those regions throughout the Pacific, in which upheaval and depression alternately prevail. Thus a band of atolls and encircled islands, including the Dangerous and Society archipelagoes, constitutes an area of subsidence more than 4,000 miles long and 600 broad. To the westward, the thain of fringing-reefs, embracing the islands of the New Hebrides, Solomon, and New Ireland, form an area of elevated coral. Farther westward, another area of subsidence is met with, including the islands of New Caledonia, and the Australian barrier."

Questions.-59. Danger of this reef? Vessels and property destroyed? 60. Coralfringes? 65. What are mountains? What is said of their heights? Uses of mountains? 66. Insulated mountains? Examples? What is the usual arrangement of mountains? To what is the term system applied?

CLIMBING THE ALPS.

MOUNTAINS.

65. MOUNTAINS are the most considerable elevations of the surface of the earth. They are of various heights, the loftiest having an elevation of more than five miles above the level of the sea. Though generally sterile, and unsuited for the residence of man, they have their uses in the economy of nature. They accumulate the moisture of the clouds, and feed the rivers which water and fertilize the plains below. They increase the surface of the earth, and consequently its productions. To their gigantic proportions, their lofty projections, and their broken and varied forms, are we largely indebted for sublime and savage, or beautiful and picturesque scenery.

66. There are but few insulated mountains, or mountains remote from other masses, and ascending abruptly from a level country. The examples are chiefly volcanic, as Mount Egmont, in New Zealand, and the Peak of Teneriffe, on one of the Canary Islands. The usual arrangement is in groups or chains, the members of which are connected at the base. The term system is applied to a series of chains, groups, and parallel ranges lying in the same general direction, though detached. The highest points are usually about the middle of the range.

67. The great mountain systems of the two continents follow the prevailing direction of the land in each; those of the Western World running north and south; those of the Eastern, cast and west. The course of secondary chains, as the Apennines in Italy, the Dovre-field in Norway, and the Ghauts in India, corresponds with the greatest length of those peninsulas.

68. The highest known mountain on the globe is Mount Everest or Gahoorishanka, in Asia. It belongs to the Himalaya range, and is situated in about longitude 86° 50' east. Its summit is 29,002 feet above the level of the sea. In the same range, to the east, is Kunchinjinga, the next in height (28,178 feet), and which was, until recently, considered the highest

Questions.-67. Direction of the great mountain systems of the two continents? Course of the secondary chains? 68. The highest known mountain, its situation and height? Kunchinjinga? Name and height of the loftiest mountain in South America? In North America? In Africa? In Europe?

mountain on the globe. According to recent statements the loftiest mountains known in the other four grand divisions are, in South America, Tupungato, one of the Chilean Andes (22,450 feet); in North America, Popocatapetl, in the volcanic chain of southern Mexico (17,884 feet); in Africa, Mount Kenia (supposed about 20,000 feet); in Europe, Mount Blanc (15,760 feet).

69. The mountains of the torrid zone are capable of being inhabited by man to a very considerable height. Under the equator the line of perpetual

snow is not less than about 16,000 feet above the level of

the sea. As we approach toward the poles this line gradually descends, rendering the mountains of the temperate zones inhabitable to no very considerable elevation. On Mount Blanc the snow-line is about 8,500 feet above the

MOUNT CHIMBORAZO.

sea-level, and at the height of 6,000 feet the climate is of very great severity.

70. Table of the heights above the sea of some remarkable inhabited sites.

M. Boussingault and Colonel Hall....

LESSON VII.

1831..19,699

THE MOUNTAIN SYSTEMS OF THE WESTERN CONTINENT. 73. NORTH AMERICAN MOUNTAINS.-North America contains three great mountain systems,-the Rocky Mountains, the mountains of the West Coast, and the Apalachian system. It embraces besides, the elevated regions of the Ozark Mountains, the highlands of Labrador and the Arctic coast, and the mountain traversed plateaus of Mexico and Central America. 74. The Rocky Mountains constitute the most extensive mountain system of North America. They

extend from north to

south through all the

9,272

wider parts of the con

Quito, capital of Equador

Ladak, city, Little Tibet.

9,540 9,995

tinent; or from the shores of the Arctic

4,300

Cuzco, ancient capital of Peru. 11,380 La Paz, city, Bolivia...

Ocean on the north

.12,226

Puno, city, Peru..

.12,870

on

6,453

Villages on south side of the
Himalayas.
Potosi, Bolivia, highest city of
the globe..
Antisana, shepherds' huts,
Equador...

.13,000

.13,350

ed house of Prussia Splugen, village, Switzerland.. 4,711 Mont Louis, Eastern Pyrenees, highest town of France.. 5,171 6,380 Cabool, Afghanistan.... Post-house Mont Cenis, Alps... Soglio, village in the Grisons,

highest village in Europe... 6,714 Hospital of St. Gothard, Alps.. 6,808 Mexico, city.

Arequipa, city, Peru

13,354 .13,690 Tacora, village, Peru.. 7,570 Rumihausi, post-house, Peru. .15,540 ..15,724 7,852 Ancomarca,

66

71. The summits of the loftiest mountains have never been reached, though some adventurous travelers have attained The difficulties heights where man can find no local habitation. encountered in ascending elevated mountains arise from the precipitous character of the surface, the vast accumulation of snow, the intense cold, and the rarity or thinness of the atmosphere. Travelers have found the rarefied atmosphere on high mountains to cause a bleeding from the nose and eyes, and to produce other unpleasant effects.

72. In the following list are given some remarkable heights which have been reached :

Questions.-69. Habitation of mountains in the torrid zone? The line of perpetual snow under the equator? Toward the poles? 70. Height of Geneva? Madrid? Jerusalem ? Great Salt Lake City? Mexico? Santa Fé de Bogota? Chuquisaca? Quito? Potosi ? 71. What is said of Shepherds' huts, Equador? The post-house, Rumihausi, Peru? heights attained by adventurous travelers? The difficulty of ascending elevated mountains? 72. Name the heights reached on the following mountains, and by whom: Mount Blanc, Jungfrau, Ortler Spitz, Peak of Demavend, Ararat, Pamir, Peter Botte, MounaKach, Mount Egmont, Silla de Caraccas, Pichincha, Chimborazo.

ROCKY MOUNTAIN SCENERY.

to about the parallel of 32° on the south. The northern portion is divided into numerous ranges, with hardly more elevation than from one to two thousand feet. As they advance southward their height increases, and many of their summits rise above the snow-line. They attain the most considerable elevations between the 55th and 38th parallels. The average heights between these limits is from seven to eight thousand feet. The highest known summits of the system are Mount Brown (15,690 feet) and Mount Hooker (15,700 feet), both near the line of the 52d parallel.

75. Numerous passes occur in the range of the Rocky Mountains, the most noted of which is that known as the South Pass, near the 41st parallel. It is at an altitude of more than 7,000 feet above the level of the sea, and affords a passage so easy of access that a wagon drawn by horses might travel through it. Thousands of emigrants, with their cattle, every year traverse this pass on their way to the valleys of the Pacific.

76. The Mountains of the West Coast extend along the Pacific, from Cape St. Lucas to the Peninsula of Alaska. They Questio s.-73. What three great mountain systems does North America contain? What other elevated regions dos it embrace? 74. What is said of the Rocky MountWhere do ains? Where do they extend? What is said of the northern portion? they attain the most considerable elevation? What is the average height between these limits? Which are the highest summits of the system? 75. Where is the principal pass situated? What is said of it? 76. Where do the mountains of the West Coast extend? What minor ranges do they embrace? What peaks, their height and situation? What is said of the Sierra Nevada? Where do the gold regions of California lie?