degrees of latitude are marked; and on the top and bottom, the degrees of longitude are marked. When the meridians and parallels of latitude of a place are wanted, a parallel line of latitude must be drawn through it, by the same rules the other parallels are drawn, and it cuts the sides at the degree of latitude of the place: and to find the longitude of the place, draw a circle of longitude through it, by the same rules as the other circles are drawn, and it cuts the top and bottom at the degree of longitude of the place.

the heads of arrows pointing to the coasts toward which the wind blows. Small rivers are described by a single crooked waving line, and large rivers by such double and treble lines made strong and black. Bridges are distinguished by a double line across the river.

GENERAL GEOGRAPHY.

PART II-PHYSICAL GEOGRAPHY.

To describe the earth as a natural body, such as it came forth from the ALL-PERFECT HAND,' and the relations subsisting between it and the organic beings which inhabit its surface, without reference to any changes which the art of man may have effected upon it, is the province of Physical Geography, a science which, as all its facts can only be ascertained by the united observation of successive ages, has not yet been perfected, or reduced into a complete systematic form. The physical geographer considers the earth as a whole; he directs his researches to its principal features and phenomena,-to its various productions in respect of situation, to the physical changes which have been wrought upon its surface, and finally, examines those great general conclusions respecting its formation and history which these researches suggest. It is, however, to be observed, that we are acquainted with the external crust only of the earth and the surrounding atmosphere; for by the deepest artificial excavations which have yet been made, we have not approached nearer to the centre of the earth than 7 part of the semidiameter, or perhaps not so much as T000 part, if we make allowance for the height of some of the deepest mines above the level of the sea, which is the true surface-line of the earth. The interior of our globe, therefore, is wholly unknown to us; and philosophers must confine their speculations regarding it to very doubtful analogical reasonings. We shall in this essay treat, 1st, of the land; 2d, of the sea; 3d, of the atmosphere; 4th, of the productions of the globe; 5th, of the various changes which have taken place on its surface; and, lastly, of the general conclusions deducible from the facts thus brought together.

CHAP. I.-OF THE LAND.

General View.] THE total superficies of the globe is usually estimated at about 200,000,000 British square miles, and the natural division of this surface is into earth and water: about seven-tenths of the whole being occupied by the ocean, and the remaining three-tenths consisting of land, elevated above the level of the sea, unequally distributed, and interspersed with smaller collections of water, at various heights, and, in a few instances, somewhat lower than the general surface of the ocean. The terrestrial surface consists of two continuous spaces of land, of vast extent, distinguished by the name of the Old and New Continent; and a multitude of smaller detached portions called islands. It deserves attention, that while the general direction of the land in the two continents is entirely different, the direction of the large peninsulas, or those parts of a continent which run out into the sea, is similar; and that these peninsulas uniformly terminate in a high rocky promontory, having a bay on the west, and an

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island or cluster of islands on the east side. Thus Cape Comorin has the Arabian Gulf on the W. and the island of Ceylon on the E. Africa terminates in the Cape of Good Hope, and has on the W. the large Gulf of Guinea, and on the E. the extensive island of Madagascar. The western coast of America, from the Straits of Magellan to the Tropic of Capricorn, forms one great basin, and on the E. are the Falkland and Sandwich Islands. New Holland, which in point of extent may almost be regarded as a third continent, has on the S.W. a gulf of considerable depth, and on the E. the Island of New Zealand. Even Europe exhibits a similar configuration; the point of land which forms one part of the Strait of Gibraltar, has the Gulf of Seville on the W., and on the E. the group of the Spanish islands. The only exceptions to this remark, are the peninsula of Yucatan, in Mexico, and that of Jutland, in Denmark, both of which are directed towards the north, while all the rest point south. The first feature which strikes our attention in surveying the land-surface of our globe is the inequalities and diversities of appearance which it presents. There are very few perfect planes upon earth: the greater number, perhaps all of them, have a more or less perceptible inclination; and those countries which we describe in general terms as flat, have in reality an undulated surface. The lowest districts of a country are most commonly its shores. The land rises gradually from the beach, and usually attains its highest elevation in the interior or central parts of the country. Indeed every island, and even the continents themselves, may be considered as composed of one vast mountain, having its roots fixed in the bowels of the earth, its lower regions covered by the waves of the ocean, and its upper parts divided into all those inequalities of surface which land-scenery everywhere presents. distribution of water and land is very unequal: if we compare the northern and southern hemispheres as divided by the equator, we shall find that, supposing the quantity of land in the northern hemisphere to be represented by 16, the quantity in the southern will be scarcely equal to 5. Buffon and some other philosophers, therefore, asserted that a great continent must exist towards the south pole, in order to counterbalance the mass of land in the northern hemisphere; but the high southern latitudes have as yet been found to contain only a few islands. However, this fact does not prove that there is a less mass or weight of land in the southern than in the northern hemisphere; for it is possible that the land may be only rather more depressed in the south, and consequently covered by the sea.

The

Mountains.] The most considerable elevations of the earth's surface are called mountains. Hills are distinguished from mountains by their smaller size. A series of mountains or hills, connected together by one continuous base, such as the Andes, is called a chain. A collection of these chains is called a system. Thus we say the system of the Alps, the Julian chain. Mountains present a variety of external forms. Their general shape is conical; that is, they diminish gradually, into a more or less pointed summit. But this ordinary outline assumes various modifications, especially in very high mountains, which sometimes shoot into the form of enormous crystals, or appear crowned with a vast and rocky battlement, or present a highly fantastic outline of naked rocks, heaped and crowded upon each other in every position. These appearances are called needles, peaks, teeth, domes, forks, horns, &c. according to their supposed resemblances; and this

difference of outline is thought by some geologists to indicate a difference also of internal structure and composition. When a mountain rises into two ridges at the summit, with a circular hollow between them, it is said to have a saddle-ridge. When the highest ridge is divided into a number of distinct teeth, it is called a serrated-ridge. The deep rugged excavations formed in the sides of mountains by the descent of streams are called ravines; and the extensive hollows which occur between chains of mountains are denominated vallies. Mountains which rise from the plain at an angle below 45°, are considered as having a gentle inclination; in proportion as the angle exceeds 45°, the ascent is said to be steep. The greater number of mountains have one of their sides very steep, while the other presents a gradual slope. Thus the Pyrenees are steeper towards the south than the north; and the Alps on the side of Italy than that of Switzerland. The cause of this configuration is very obvious, when we reflect that chains of mountains are frequently nothing more than the abrupt borders of highland plains or plateaus, obliquely inclined to a lower terrace. And hence with most of the chains of the globe their steepest side is that which approaches to the sea. Thus the Himalaya mountains are steepest on the S.W. sides, which front the Indian plains; and the Elboors are steepest towards the Caspian sea. In general also, mountains that surround lakes or basins present their steepest sides to the water.

A

Connexion of Chains.] A greater or less connexion may always be traced between the chains of mountains in the same country; nay, some connexion may perhaps subsist between the whole mountain-systems of our globe. Thus the Uralian mountains which divide Asia from Europe, and direct one branch towards the White Sea and Nova Zembla, seem connected with the ridge which divides Norway and Sweden from Russia. Another chain stretches out from Northern India to Thibet and Cashmere-where it forms the most elevated region of the whole earth and runs towards the west through Persia, and eastwards through China. From the highest land of Northern Asia, at the mountains of Bogdo, which separate the Calmucs from the Monguls, runs another chain, under the name of Massart, southward to Thibet. Another goes towards the west, under the name of Alak, through the steppes of Independent Tartary and Bucharia, and joins the Uralian mountains. third branch of the Bogdo, called Zangai, runs eastward through Mongolia and Chinese Tartary, and forms the Corea and the cliffs and islands of Japan. A fourth branch is the Altai mountains, which bound Siberia from the Irtysh to the Amoor. Between the Caspian and the Black Sea lie the Caucasian mountains. The probable connexion of this with one of the preceding chains has not yet been traced; but it sends branches through Asia Minor to Arabia, which form the Taurus, Mount Sinai, and Lebanon. Another branch goes round the Black Sea towards Macedonia, where it diverges into a number of chains. The Carpathian mountains stretch from the Black Sea, between Moldavia, Wallachia, and Transylvania, through Poland and Silesia, and connect themselves with the German mountains. The Sudetic chain runs through Austria, between Bohemia and Silesia, and sends some branches N.E. through the Saxon Erzgeburge and the Voigtland. The Alps are connected with the neighbouring chairs of Germany, Italy, and France; and the Appenines probably extend under the sea towards the mountains of Africa, where the Larger Atlas may be connected with the Arabian

chain. Secondary chains run along the banks of the Nile, through Upper Egypt, Nubia, and Abyssinia, into the unknown countries of the interior, where they are probably connected with the Mountains of the Moon, whence chains may stretch into Southern Africa towards the mountains of the Cape. With the South American Cordilleras a few secondary chains are connected; and one chain proceeds northward, through the isthmus of Panama, into North America, where it runs along the western coast, and sends several branches into the interior. Future travellers may perhaps ascertain that this chain is connected with the mountains of Asia in the highest north.

Insulated Mountains.] Some mountains are completely insulated, that is, are quite remote from any chain or group, more particularly those of a volcanic origin. The rock of Gibraltar, and the fortress of Gwalior, in Hindostan, are of this description. Sometimes we find these solitary masses exhibiting only an abrupt naked rock; others are covered with beautiful verdure, and slope gently down to the plains.

Economy of Mountains.] Many authors have regarded mountains as imperfections in the frame of the terrestrial globe, and one of the consequences of that fearful breaking-up of the structure of the globe which took place at the period of the deluge. But this opinion seems wholly fanciful. The eternal hills form as it were a frame-work for the security and consolidation of the softer parts of the earth, which might otherwise be swept away by the fury of the winds and waters. They are the reservoirs of rivers, and the storehouses of the richest minerals; they increase the surface, and consequently the products of the earth; and give diversity and richness to natural scenery. Wolfius thinks that mountains preserve the earth's equilibrium, and the uniformity of its motions; and we know that in many instances they have furnished heroic nations with the means of repelling foreign invasion.

Classes of Mountains.] The most general and natural division of earthy bodies is founded upon the substances of which they are composed. The earths are of various kinds, colours, and qualities. The most widely diffused earth, and in fact the basis of the whole frame of the globe is stone of different species. The strata of mould with which the great bed of stone is covered, consists of stones crumbled to powder by the action of the atmosphere, and the elementary remains of plants and animals which have perished upon its surface. The natural fertility of a country depends upon the extent to which this species of soil is found in it. The various species of stone are not thrown together without any principle of order and connexion; they are found occupying certain distinct and relative situations, in which they compose what are called strata. Werner, the celebrated founder of the German school of mineralogy, of which the principal geologists in Europe are disciples, first explained the laws of stratification and determined the rules by which the relative age of minerals might be fixed, and their various species traced through all the successive changes which they have undergone. Daubisson, Dolomieu, Spallanzani, Breislack, Cordier, Ramond, Cuvier, Hutton, Playfair, Jameson, Macculloch, Humboldt, Steffens, Leopold Von Buch, and Von Baumer, have since distinguished themselves in this path of science, and have advanced various new and occasionally conflicting views.

Primitive Rocks.] The appearance presented by the mountains and solid parts of the earth's surface, irresistibly leads us to the conclusion,