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opposite quarter gradually disappear; which coulJ not happen if the earth were a plnne in tbat direction, like the longitudinal surface of a cylinder: for, in this case, we should see all the stars of the heavens, from the North pole to the South, on whatever portion of the cylindrical surface we were supposed to be placed. This might be illustrated by surrounding a terrestrial globe, or any other ball, with a large hoop or circle, about twice or thrice the diameter of the globe, on which some of the stars might be represented. This circle might be made either of wood or pasteboard, and the globe within it connected with a moveable plane to represent the horizon, as exhihited in the following figure.
In this figure, the inner circle represents the earth; A, the North pole, and B, the South; and the larger circle, E C F D, a portion of the celestial sphere. It is evident, that if a person be placed at the equator at G, he will see all the stars above the horizon C D, in the hemisphere D F C. If he move to the point H, 45 degrees nearer to the North pole, the moveable plane C D, may be moved in the direction E F, to represent the horizon of that place, when it will evidently appear that he has now lost sight of all the stars situated between F and D, and that the polestar C, which, in his former position, was in his horizon, is now elevated 45 degrees above it. In a similar manner it might be shown that no such difference in the aspect of the starry heavens could take place, in travelling from South to North, or from North to South, were the earth of the form of a cylinder; and consequently, that the fact above stated proves the rotundity of the earth in that direction.
That the earth, considered as a whole, notwithstanding the irregularities caused by its mountains and vales, is of the figure of a sphere, may be illustrated from the phenomenon exhihited during the progress of an eclipse of the moon. An explanation of a lunar eclipse, accompanied with familiar illustrations, will be requisite to be given, before the proof of the globular figure of the earth be
deduced from this phenomenon. Let the flame of a candle or gas-lamp represent thr sun, and a wooden ball, supported by a wire represent the earth; and let a circle, somewhat less than the diameter of the ball, be drawn on a piece of pastebonrd, and coloured, to represent the moon. Let them be placed at a moderate distance from each other, and nearly in a straight line, and let the pupils mark the curve of the shadow of the ball on the circle representing the moon, and that there is no body but one of the figure of a globe that can project a circuhr thndotit in every direction; for, although a counter or a shilling will cast a circular shadow in o, e direction, yet in every other direction it is either an oval or a straight line. Hence the conclusion is easily deduced, that, if the shadow of the earth falling on the moon is the cause of an eclipse of that orb, and if this shadow, so far as it is seen, is always a portion of a circle, the earth, as a whole, must be nearly of a globular figure. In order to render such explanations clear and impressive—when a visible eclipse of the moon takes place, young persons should be directed to observe each a pnenomenon with attention—to mark the figure of the earth's shadow when it first enters on the eastern margin of the moon— before it leaves its western edge!—and during the whole of its progress along the disk, if it happen to be a partial eclipse of the moon; and, although they be not directly engaged in geographical studies at the time, yet sucb observations will afterwards prepare them for understanding such explanations as now suggested. Such minute illustrations, so far from being superfluous or unnecessary, are essentially requisite for producing in the minds of *he young, a rational conviction of the rotundity of the earth. I have known young ladies, and gentlemen too, who had passed through a scholastic course of geography, and yet could assign no other reason for their believing that the earth is globular, than this, "That their teacher told them so, and showed them a representation of it by the artificial globe." Besides, such specific explanations and illustrations tend to exercise the reasoning powers of the young, and to bring to their view a variety of incidental facts and circumstances connected with the subject, and thus their store of general information is gradually increased.
Having, by such methods as the above, produced a clear conviction of the spherical form of the earth, the next step might be to convey an impressive idea of its magnitude. For this purpose, let a class of young persons be conducted to an eminence, where they murht have a distinct view of a landscape stretehing nbont eight milct irr every directi an. Let their attenBon be particularly directed to the various objects which compose the scene before them; let them be directed to consider the vast mass of materials contained in the hills or mountains which form a portion of the view—the millions of labourers, and the number of years which it would be requisite to reduce the whole landscape to a perfect level,—the number of trees and shrubs of every kind contained within the range of their view—the almost innumerable millions of flowers of every hue, stalks of corn, blades of grass, mosses almost invisible to the naked eye, and vegetables of every description, which cover every portion of the landscape—the cattle, sheep, horses, dogs, and other quadrupeds, and the multitudes of birds, worms, flying and creeping insects, and microscopic animalcule, which no man can number, comprehended within the limits of their view—the number of houses and human beings in the towns, villages, and hamlets, which are scattered around, and the labours in which they are employed—the mass of waters in the rivers, and in that portion of the ocean which lies before them, (if such objects be in view,) and the numerous tribes of fishes which glide through the watery clement Let them be directed to consider the time and exertions which would be requisite to travel to the most distant parts of the landscape, to go quite round it, and to cross it in forty or filly directions, so as to attain a more intimate inspection of the multifarious scenes wid objects of which it is composed. Let certain general calculations be mado of the number and magnitude of such objects, of the mo! ion of the inanimate parts of nature, of the activities of animated beings, and of the quantity of matter which appears on every hand. Having impressed upon their minds, as clearly as possible, such ideas of the rwigniiuile and varitty of the scene before them, let them be informed that the landscape they are contemplating is about 50 miles in circumference, and that its surface contains 200 square miles; but, that the whole surface of the earth contains more than 196 millions of square miles, and, consequently, is nine hundred and eighty thousand times larger than all the objects they behold around them; so that they must conceive 980,000 landscapes aa large as the one before them, before they can form an adequate idea of the magnitude of the earth. To impress this idea more deeply, they may likewise be told, that, were they to remain in the station they now occupy, ten hours every day, (the time usually allotted for daily labour,) and were a landscape of similar client to that which they behold, to pass before their view every hour, till the whole extent and scenery of the terraqueous globe were broolght under their observation,
it would require more than two hundred and sixty-eight years, before they could survey, even in this rapid and imperfect manner, the whole superficial dimensions and variegated scenery of the globe on which we dwell.
Their attention should likewise be directed to the solidity of the earth—that it is not a mere superficies, but contains within its bowels an immense and indescribable mass of matter, extending nearly 7900 or 8000 miles in every direction between the opposite portions of its circumference, amounting to more than 263 thousand millions of cubical miles. An idea of this enormous mass of materials may be communicated by such illustrations as the following:—Suppose Mount Etna,—which ranks among the largest insulated mountains on the globe, and which contains around its sides 77 cities, towns, and villages, and 115,000 inhabitants,—to be 120 miles in circumference around the base, about 10 miles in circumference near the top, and 2 miles in perpendicular altitude, and considering its figure to be nearly that of the frustrum of a cone, it will contain about 833 cubica. miles, which is only the Jtt'ttit'tjt P31' of the solidity of the globe, reckoning it to contain 263,858,149,120 cubical miles; so that it would require more than three hundred milliimi of mountains, such as Etna, to form a mass equal to that of the terraqueous globe: and were theso mountains placed side by side in a straight line, they would extend 12,100,097,574, or more than twelve thousand millions of miles; that is, more than six timet the distance of Herschel, the remotest planet of our system. And were we to travel without intermission, till we reached the extremity of such a line of mountains, at the rate of 25 miles every hour, (tho utmost speed which our steamcarriages have yet attained,) it would require fifty-five thousand, /iro hundred and fifty-one years, before the journey could be accomplished. And, were they arranged in circles, equal to the perimeter of the sun, they would go 4376 times round the circumference of that stupendous globe, and cover a great portion of its surface. Again, suppose that all the inhabitants of the earth were to lie cmployed in removing a mass of materials equal to that of our globe; suppose all that are capable of labouring to be 200 millions, and that each person removes ten cubical yards in a day, it would require more than 1,970,956,164, or, one thousand nine hundred and seventy millions, nine hundred and fifty-six thousand, one hundred and sixty-four years, before such an operation could be completed; which is more than 337,550 times the number of years which have elapsed since the Mosaic creation.
It is of some importance, that, by such I 2 (101)
illustrations, we endeavour to convey to the minds of the young a luminous and inifircitive idea of the magnitude of the globe on which we dwell. For it is the only standard, or scale of magnitude, by which we are enabled to form a conception of the bulk of the ran, and some of the more magnificent globes of the solar system, and of the immensity of the universe. If we entertain imperfect and contracted conceptions of the size of our globe, we shall be led to entertain similar contracted views of the celestial orbs, and of the amplitudes of creation. No adequate conception of the magnitude of our world can be conveyed to the young, by merely telling them that it is 8000 miles in diameter, and 25,000 in circumference, and showing them its figure and the divisions on its surface by an artificial globe. For, in the first place, few of them have an accurate conception of the extent of one thousand miles, much less of twenty-five thousand ; and, in the next place, they are apt to fix their attention merely on the length of a line' or a circle, without 'considering the extent of surface contained in a globe of the above dimensions; and therefore, the number of square miles comprised in the superficies of the earth, amounting to nearly 200 millions, should always be specified, as that which conveys the most correct idea of the amplitude of our globe—and, in the last place, unless an ample prospect be presented to their view, and their attention fixed upon its multifarious objects, while such instructions are imparting, the illustrations of the magnitude of the earth will neither bo clear nor impressive. In a private apartment, where the view is confined to the walls of the room, such instructions would lose a considerable part of their effect
Having thus impressed on the understandings of the pupils clear conceptions of the figure and magnitude of the earth, its leading divisions and grand natural outline* should next be presented to view. An cighteen-inch terrestrial globe should be placed before them, on which they should be directed to mark the great divisions of land and water—that the regions inhabited by man, and other terrestrial animals, lie between two expansive masses of water more than ten thousand miles in length, and one of them nearly the same in breadth, which cover about threefourths of the surface of the globe—that the northern and southern portions of this watery mass are, for the most part, compacted into a body of solid ice; that the other portions move backwards ond forwards in different directions by a kind of libratory motion, every 12 J hours, producing the flux and reflux of the sea; that currents, such as the gxdf strenm, are found in different parts of the ocean, flowing uniformly
in the same direction—that the land is divided into three principal portions or masses, tho Eastern and Western continents, and the territory of New Holland, besides thousands of islands of every form and size, which diversify the surface of the ocean—that lofty ranges of mountains, some of them three or four miles in perpendicular height, run m different directions through these continents, some of them hundreds and even thousands of miles in extent—that hundreds of rivers, many of them above 2000 miles in length, have their rise in these elevated regions, and carry an immense body of waters into the ocean—that the ocean has been sounded with lines nearly a mile in length, when no bottom was found; that it is probable, it is several miles in depth, and that its bottom is diversified with mountains and vales like the surface of the dry land; that it contains a mass of water sufficient to cover the whole globe to the height of more than a mile and a half; and that, were its caverns drained, it would require more than 20,000 years before they could be filled by all the rivers running into it at their present rate, although they pour into its abyss 13,600 cubical miles of water every year— that the atmosphere surrounds the whole of this terraqueous mass; that by means of this atmosphere and the solar heat, a portion of the waters of the ocean is carried up to the region of the clouds in "the form of vapour, and condensed into rain to supply the sources of the rivers, and to water and fertilize the earth—and that, by these and similar arrangements of Infinite Wisdom, the lives and comforts of myriads of animated beings throughout the regions of the earth, air, and ocean, are preserved and perpetuated.
Such general views of tho grand features of the globe, when occasionally enlivened with particular details of what is curious and novel to the young, cannot but arrest their attention, and excite their curiosity to acquire more minute information on the subject; while, at the same time, they have a tendency to inspire them with sublime and reverential ideas of that Almighty Being who, "laid the foundations of the earth, who causeth tho vapours to ascend, who mcasureth the ocean in the hollow of his hand, who weigheth the mountains in scales, and taketh up the isles as a very little thing." After describing such general views, the attention may be directed to various other objects connected with the physical constitution of-the globe, such as rocks and insulated mountains, promontories, isthmuses, caverns, icebergs, forests, mines, and deserts—volcanic mountains, and island* that have been raised from the bottom of the ocean by the force of subterraneous agents— lakes, mediterranean seas, fountains, springs. whirlpools, gulfs, and water-spouts—the peculiarities of the different zones—the climates, and the distribution of plants and animals in the ditlerent regions of the earth—the atmospherical phenomena in different countries, thunder, lightning, aurora-borealis, the monsoons, trade-winds, sea and land breezes, hurricanes, and tornadoes—the distribution of tem/ieralvre in different parts of the earth —the variety of scasons in the different zones, and the reasons why all the four seasons prevail at the same moment in different countries —the changes which have been produced on the surface of the globe by earthquakes, volcanoes, the action of water, the influence of the atmosphere, and the agency of man—the varieties of the human race, the population of the globe, and the number of individuals that are daily ushered into existence, and of those who daily retire from the living world. To these views of natural scenery may next be added explanations of maps, and of the different circles on the artificial globe, of the nature of longitude and latitude, the division of the circle into degrees and minutes, the variety of days and nights, the reasons why the zones are hounded at particular degrees of latitude by the tropics and polar circles, and the mode by which the circumference of the earth and its other dimensions have been determined. The explanations of astronomical geography, such as the causes of the different seasons, the annual and diurnal motions of the earth, and the method of finding the latitudes and longitudes of places, may be postponed till the pupil proceeds to the study of astronomy.
In describing such objects as the above, and other departments of geography, illustrative maps and delineations, such as the following, are requisite :—1. A stereographic projection of the globe on the plane of the meridian, which divides it into the eastern and western hemispheres; and another projection on the plane of the eqnator, having the poles in the centre, dividing the earth into the northern and southern hemispheres. Without this last projection, which is seldom exhibited in books of geography, the relative positions of countries in Asia, North America, and other regions, cannot be distinctly traced. On both these maps, the ranges of mountains which diversify the globe, and all the rivers which flow from them, should be particularly delineated, without any other objects or distinctions, except the names of the countries, seas, oceans, rivers, and mountain-chains, in order to present to the young mind, at one view, this grand and distinguishing feature of our globe. For want of such maps on a large scale, accurately delineated, with the mountains and rivers, represented in their proportional magnitudes, no accurate nor compre
hensive ideas are generally entertained of this noble and interesting feature of the terrestrial surface. Three or four extensive chains of mountains may be distinguished, from which flow numerous ramifications, and which, with some interruptions from the sea, extend nearly round the globe. One of these chains -una through Lapland, Finland, and Northern Russia, including the Ural mountains, sending forth branches in different directions. Another runs along the southern parts of Europe, including the Alps and Pyrenees— Hungary, Persia, Tibet, including the Himalaya, and, stretehing in different directions, pass through China, Japan, and the Kurile islands towards Kamtschatka, from which another chain diverges, and establishes a connection with the grand chain of the American continent Another ridge runs along the southern hemisphere, through Africa, Paraguay, the islands of the Pacific, and New Holland; and another extensive chain runs from north to south, along the whole length of America, including the Andes, the Rocky and the Blue mountains. The pupils should be directed to trace these ranges, with all their different branches, not only along the continents, but across the oceans, where the tops of the higher ridges appear in the form of islands, their average elevations remaining below the level of the sea.—2. Another delineation should consist of an elementary map, showing the various objects connected with geography: such as continents, islands, peninsulas, isthmuses, promontories, mountains and plains, woods and forests—rivers, lakes, seas, gulfs, friths, straits, and channels —and the manner in which cities, towns, forts, roads, shoals, sand-banks, soundings, sunken rocks, and the direction of the winds, are represented in maps.—3. Delineations showing the proportional length and breadth of the principal rivers on the globe. This might, perhaps, be more distinctly exhibited by a number of rods of different lengths, gradually tapering to a point as the respective rivers diminish in breadth, from their mouths to their sources. Other delineations might represent their lengths, not in straight lines, but with all their curves and windings.—4. A chart or delineation of the comparative size of countries, lakes, and islands; so that the proportional spaces on the globe, occupied by such countries as Russia, China, Great Britain, the United States, &c. may be perceived at a glance. These spaces may be represented either by squares, parallelograms, or circles. —5. An Isothermal chart, showing the rlu mates and vegetable productions of the earth; in which the mean temperature of its different regions, the plants which flourish in them, the length of the longest days and nights, ths divisions of the zones, and other particulars may be distinctly noted.—6. A chart of geographical zoology, showing the various tribes and species of animals with which the earth is peopled, and the several regions where the different species abound. The names of the animals might be engraved instead of the names of towns, and if the chart was on a large scale, the figures of the most remarkable animals might likewise be engraved.—7. A map of Africa and America, and the Atlantic ocean-lying between them, on the same sheet, for the purpose of exhibiting, at one view, the whole Atlantic, with its islands, and the relative positions of the coasts of Africa and South America. Also, another map, on the same scale, representing the eastern parts of Asia and New Holland on the one hand, and on the other, the western coast of America, with the Pacific ocean, and its numerous groups of islands which intervene, for the purpose of showing the nearest approach which the old and new continents make to each other, and the relative positions of the islands and countries connected with the Pacific.—8. A map or chart of Moral geography, exhibiting the prevailing religion of the several countries, and the moral state of their inhabitants, which might be distinguished, cither by different colours or by different shades in the engraving. In this map the countries enlightened by Christianity, and those which are still shrouded in Pagan darkness, might be exhibited at one view; for the purpose of showing to the young what on immense portion of the world is still immersed in heathen ignorance and idolatry, and what exertions are still requisite for enlightening the benighted nations; and for the purpose of stimulating them to bear a part in those philanthropic movements which are now going forward for the enlightening and renovation of the world.—9. Views of cities, public buildings, mountains, caves, grottos, volcanoes, interesting landscapes, and whatever scenes or objects are most striking on the surface of the globe. Some of these views might bo exhibited by the optical diagonal machine formerly described.—10. Sets of coloured maps of the quarters of the globe, and its different countries, delineated in the usual way.—11. A projection of tho globe on the horizon of the particular country where the pupils reside, for the purpose of showing the bearings and distances of places from the country in which they are placed.—12. Plate globe*, on which the pupil may trace with a pencil the circles of the sphere, the ranges of mountains, the course of rivers, the outlines of continents and islands, and whatever else may tend to familiarize his mind to the general arrangements of the earth. On such
globes mistakes may be remedied and inaccuracies corrected by the application of the sponge; and, after the pupil has been for some time accustomed to such delineations, he will soon acquire a clear and comprehensive view of the outlines of the globe, and become familiar with the relative positions of its continents, seas, and islands.—13. Delineations of the comparative heights of the principal mountains on the globe—the mountains in the eastern and western hemispheres being arranged in two separate groups. On the some sheet might likewise be delineated, comparative views of the heights of different roup", arranging them into six or seven classes, beginning with views of such mountains as tho*e of Scotland, Wales, and Ireland, which do not much exceed 4000 feet, and gradually proceeding to such as the Cordilleras and the Himalaya, whose summits reach an elevation of above 20,000 feet.—14. Models of particular countries might occasionally be mode of wax or other materials, particularly of mountainous regions, for the purpose of exhibiting an idea of the scenery of a country, the windings of its rivers, and the comparative height of its mountains above the general level of its surface, No map can convey on idea of such particulars, or of the general appearance and prominent features of any country, similar to that of a well-executed model. I have seen in the Museum of the University of Edinburgh, several models of the kind to which I allude, of the vales and mountainous regions of Switzerland, in which the position of the towns, the course of the rivers, the lakes, the lines of roads, the vales, the rocks, the forests, and the comparative elevation of the mountains, are exhibited, as if one were looking down upon the country from the clouds. The only objection to such models would be the difficulty of getting them executed, and the consequent expense which would be incurred. But, if one model were accurately executed, others could easily be taken from it, on the same principle as phrenologists take casts of the human skull . By the assistance of such maps and delineations, and with the aid of a judicious textbook, comprising a comprehensive view of the outlines of physical, mathematical, civil, statistical, and historical geography, an enlightened teacher will be enabled gradually to lead his pupils forward to luminous views of this interesting subject. In describing the different countries, he should give a comprehens-ive outline of whatever is peculiar to each country, and select for particular description, whatever interesting objects of nature or art may hsso a tendency to excite the attention and gratify the curiosity of his pupils, referring them to their larger systems of geography for more minute details. In such descriptions, the do