ADVANCED CLASS-BOOK

OF

MODERN GEOGRAPHY.

INTRODUCTION.

GEOGRAPHY-a word derived from the Greek ge, 'the earth,' and graphe, a description '-may be defined as the science which describes the earth not only as a whole, but also the lands and seas which constitute its surface, with their respective climates, productions, and inhabitants.

Such a description involves

1. An account of the earth as a member of the Solar System. 2. An account of the earth as a whole, its figure and magnitude, together with the determination of the positions of places, and the various methods of representing the whole or parts of its surface.

3. An account of the natural features of the earth's surface, and of the climates, minerals, plants, and animals which belong to the different regions of the globe.

4. A description of the several countries into which the earth is politically divided, with their form of government, etc.; and

5. The industrial pursuits of their inhabitants.

These correspond broadly to the five main divisions of geographical knowledge, namely:

(1) Astronomical Geography, which deals with the earth as a member of the Solar System.

(2) Mathematical Geography, which is here treated of only in so far as it relates to the figure and magnitude of the earth, and the determination of the various imaginary 'points' and 'circles' necessary to fix the exact positions of places, and the various methods of representing the whole or parts of the earth's surface by means of globes, maps, and charts.

(3) Physical Geography, which treats of the natural features of the earth, its different climates, productions, and general condition as the abode of man.

A

(4) Political Geography, which deals with the political divisions of the world, the forms of government, and the social condition of the various states and nations.

(5) Commercial Geography, which treats more particularly of the production and manufacture, distribution and exchange of commodities, and, generally, of all that affects the industrial pursuits of mankind.

The physical, political, and commercial aspects of geography are thus closely allied, and the student will not fail to notice this intimate connection between the natural conditions and productions of different regions, and the social state and industrial pursuits of their inhabitants.

For instance, the people who live in a hot country are differently circumstanced from those who dwell in a cold country, and their nodes of life will naturally be different in many respects. They will be led to adopt a different kind of clothing, and their ordinary kinds of food, their houses, their outdoor labours and amusements, with many other things, will be different in the one case from the other. In the same way the habits, manners, and ideas of people who inhabit a mountainous and rugged country will present great differences from those which belong to the inhabitants of a level plain. So also, people dwelling on the borders of the sea will have habits and occupations differing in many ways from those of people who inhabit an inland region; they will (to take one example only) be led to build ships, and thus to engage in maritime intercourse with other nations, which the inhabitants of an inland country can never do.

Further, we shall find, as we proceed with our study of geography, that the industries of a country depend not more upon its natural productions and physical conditions than upon the character of its inhabitants. Thus England has become a great manufacturing country because the abundant supplies of coal, iron, and other useful minerals and metals, have been utilized to the utmost by the industry and energy of its people. The political condition of a country is also an important factor in aiding or retarding its progress; free and just government, such as that of our own land and other enlightened countries, conduces to the development of individual and national enterprise; while despotic and arbitrary rule, as in Turkey and other autocratic countries, tends to enfeeble individual energy and to restrain commercial activity. But the most potent element of all is education, for it is daily becoming more and more evident that "knowledge is power," and the only power by which individuals and nations can hope to maintain and improve their position in the world.

The practical needs of the present day require geography to depict the earth as the abode of mankind, and the different regions of the globe as the spheres of action of the various peoples. It must furnish us with an explanation of the agricultural, industrial, and commercial circumstances, and of the poverty or wealth of each country, deduced from its situation, its climate, the nature of its surface, the character of its people, and its animal, vegetable, and mineral productions.'

1.

The Stars: On a clear, cloudless night we see the heavens thickly studded with a multitude of bright shining points or stars. The stars shine by their own light, that is, they are self-luminous, like the sun, which itself is a star.

From time immemorial, men have observed" and distinguished the stars by arranging or mapping" them into irregular groups or constellations, each supposed to represent some animal or object-the most conspicuous in our latitude being that of the Great Bear, a group of seven bright stars, two of which, called the Pointers, enable us to find the Polar or North Star.

The number of stars is incalculable, but of the millions rendered visible by powerful telescopes, not more than 6000 can be scen with the naked eye, and of course only half that number at the same time. By far the greater number of the stars are found in an irregular belt, known as the Milky Way, the dim, hazy light of which the telescope resolves into a countless mass of stars, that appear so faint and minute doubtless because of their inconceivable distance from the earth.

The stars are arranged, according to their degree of brightness, into classes or "magnitudes "-those from the 1st to the 6th magnitude only being visible to the naked eye. The nearest star, the sun, shines twenty thousand million times brighter than the brightest of the nightly stars, simply because it is so much nearer to the earth; were it removed to the same distance as a star of the 5th magnitude, it would be invisible.

The stars are at such enormous distances that it is useless to attempt to state the distance, even of the nearest, in miles. The velocity of light-light travels 186,000 miles a second-is therefore taken as a unit, and astronomers tell us that light takes 3%1⁄2 years to traverse the vast space between the earth and the nearest fixed star, while from a star of the 12th magnitude, the time occupied Annot be less than 3500 years, and from the more distant stars, 10,000 years and more!

As to the motions of the stars, they seem, with a few exceptions, to move together from east to west, round a fixed point in the heavens close to the Polar or North Star; and, while thus moving, they always keep the same position relative to one another, hence the term fixed stars. The stars thus appear as if immovably fixed in the immense hollow sphere that surrounds us, and to turn with it once a day. That this daily motion of the heavens is apparent only, and not real, is obvious from the fact that if the earth were at rest, and the heavenly borlies moved around it, the sun, at a mean distance of 91,000,000 miles, would have to travel six times that distance every 24 hours, and would tis move at an enormous and almost incredible velocity; while the stars,

at distances so vast that light takes from 3 to 10,000 years to reach the earth, would yet have to revolve in orbits of such inconceivable amplitude in the same short space of time! Further, the fact that all the heavenly bodies perform this apparent daily motion in exactly the same time' is an indirect, but conc'usive, proof that this motion must be apparent only, and is really due to the motion of the earth upon its own axis-the earth being, as it were, a "moving observatory."

The Sun: The sun, the source of light, heat, and life-sustaining power, is a star-the smallest and the nearest of the fixed starsso large that over one-and-a-quarter million globes of the size of the earth would scarcely make one globe the size of the sun, and sø distant that there is ample space between the earth and the sun for twelve thousand worlds such as ours side by side.

The sun is 109 times the diameter, and 1,279,000 times the volume of the earth, but as it is not composed of solid, but largely, if not entirely, of dense, gaseous matter in a state of incandescence, the density or mass of the sun is only 330,000 times greater than that of the earth. That is, if we draw a circle with a radius of one inch, a circle to show the relative size of the sun must have a diameter of 218 inches. A train running day and night, at the rate of 30 miles an hour, would go round the earth in a month, but would take 9 years to go round the sun. The mean distance of the sun from the earth is 91,000,000 miles; that is, light, which has a velocity of 186,000 miles per second, takes 8 minutes 9.2 seconds to pass from the sun to the earth. As to relative distance, if we represent the earth by a pea, a globe at a distance of 215 feet will represent the sun, while we should require another globe at a distance of 9000 miles to show the relative position of the nearest fixed star !?

The Planets: If the stars are closely observed, it will be seen that a few of them, apparently brighter and shining with a steadier light, do not keep the same relative positions, but move about among the fixed stars. These are the 'wanderers' or planets.

The Planets (Greek planès, a wanderer) cannot thus be classed as belonging to any of the star-groups or constellations. The stars shine by their own light: the planets are not self-luminous, but merely reflect the light of the sun, around which they revolve at various distances, and from which they receive their light and heat.

There are eight large planets, namely, Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, and 430 secondary or minor planets, called Asteroids.

The Planets vary considerably in size-Jupiter being 1,387 times, Saturn 746 times, Neptune 94 times, and Uranus 72 times the size of the Earth, while Venus is about fourfifths, Mercury one-twentieth, and Mars one-seventh part of the earth's volume. Of the 383 known asteroids, the largest yet discovered has a diameter of 599 miles, and the smallest less than 50 miles.

The earth is calculated to be at a mean distance of 91,000,000 miles from the sun-the other planets revolve round it at distances

1. 23h. 56m. 45., or a side eal day.

2. Though 'fixed' relatively to the earth and the other planets, the sun, as shown by observations on sun-stots, has two motions. It rotates on its own Axis once in 25% days, and, along with its attendant

of 35 to 2,746 millions of miles (Mercury

planets, comets, meteors, it moves through space at the rate of 420,000 miles a day, most probably in a circular or elliptical orbit round some immensely larger and more distant sun.

35.400,000 m., Venus 67,250,000 m., Mars 142,000,000 m., Jupiter 483,000,000 m., Saturn 886,000,000 m., Uranus 1,782,000,000 m., Neptune 2,792,000,000 m.). Curiously enough, if we write down 0, 3, 6, 12, 24, 48, 96, 192, and add 4 to each term, we get as nearly as possible the relative distances of the planets from the sun, i.e., Mercury 4, Venus 7, the Earth 10, Mars 16, (the Asteroids 28), Jupiter 52, Saturn 100, Uranus 196.1 The Planets all move in elliptical orbits round the Sun very nearly in the same plane, and all in the same direction, i.e., from west to east, which is also the direction of their rotation. All their satellites, or moons, except those of Uranus, move round their primaries in the same direction.

Rate of Rotation and length of day: Mercury 24 hours, Venus 23%, the Earth 24, Mars 241⁄2, Jupiter 10, Saturn 10%, Uranus 12.

Period of Revolution round the sun and length of year: Mercury 88 of our days, Venus 225, the Earth 365, Mars 687, Jupiter 4,333, Saturn 10,759, Uranus 30,687, and Neptune 60,127.

Satellites: The five larger planets are attended by satellites or moons, which revolve around them as they travel round the sun.

Of satellites, the Earth has one, the Moon; Mars, two; Jupiter, four; Saturn, eight; Uranus, four; and Neptune, one.

The four satellites of Jupiter act as a clock in the heavens, enabling sailors and travellers to find Greenwich time in any part of the world, by observing when they pass into or emerge from the planet's shadow.

Comets and Meteors: The asteroids or minor planets are not the smallest bodies which move round the sun. Countless numbers of more or less minute fragments of matter rush unseen through space, unless they approach the earth or the sun near enough to become luminous.

Meteors, or "falling stars," are such fragments ignited by friction in falling through our atmosphere. Some are so large that they are not entirely consumed, but reach the earth's surface as aerolites or meteorites.

Comets are formed of meteoric and gaseous matter in a state of extreme tenuity-the nucleus being much denser than the tail, which often extends for hundreds of millions of miles. Unlike the planets, which move round the sun at distances on the whole invariable, comets occasionally approach it so close as "almost to graze its surface," and then rush away from it to immense distances, never perhaps to return.

The Solar System: The Sun, the planets and their satellites, the asteroids, and certain comets, together form the Solar System. The Sun is the great centre and source of the light and heat of the Solar System, hence its name (from the Lat. sol, the sun). The sun, says Lockyer, throws out "as much heat from every square yard of its surface as would be produced by burning six tons of coal on it each hour," and its illuminating power is such that it gives out "as much light as 146 lime-lights would do if each ball of lime were as large as itself and gave out light from all parts of its surface." The earth, however, is so distant, and comparatively so small, that it intercepts only 17.08.000th part of the heat and light radiated from the sun in all directions.

The Earth as a member of the Solar System: Of the eight principal planets of the solar system, the earth, on which we live, is the fourth in order of magnitude, and the third in order of distance from the sun.

(a) In order of magnitude: Mercury, Mars, Venus, the Earth, Uranus, Neptune, Saturn, Jupiter.

1. From these numbers the student can easily con- | meters and distances of the various members of the struct a graphic diagram to show the relative dia- | sol? system.