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What is Geography? A description of the Earth and its surrounding waters.
What is the Earth? The world on which we live. In the system of the universe, it is the third planet, in order, from the sun; its distance from which is about 95,000,000 of English miles : its mean diameter is about 7930, and its circumference 24,900, miles. * More than two-thirds of the surface is covered with water.
What are the general divisions of the Earth? The earth has been divided into four parts, called Europe, Asia, Africa, and America: to these another has been added, which includes Australia and Polynesia, or the Islands of the Pacific Ocean. Asia, the parent of nations, was the first peopled. America was not discovered until near the close of the fifteenth century, and the Oceanic Islands were subsequently found. Lands yet unknown may probably exist near the Poles, but the excessive cold renders them uninhabitable.'
* See the Sketch of the Planets annexed to this work.
one or more rivers. — A strait is, in some instances, called a frith.
Examples. The Gulfs of Finland and Mexico; the Bays of Biscay and Bengal; the Straits of Gibraltar and Malacca ; the Friths of Forth, Clyde, and Solway.
. 3. — EXPLANATION OF THE ARTIFICIAL GLOBE.
« Then stay'd the fervid wheels, and in his hand
He took the golden compasses, prepar'd
What is the figure of the earth ? Spherical or globular, only a little flatted at the poles. *
How do geographers represent the earth? By an artificial globe, on which are exhibited the continents, oceans, seas, rivers, towns, kingdoms, islands, &c., these are represented in their proper shape and situation, and the inland boundary of each state is marked by dotted lines.
What is the artificial axis of the globe ? An iron rod, passing exactly through the centre; the extreme ends of this axis are called its poles, one north, the other south. The artificial globe turns on the axis, and describes the revolution of day and night on the natural globe.
The proportion of the polar to the equatorial diameter of the Earth is very nearly as 320 to 321, and the difference about 24 English miles.
What circles are described on the artificial globe? The equator, meridians, parallels of latitude, horizon, ecliptic, tropic of Cancer, tropic of Capricorn, the arctic circle, antarctic circle, equinoctial colure, solstitial colure, and hour circle.
4. — DESCRIPTION OF THE CIRCLES, DRAWN ON THE
“ Open, ye everlasting gates, they sung;
Open, ye heavens, your living doors ; let in
Magnificent; his six days' work, a world !” Milton, . What is the equator? A line drawn exactly around the middle of the globe, dividing it into two equal parts ; the upper part of the globe, thus separated by this imaginary circle, is called the northern hemisphere, and the lower part the southern hemisphere.
How is the equator subdivided ? Into 360 parts, called degrees. What is meant by a degree? A degree on the globe contains the space of 60 geographical miles, or 69 and one-tenth of British statute measure.
What is the brazen meridian? A brass circle, which, passing through the poles, divides the globe lengthwise, north and south, into two equal parts : it has 360 degrees numbered upon it; 90 of these degrees, on each side, are graduated by tens from the equator to the north pole, and 90, on each side, from the equator to the south pole.
What is the artificial horizon? The wooden frame in which the globe is fixed; this horizon is meant to represent the real horizon which bounds our sight; on it are drawn several useful circles. What is their use? The outermost circle on the horizon shows the twelve calendar months, with the days of each month; the next, the twelve signs of the zodiac; the third, the thirty-two points of the mariner's compass ; the fourth circle is marked with the degrees of azimuth (by which we calculate the height of the heavenly bodies above the horizon, or their depression below it); and the fifth circle contains the degrees of amplitude, or, in other words, the number of degrees, counted upon the horizon, at which the stars, or sun, may rise from the eastern, or set from the western, part of this circle.
What is the ecliptic? An oblique line passing between the tropics, which shows the earth's path; this path is marked by twelve signs or constellations, extending 8 degrees north, and 8 degrees south, of the ecliptic. The space containing these 16 degrees is called the Zodiac, and the signs (or different constellations of stars) the twelve signs of the zodiac. · What are the tropics ? Two circles drawn on the globe, each 23degrees distant from the equator; the northern circle is called the tropic of Cancer; the southern circle the tropic of Capricorn. When the ecliptic touches the tropic of Cancer, or, in other words, when the sun appears to reach that tropic, (for it never goes farther north,) it is our longest day, viz. June 21.; and, when the sun (or ecliptic line) appears to reach the tropic of Capricorn, it is the shortest day to those who inhabit the northern temperate climate, viz. December 21, The longest and shortest day in our zone are called the summer and the winter solstice.
Which are the polar circles ? Two circles, one drawn north and the other south of the equator, at the distance
of 661 degrees from it, and at 23 degrees from the poles ; they mark the boundary of the frigid zone, or coldest region of the earth. The northern circle is called arctic, and the southern circle antarctic.
What are the colures? Two lines of longitude drawn through the globe lengthwise, and dividing it into four equal parts ; that line which passes through the signs Aries and Libra is called the equinoctial colure ; and that line which passes through the signs Cancer and Capricorn is called the solstitial colure. These lines serve, in the temperate zones, to show the four seasons of the year.
What are meridians ? Meridians are lines which pass from pole to pole, and through the equator, at equal distances. Twenty-four of these meridians are generally drawn upon the globe; these lines answer to the 24 hours of day and night, and are drawn at 15 degrees from each other.
What is the hour circle? A brass circle fixed on the globe at each pole, with a moveable index; it is divided into 24 hours, which are meant to represent day and night, the upper figure of 12 stands for noon, the lower for midnight.
5.-ON LATITUDE AND LONGITUDE.
“ But yonder comes the powerful king of day,
Rejoicing in the east; the lessening cloud,
What is latitude ? The distance of any place from the equator either north or south ; this distance is found