very slightly flat, points in the earth are called the poles, because we liken the line through the middle of the ball, on which it turns round once every 24 hours, to a pole pushed through the ball. This line itself is called the earth's axis; it is about 8000 miles in length, and its two ends are called poles, the north pole, and the south pole. The earth is called a sphere, from the Greek sphaira, a ball, for though not quite perfect, it is not nearly so flat at the poles as an orange is at its stem. The line which, on a globe, is drawn round its largest part, half way between the poles, is about 25,000 miles in length, and is called the Equator, because it divides the earth into two equal parts, or hemispheres (from the Greek hemisos, half); all parts above the line, that is, on the same. side as the north pole, being north; and all below, or on the side of the south pole, south of the Equator.

If a place on the earth is 69 and a half miles, or one degree, north of this line, it is said to be one degree north latitude, and if nine degrees south of the Equator, it is called nine degrees south latitude. When we measure the distance of a place east or west, which is called its longitude, we say so many degrees east longitude or west longitude.

The spot on which we stand at noon, when the sun is just over head, is called the meridian, from the Latin meridies, midday. All other places quite north

and south are on the same meridian. When we take the longitude of a place, the point or line from which the measure is taken is called the first meridian; and the distance will be so far east or west from that meridian. A single step will place us on a fresh meridian; but on maps or globes, meridian lines are, for the most part, marked 15 degrees apart, the first on English maps being the meridian of London, or, rather, Greenwich (now almost a part of London), because there stands the Observatory, or building from which all matters that we wish to know about the earth and the stars are seen and noted for the British nation, by men of science, who are paid to do this very useful work.

The real meaning of the word "longitude" is length; and of "latitude," breadth. They are Latin words, and the reason they came to be used in the sense they now are is, that the ancient Jews, Greeks, and Romans knew much more of the world from east to west (that is, the south of Asia and Europe, and the north of Africa) than they did from north to south they therefore called any part from east to west so much of the world's length, and from north to south its breadth. Britain was thought by the Romans to be at the extreme end of the earth, and nothing was known of Africa except the north; and of course nothing at all of America.

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North, south, east, and west, are called the cardinal, which means chief, points of the compass. The others between them, as south-west, west-northwest, &c., are called middle points. Without a knowledge of these points, a sailor would not know how to guide his ship, to sail from one place to another. If any one in England or any place in the northern part of the world, wishes to know the exact points on any spot, he has only to look at the sun just at 12 o'clock, and mark the point to which his own face is turned, which will be due south; his back will be towards the north; the east to his left hand; and the west to his right. In New Zealand and other places in the south, that is, below the Equator, it would be the reverse of this. There the sun would be north at 12 o'clock; the east to the right, and the west to the left.

We divide the globe into five zones or belts, by four circles, two near the poles, called polar circles, and two called Tropics, from a Greek word trepo, I turn, because the sun never goes north of one of these (the tropic of Cancer) or south of the other (the tropic of Capricorn); but turns back as soon as he reaches either of them towards the other. The space between these two tropics (the Equator being in the middle) is called the torrid or hot zone, from the Latin torreo, I scorch, for the sun is there more

nearly over head, so that the heat pours down straight upon that part of the earth. The next two zones, north and south of the torrid zone, are called temperate zones, from the Latin tempero, I moderate, because there it is neither very hot nor very cold; and the two beyond these, again, one reaching to the north pole and the other to the south pole, are called the frigid zones, from the Latin frigeo, I grow cold; for the sun there shines in a slanting or side way, so that the heat glances off; and he is sometimes not seen at all for months at one time at the poles; therefore these places are very cold.

The north polar circle is called the Arctic circle, from the Greek arktos, a bear, because the group of stars which form what is called the "Great Bear" is in that circle. The south polar circle, on the other side, is called the Antarctic, from the Greek anti, opposite. In like manner it is because the sun appears to be near the group of stars which form what is called Cancer (the Crab) when he reaches the north tropic, that that is called the tropic of Cancer; and so the sun appears to be near the group of stars which form what is called Capricornus (the Goat) when he reaches the tropic of Capricorn.

When two or more places, not in the same longitude, are of equal distance from the Equator on one side, north or south, they are said to be in the same.

latitude. Thus the whole of these two circles called tropics are in the same latitude all round, being each 23 degrees and 28 minutes, or parts of a degree, distant from the Equator, north and south. The polar circles are the same distance (23 degrees, 28 minutes) from the north and south poles. Between each tropic and polar circle, that is, the breadth of each of the temperate zones, is about 43 degrees; the whole distance from pole to pole being 180 degrees, and from any part of the Equator to each pole half that distance, or 90 degrees, thus making the entire circle 360 degrees, or about 25,000 miles.

The meridians, or lines of longitude, are marked on maps and globes 15 degrees, or about 1070 miles, apart at the equator. There are, therefore, 24 of such meridian lines, to make up the like distance of 25,000 miles, round the earth, east or west. The earth being round, these lines, of course, approach each other as they leave the equator, and are brought to a point at each pole.

The number of degrees of longitude, therefore, east or west, always means degrees at the equator, and has nothing to do with the real distance between two places in any north or south latitude.