Page:Maury's New Elements of Geography, 1907.djvu/20

16 four hours to go once round on its axis. This is why we have about twelve hours of sunshine and twelve hours of night.



1. The Earth Revolves.-Besides turning round on its axis, the earth moves in another way. Let us try to understand this movement. Suppose we draw a large chalk ring on the floor, or on the top of a large table, and then put the lighted lamp in the middle of the ring.

Now let us walk round the ring, holding the orange with the knitting-needle through it, so that the light of the lamp shines on it.

What we are now doing with the orange shows what happens to the earth. Nobody marks a ring for the earth with chalk, but still it goes in a ring, round and round the sun, as the orange does round the lamp. Nobody carries it, as we do our orange. It goes of itself, but it never gets tired and never stops.

It is only a few feet round our chalk ring. It is millions of miles round the earth's ring.

It takes us only a minute or two to carry our orange round the lamp. It takes the earth a whole year, all the time from one of our birthdays to another, to revolve around the sun.

1. The Seasons.—Now as the earth moves in its ring round the sun, sometimes our country receives more sunshine and heat, and sometimes less.

At one time the swallows come. The birds build their nests. The people are planting and sowing. It is now not very hot and not very cold. It is spring. The orange at 1 in the picture shows where the earth is in its path at this time.

In a very short time there comes a change. The days grow longer, the weather gets warmer. The trees are full of fruit, the melons are ripe. It is summer. The orange at 2 in the picture shows where the earth is in its path at this time.

Months pass. The leaves turn and begin to fall. The yellow corn is gathered in. Thanksgiving Day comes. It is autumn or fall. The orange at 3 in the picture shows where the earth is in its path at this time.

Again there is a change. The days grow shorter, the weather gets colder. Snow covers the hills; ice covers the ponds. Christmas and Santa Claus come. It is winter. The orange at 4 in the picture shows where the earth is in its path at this time.

These four parts of the year—spring, summer, autumn, and winter—are called the four seasons.

In some countries there are only two seasons, called the wet and the dry. In others there is one long winter with scarcely any summer.