lesson image

That is how the earth moves, never turning out of its way, or changing its position in the least, but with its north pole always pointing towards the pole star in the heavens.

Hold a doll sloping towards a table on which a flashlight is standing. Fix on a bright nail in the room for your pole star, and take care always to keep the doll's face looking towards it. Then, carry the doll steadily round the flashlight, never changing its position, but keeping it always sloping a little towards the table, from the head to the feet. At one time, the flashlight shines straight on the middle of the doll. Then, move the figure round, always in the same position, and you will find the feet turned towards the flashlight, and the head turned a little away. Go on still farther; the flashlight shines again straight on the middle, and neither head nor feet are turned towards it. Go farther round and you will see the head turned towards the light and the feet away. When you get to the point where you began, the flashlight will again shine upon the middle.

It is rather difficult to keep the doll steady in the same position and always facing the pole star; but if you can manage it you will be able to understand a little how we get the four seasons.

Take an orange, then, instead of the doll, with a line round the middle for the equator, and a knitting needle put through to show where the poles should be. Put an N. at the top for the north pole, and an S. at the bottom for the south pole. Then, carry it gently round the flashlight with the knitting needle always sloping a little towards the table, and the north pole always pointing to the pole star. You will find that at one time the north pole turns a little towards the flashlight, and the south pole a little away. As you go on, the flashlight shines full on the equator and neither of the poles turns towards it. Go on farther, and the south pole turns to, and the north pole away from the light. Continue moving round, and again the flashlight shines full on the equator, and neither pole turns towards it.

We live in the northern hemisphere, about halfway between the north pole and the equator. Our warmest time, our summer, is, therefore, when the north pole turns towards the sun. Our coldest time is when the south pole is turned toward, and our part of the world a little away from, the sun, so as to get only his slanting rays. We have our spring and autumn when the sun shines straight down on the equator, and we neither turn toward nor from him. Our autumn is warmer than our spring because the sun has been shining upon us all the summer, and has made our part of the world warm. Just in the same way, a room is made warm that has had a good fire burning in it all day.

As the middle of the earth, about the equator, is the part always nearest to the sun, and is never turned from him, that is the hottest part of the world and it has not the change of the four seasons as we have.

Notebook Work: Write the answers to the questions.

1. Write the names of the four seasons.

2. Regarding the positions of the sun and the earth, what is the difference between the four seasons?

3. What part of the world is turned to the earth during summer?

4. What part of the world is turned to the earth during winter?

5. What part of the world is turned to the earth during spring and autumn?

story image