The world's moods

Front matter

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COFXPJGHT DEPCSm

UNIFORM WITH THIS VOLUME

II Publishers Note

This book presents in popular form the present state of science. It has been reviewed by a specialist in this field of knowledge. An excerpt from his review follows:

'7 am very pleasantly impressed by this Story of the Weather. The author tells simply and accurately her interesting tale of the world’s moods”

Signed: Griffith Taylor

Professor of Geography The University of Chicago

Weather men ma\e maps of the whole country to show the direction of the winds

By

Maryanna Heile

II

Drawings by

Jerome Graham

THOMAS S. ROCKWELL COMPANY

CHICAGO

I

Copyright, 1930, by

THOMAS S. ROCKWELL COMPANY

Chicago

Printed in United Strict of America

©CIA

28712

Contents

I The Air Around the World

What is air? What use is the air except to breathe? How far up does the air go? Why is the s\y blue? Why does sunlight loo\ yellow? What ma\es the colors in the sun¬ set? Where do the rainbows come from?

II Night and Day

Chapter I

AIR is a colorless ocean of gas that covers the •L earth. It extends, though very thin, at least two hundred miles above the earth. The gas that makes up air is really two gases, oxygen and nitrogen. Oxygen is a gas that makes things burn, and it is so active that it would burn up people if they breathed it in by itself. But it is mixed with nitrogen, which is a gas that keeps the oxygen from doing us harm.

These gases are both clear, so that if no smoke or dust or steam were mixed with the air people could see for miles and miles. But near the ground there is always a lot of dirt and water mixed with the air, especially in the big cities. Everybody breathes in a great deal of this dusty, smoky air. If they breathe through their noses the little strainers up in their noses take

What is air?

What use is the air except to breathe?

the dirt out, but if they breathe through their mouths the dirt goes right into their lungs and is very bad for them. These little strainers in their noses make the air warm in cold weather, so that it doesn’t hurt the lungs.

When the air keeps still nobody pays any attention to it, but when it moves around making the trees toss about and the dust blow in people’s eyes, and the window shades flap, then it is wind, and everybody talks about it. When the wind gets very strong, so that it makes tornadoes and hurricanes, and blizzards, then it does a great deal of damage. The air weighs a great many pounds on every square inch of the earth, but while people keep air in their lungs they don’t feel the weight on the outside.

Everybody in the world keeps on breathing air—about sixteen breaths every minute—as long as they are alive. But the air is good for other things. Waves travel on it just the same way that waves go on water in a lake or river. When a stone is dropped into water it makes

*3 ripples that get wider and wider and finally die out some distance away from the stone. The air has sound waves just like that. When a sound is made in the air, waves go away from the sound and die out some distance away. Near to the noise the waves are big and the sound is loud; farther away the waves are small and the sound is faint; far away it cannot be heard at all.

The air can carry several kinds of waves at the same time. The sun is very hot, so hot that although it is millions of miles away it can send heat to the earth. The heat travels through space on heat waves. When the earth gets warm it sends out heat waves, too, so that on a hot summer day people get heat from two direc¬ tions, up from the earth and down from the sun. Smell waves travel on the air as the others do, but for shorter distances.

Not long ago a wise man in Italy named Mr. Marconi discovered that he could send out an¬ other kind of waves by using electricity. Those waves were a kind of sound waves. They certain waves

How far up docs the air go?

M

could be caught by a little machine that is called a radio. Now everyone can hear music and speaking coming through the air.

The clouds float around in the air until they are ready to come down in rain. Balloons and airplanes travel through the air. Trees and grass and plants of all kinds get the gas called nitrogen from the ground and make it into food for us to eat. The corn and wheat that people eat have nitrogen in them that the plant got out of the earth and stored up in the grains.

Not long ago an army aviator went up in a balloon to see how far he could go above the earth. He got up eight miles. Up there the air was so thin that he could not breathe and was just able to get his balloon started down before he fainted. It was so cold up there that he froze his face. Little balloons without any¬ body in them have gone up as far as twenty-five miles above the earth.

The higher up a person goes above the earth, the thinner the air gets, so that after a while people cannot breathe and must come down.

i5

It gets colder and colder the higher up it is until it is more than one hundred degrees below zero. The sun’s rays seem to go through the upper air without making it any warmer. The air is in layers one on top of the other, each one thinner than the last. The one that is around the earth is the thickest.

The sky isn’t really blue at all; it just looks blue. Aviators who have gone up five or six miles into the sky say that it is black. There is no color there at all; it just looks blue to us.

The reason for the blue color that everyone sees is this: The sun’s rays are made up of a mixture of all the colors there are: violet, blue, green, yellow, orange, red. When these colors are all mixed together people’s eyes see white. When there is no sun at night and no colors at all, people see black. It means that there are no light waves around. Black isn’t really a color; it is just no color at all.

But these colors in the sun’s rays are each one a little wave in the ether. The red waves are the longest, the orange ones are next longest,

Why is the sf(y blue?

i6

A rainbow in a sprinkler then the yellow and green and blue ones, and the violet waves are the shortest of all.

When a wave in the lake strikes the shore it breaks all up into bits of water and foam. When a ray of sunlight strikes something thicker than air, like glass or water, all the little color waves break up, so that instead of white light there are colors. Sometimes the sun shining through a goldfish bowl will break up into colors; sometimes a piece of three-cornered glass will do it; sometimes the sun shining through the spray from a grass sprinkler will make little rainbows.

The air is never clean. It is always full of smoke and grains of dust and tiny drops of water. When the sun shines through all those little particles they turn aside the shortest waves. The shortest waves are the blue ones. When so many of them have been taken out of the sun¬ shine and turned toward us the sky looks blue to persons living on the ground.

If the day is very clear, perhaps after a rain has washed most of the dust out of the sky, the l 7 sunlight will look white. But on a day when there is much dust and dirt in the air the sun¬ light slanting across the fields and houses near evening looks as yellow as gold. That is because the bits of dirt in the air have taken out a great many of the blue waves out of the sun¬ light. When the blue waves are taken out the yellow ones show up more. That is why the sunlight looks yellow. It looks yellower in the late afternoon because it has farther to go when the sun is over in the west, and so has to go through more dust, so that more of the blue waves are taken out.

Sometimes when the sun is ready to go down, so many of the blue waves have been taken out of the sunlight that only the orange, red, green, and violet waves, are left. Then these colors show in the western sky and people see a fine sunset. Sometimes conditions are so that there is very little color to be seen in the sunset. Then we know the light is not being interfered with.

If there are clouds near the sun when it sets the red rays go up and strike the clouds and are

Why does sunlight loo\ yellow?

What maizes the colors in the sunset?

A sunset has lovely colors i8 reflected back in pink and lavender. Fog and smoke and dust will make the sunsets even more beautiful, for there are then more particles in the air to break up the white light of the sun.

When great volcanos have erupted, throwing into the air a great lot of fine dust, the sunsets

Volcanoes throw up clouds of dust from inside the earth to ma\e trouble in the air are very beautiful. Some great eruptions of volcanos have made so much dust that some of it floated all over the world. A hundred and fifty years ago a great volcano in Iceland opened and blew into the air much dust as fine as

*9 powder. It was really rock ground up fine down in the volcano. For six months this dust made a thin smoke all over Europe, frighten¬ ing people everywhere. Since people didn’t know what caused it they thought that the end of the world was coming.

The sun looked red through the dust, which scared them all the more. They gave away their farms and dug their graves and got all ready to die, but the dust settled down finally and the rains washed it away, and the people forgot how frightened they had been and went back to their work.

When it rains and the sun is shining, a lovely half circle of colors comes in the sky just opposite the sun. That is a rainbow. It is always in the sky across from the sun; it comes only when the sun shines through the rain. Usually on the top of the bow is red, then yellow, then green, then blue, and on the bottom, violet. Sometimes the colors are in the opposite order and sometimes some of them are missing.

The old Greek people have a story that the

Where do the rainbows come from?

rainbow was placed in the sky by Zeus, the king of the gods, as a pathway for Iris, who was the messenger of the gods, when she carried mes¬ sages to the other gods. They thought that the bow of colors reached from one side of Heaven to the other. In other stories the rainbow is the scarf of many colors that Iris wore about her shoulders. She ran so fast that the scarf was blown out across the sky.

The Indians in America had a pretty story that the rainbow was made up of the souls of the dead flowers. In Longfellow’s poem, “Hiawatha,” the little Indian boy asked his grandmother what the rainbow was.

“And the good Nozomis answered:

’Tis the Heaven of flowers you see there;

All the wild flowers of the forest,

All the lilies of the prairie,

When on earth they fade and perish t Blossom in that heaven above us ”

But what really happens when the sun shines while it is raining is that the beams of sunlight passing through the millions of raindrops are

Nozomis explained to Hiawatha what made the earth and s\y and the colors of the rainbow broken up into the six colors. The water in the raindrops is thicker than the air. First it breaks off the red color waves of the sunlight, then the orange, then the yellow, then the green, then the blue, then the violet.

If two showers come one right after the other, sometimes there are two rainbows, one below the other. People used to say that there was a pot of gold at the foot of the rainbow, and many people went out to look for it, but no one ever found it.

Once a man had a field that he was too lazy to plow. One day a rainbow ended in this field. His neighbors told the lazy man that if he would dig in the ground he would find the pot of gold. So he went out and dug all over the field, but he did not find the gold. Since he had the field all plowed up he planted some wheat and grew a fine crop, which he sold for a great deal of money. The moral of the story is that work is better than gold.

Chapter II NIGHT AND DAY

ALL of the light on the earth comes from ■L the sun. The sun stands still up in the sky, but the earth doesn’t stand still at all. It makes two different kinds of movements. First, it turns all the way around, like a top spinning, every day. Second, it makes a trip all the way around the sun once a year. That is, the earth turns itself, so that we go around in a little circle every day and night. It does that three hundred and sixty-five times in a year, but while it is turning in this little circle it makes one big circle around the sun.

When the earth is making the little circle every day, one-half of the world is turned toward the sun and one-half of it away. When any part of the earth is turned away from the sun it is dark there and people say that it is night.

Why does it get dar\ at night?

The half of the earth that is turned to the sun gets light, and they say that it is day.

The first thing that people thought about was the sun. It gave them heat and light, and when it was dark they were afraid. The first people on the earth worshipped the sun as a god. They built temples to the sun and burned sacrifices on the altars to make him kind to them.

The Indians had a story that a brave young warrior named Wabun brought the morning. He chased the dark away by shooting at it with silver arrows. They thought that it was the crimson paint on his cheeks that made the streaks of red in the eastern sky in the morning.

The Greeks were for a time worshippers of the sun god, whom they called Apollo. He drove the chariot of the sun across the skies every day. Four strong horses were harnessed to the chariot. It was made of gold and silver, set all about with diamonds. When the horses were harnessed Dawn threw open the gates of the east and Apollo drove the chariot in which was the flaming sun, up a steep pathway to the

NIGHT AND DAY top of the sky and then down to the west, where Tethys, the goddess of the sea, was waiting for him. She carried Apollo and his sun chariot

Apollo drove the chariot of the sun across the s\y between dawn and dar\ every day in a boat back to the east to be ready for the next day’s journey.

In most countries there is a time after the sun goes down that people call twilight, or half light. This light gets dimmer and dimmer until, after half an hour or so, it is really dark.

The reason that it does not get dark all at once when the sun goes down in the west is that the sun’s rays travel in waves. These waves do not always go in a straight line.

Why doesn’t it get dar\ all at once?

2 6

What ma\es moonlight?

Some of them come up over the curve of the earth in the west and make light even after the sun is gone. As the sun gets farther and farther down, fewer light waves can reach us over the edge of the world. Finally they do not come at all and it is really dark.

It never gets entirely dark on the earth. There are always a few light waves getting around to the side that has no sun. The stars give a little bit of light. Some animals, like the owls and cats, can see in the dark. Their eyes are made to use the tiny bits of light that are on the earth, even after it seems very dark to people with common eyes.

The moon travels around the earth in just the same way that the earth travels around the sun. The moon does not turn around like a top the way the earth does. It only shows one side of itself to the earth.

There isn’t any air around the moon, and it is a cold land without any people or plants or animals. It is just rocks and mountains and deep valleys of stone. Because it hasn’t any

NIGHT AND DAY

V air, or trees or grass, the moon is like a big round looking glass that reflects the light of the sun. When the moon shines on the earth with a strong white light, it is just the light of the sun being reflected back from the moon onto the earth, in just the same way that a lamp is reflected in a mirror hanging on the wall.

Moonlight is sometimes quite bright, but it is never warm. The light waves from the sun can strike the moon and come back to the earth, but the heat waves cannot. Some of the color waves that are in daylight are not in moonlight, so that colors like red, green and purple don’t show up very well under the moon.

Artemis, the goddess of the moon, was the twin sister of Apollo. She was the goddess of the hunt, but she helped to protect the animals of the wood, especially the deer. Her brother took care of the day and the sun, but she was queen of the night and the moon.

The moon goes around the earth once a month. Part of that time the shadow of the earth gets in between the sun and the moon, so moon

What ma\es the days longer in the summer than in winter?

that only part of the moon shows. One reason that we know the earth is round is that the shadow of the earth on the moon is always round. Once every month for two or three days the shadow of the earth does not come near the moon and then people say that it is full. It gives much light then.

The earth goes around every day just like a top spinning, but a top stands straight up while it whirls around. The earth turns a little bit, first toward the sun and then away from the sun. The north pole is up on top of the world. If the earth just went round and round the north pole would never have any light. All the light and heat would strike the center of the earth, down around South America. But the earth moves for six months so that the north pole is turned toward the sun for that time. Then it turns back again and for six months the people up near the north pole have a long night, while the people down near the south pole have a day that lasts six months.

When the earth turns so that the north is

NIGHT AND DAY

2 9 toward the sun we have longer days and shorter nights and we call it summer. When the south pole is turned toward the sun our part of the earth is farther away from it and the days are shorter and the nights longer, and we call it winter. The axis about which the earth turns always points to the Pole Star—called Polaris.

Up in the Arctic the weather is so cold that nothing can grow for about nine months of the year. Most of the time the ground is all covered with snow and ice. No trees can grow there, so that the people have learned to build their houses out of blocks of ice. They make them round like half of a ball. If the roofs were flat the weight of the snow might cave them in.

Inside of the house is a bench all around the wall where the family sit to work and use for a bed. In the center of the floor is a hole for the fire. Often the house is very smoky, but if it is warm the Eskimo does not care. To help keep out the cold, the door outside is at the end of a long passageway which is just high enough for a person to crawl through. The Eskimos use dogs to pull their sleds, because horses could not live in the cold. The dogs sleep in the passage at night.

The Eskimos live on seal fat, which we call blubber. It has a fishy taste and is very oily and they eat it without cooking, but it keeps them warm through the long winter. They sometimes have reindeer meat. The reindeer live in very cold countries by eating the moss that is under the snow.

Although there is no sun for six months in the far north, it is not very dark because the stars give some light and the Aurora Borealis that shines like a great rainbow in the northern sky all winter long makes pink and purple and blue lights on the snow.

Chapter III HEAT AND COLD

W HEN the earth turns toward the sun around the imaginary line called its axis, during our springtime and summer there is more heat here because we get the sun’s rays more nearly straight. They are hotter because they do not have quite so far to go and they do not lose so much heat as they come through the air. The sun is very hot at the equator, which is an imaginary line drawn exactly half way between the north and south pole. It is not so hot further away because the rays must travel in a slanting direction through the air to reach the earth and some of the heat is lost.

On June twenty-first of each year the earth has turned so that the north pole is looking toward the sun. Then the days in the United States and Canada are about fifteen hours long.

Why is it hot in the summer time?

On December twenty-first the north pole is turned as far away from the sun as possible, and on that day we see the sun for only about nine hours.

During the long days the ground gets hot and does not cool off very much during the short nights. That helps to keep the earth warm in the summer time. Of course, while the people in North America are having sum¬ mer because the earth has turned on its axis toward the sun, the people in South America are having winter because their country is turned away from the sun.

All the seasons of the year are caused by this turning of the earth. If the earth stood up straight all of the time and did not turn toward the sun and away from it, we would have just one kind of weather all the time. Since North America is a long way north of the equator, where the sun would be shining if the earth did not turn, we would have fairly cold weather, about the kind of weather that we have now in March and September. Not many of the trees

HEAT AND COLD and plants that we have would grow very well if it were that cold all the time.

In December, January, and February, the earth is turned away from the sun in this part of the world. It is turned so far that up where the Eskimos live they do not see the sun at all. In the United States we get some of the sun’s rays, but they come to us so slantingly that they have lost much of their heat and do not give us very much. Then we have ice and snow and cold weather. The great amount of ice and snow in the north help to keep it cold there after we have spring, but often the summers in Alaska are warm and pleasant.

The countries that are near the north pole and the south pole never do get very much heat from the sun even when they are turned toward it. They are too near the top and bottom of the earth and the rays of the sun strike them too slantingly. Up in Canada the summers are short and only a few kinds of grains that will grow and get ripe in three or four months can be raised. In the northern parts of Russia they

Why is it cold in the winter time?

have very short summers, too, and can only raise certain things.

At the earth’s equator the sun shines very hot all the time and, where there is rain enough, the trees and other plants grow very large and tall. The people there do not have to worry much about clothes to wear because it is so hot, and they do not work very hard to grow things to eat because in the great heat plants grow very fast. They can often just go out and pick a dinner off a tree. Cocoanuts, bananas, breadfruit, and oranges, grow without any help from the people who eat them. It is so warm that they do not have to worry about houses either.

As the summer goes on, the earth slowly turns back so that the equator is directly under the sun, and the weather gradually gets colder. We call that time fall. Then comes the cold winter. After the winter the earth turns again and we have warmer weather, or spring. Every year the same thing happens in the same way.

The old Romans had a goddess that they

HEAT AND COLD called Ceres, who, they thought, made the sea¬ sons come and go. They thought that for six months she was mourning for her daughter who had been stolen away from her. During that time she was sad and did not let anything grow upon the earth. Then for six months her daughter came back to her and she was happy and made the trees bloom and the crops grow.

The air around the earth is in motion all of the time. When it is warm it gets lighter and then it rises and cold air comes in to take its place. There are some high mountains where the sun never melts. The air from these moun¬ tains gets very cold and flows down on the plains, making them cold.

Sometimes wind blowing over the ocean gets very cold before it blows on the land. Clouds get between the earth and the sun and keep the sun’s rays from striking it, so that the earth gets cold even in the summer time. Rain may fall and use up the heat that is near the ground to dry up the water. There are so many things that can happen to change the weather that it

Why are some summer days cold?

is seldom the same for more than a day at a time. We ought to be glad this is so, for people would soon become tired of the same weather day after day.

The snow is cold, but it turns the country into a clean, white fairyland

Chapter IV

W HEN a kettle boils on the stove, steam comes from it. The steam looks white near the kettle, but a little way from the fire it disappears. When a pan of water is set on the radiator for a few days the water vanishes. When it rains the sidewalks are wet for a time, but before long they are all dry again. Where does the water go?

The water evaporates. That is, it dries up. It turns into tiny drops like steam, so little that they cannot be seen, and they float off in the air. The air always has some of this mois¬ ture. Sometimes it is called vapor. Even if the land is very dry, there is water in the air, because the rivers and lakes and oceans give up some of their water to it. The moisture is carried by the winds even over deserts.

What ma\cs water dry up?

3 «

Where does the rain come from?

When a tin can of cold water is taken into a warm room, drops of water gather on the out¬ side of it. Since the water could not climb out of the tin can it must be the vapor in the air settling there. If the tin can was in a desert place where there had been no rain for months the water drops would form on the outside just the same. It might be water evaporated from an ocean hundreds of miles away blown there by the winds.