CHAPTER XIII.
A RAINY DAY.
It was raining, but no one was surprised. They had expected it.
The day before had been one of those warm, midsummer days, beginning with a clear sky and a strong south wind. By noon heavy white clouds that looked like heaps of down floated slowly overhead.
[Illustration: The weather vane.]
The weather vane, which in the morning had pointed to the south, turned from side to side, as though uncertain which direction it liked best. Toward afternoon it seemed to settle the question in favor of the east.
The clouds did not rise higher and become thinner and more scattered, as such clouds do if the weather is fair. They kept their white, billowy edges, and rested heavily on straight bands of dull gray.
When the sun set, the scroll—like edges of the clouds were tinged with gold and rose color, but under the glittering fringe remained the solid banks of gray and misty purple.
The thermometer had been high all day, for it was very warm. The barometer had slowly but surely fallen.
Then, too, the Weather Report, just received, told of a storm that had started in the southwestern part of the country and was moving northeast. Uncle Robert had said, at the rate it was traveling, it might reach them some time the next day.
And now it was raining in a quiet, steady way. The clouds had lost their billowy whiteness. They were one dull, heavy, unbroken mass of gray. The wind blew steadily from the southeast.
A rainy day was before them.
"The very thing we need," said Mr. Leonard. "The corn is just ready for it, and the pastures are beginning to look pretty dry."
"Let's go fishing, Don," said Frank. "I'll go and dig some worms while you get the lines ready."
"Say we do," said Donald, starting off at once.
"Do you want some company, boys?" asked Uncle Robert, smiling.
"You bet-ter believe!" said Donald, catching himself just in time.
"Hurrah for the rainy day!" cried Frank as he pulled on his rubber boots and coat and went out to dig the worms.
"Shall we take the boat?" asked Uncle Robert.
"Oh, yes," said Donald. "I'll get the oars."
"We'll have fish for dinner to-day, mother," said Frank.
"Be sure you come back in time, then," said Mrs. Leonard, smiling.
"I wish I was a boy and could go fishing in the rain," said Susie as she watched them start off.
Down the hill they went, and Susie, watching them from the front porch, saw them push the boat from the landing and throw out their lines as they drifted down the stream. Then the trees hid them from sight.
It was dinner time when they returned.
"I told you we'd have fish to-day," said Frank triumphantly, holding up a string of bass and perch.
"You boys will have to clean them," said Mrs. Leonard. "Jane is ready to cook them now."
"Come on, Don," called Frank. "My, won't they be good!"
In the afternoon it ceased to rain. It became lighter and the clouds looked higher and thinner.
"It's going to clear off," said Susie, going to the window.
"I wonder how much rain has fallen," said Uncle Robert.
"I'm going to look at the rain-gauge," said Frank.
"I'll go too," said Donald.
When they came back they said there were fifteen inches of water in the measuring tube, which, in the receiver, would be an inch and a half.
"That would just fill it," said Donald.
"Does that mean," asked Susie, "that if the rain had stayed on the ground it would be an inch and a half deep all over?"
"Yes," answered Uncle Robert.
"Would that be very much?" she asked, taking the rod by which the rain in the gauge was measured and finding the mark for an inch and a half.
"We might find out how much it would be on Susie's garden," said Uncle
Robert. "Does any one know how large the garden is?"
No one knew.
"Let's get father's tapeline and measure it," said Frank.
"Oh, do," said Susie, always interested in anything about her garden.
When they came in Donald said:
"It is muddy, but it's beginning to dry off in some places already."
"How big is the garden?" asked Susie.
"It is forty feet one way," said Frank, "and twenty-five feet the other."
"Take your paper and pencil, Frank," said Uncle Robert, "and draw a plan of it. You might make one inch for every ten feet, and see how that will come out."
Frank took the paper, pencil, and ruler, and soon he said:
"It makes it four inches long and two inches and a half wide."
"But remember," said Uncle Robert, "that means forty feet long and twenty-five feet wide."
"I'll write it down," said Frank; "then we'll remember."
So he wrote "40" on the long side and "25" on the short one.
"But we must find out how many square feet there are on the whole surface," said Uncle Robert.
"Well," said Frank, "there are forty this way."
"So we might think of it as a row across the garden of forty square feet, might we not?" suggested Uncle Robert.
"Yes," said Frank; "and if we do that there will be twenty-five rows just like it, won't there?"
"Exactly," said Uncle Robert. "How many does that make in all?"
"Twenty-five forties," said Frank, pencil in hand. "Why, that's just one thousand."
"That sounds pretty big," said Susie.
"Especially when you think of the weeds," said Uncle Robert, smiling,
"How many square inches would that be, Frank?"
"Well," said Frank, "a foot is twelve inches long, and if it is square it is twelve inches wide, too."
"Then," said Uncle Robert, "if you call them rows of twelve square inches, how many rows would there be?"
"Why, twelve," said Donald.
"And so it would be—"
"One hundred forty-four," said Frank.
"Then," said Uncle Robert, "if there are one hundred forty-four square inches in one foot, how many in one thousand feet?"
"One hundred forty-four thousand," said Frank, after a moment's thought.
"But the rain-gauge says that an inch and a half of rain has fallen," said Uncle Robert, "and when an inch is as deep as it is long and broad, it is called a cubic inch. How much would one and one-half cubic inches be?"
"If this is one inch," said Frank, looking at the paper, "half an inch deep would be half of this, and that, added to this, would be an inch and a half. Isn't that right?"
He went to work again, and after a few minutes' silence he said:
"It makes two hundred and sixteen thousand inches in all."
"What kind of inches did we call them, Donald?"
"Cubic inches," said Donald.
"If you were to bring a pail of water from the spring," said Uncle
Robert, "would you say you had so many inches of water?"
"No," said Frank, "it would be quarts, or gallons, or something like that."
"Do you know how much a quart or gallon is, Susie?" asked Uncle Robert.
"Mother has a quart cup in the pantry," said Susie, "that she measures the milk in sometimes, but I don't know how much a gallon is."
"My new milk pail," said Mrs. Leonard, who sat beside the window sewing, "holds just two gallons."
"Let's see how many quarts it takes to fill it," said Susie.
So they went into the kitchen, and Susie dipped the water with the quart cup into the tin pail.
"Eight," she said, when the pail would hold no more.
"If the pail holds two gallons, Susie." said Uncle Robert, "how many quarts are there in one gallon?"
"Four." said Susie, counting on her fingers.
[Illustration: Two gallons. One quart.]
"Well," said Uncle Robert as they went back into the dining-room, "now we have found how many quarts there are in a gallon; how shall we find how many gallons two hundred and sixteen thousand cubic inches will make?"
"If I knew how many cubic inches there are in one gallon," said Frank,
"I could do it."
"How shall we find out?" asked Uncle Robert.
"We might measure a gallon," said Donald, "and then if we could empty it into a flat pan couldn't we measure that?"
"We can try," said Uncle Robert, "if your mother has the pan."
"You may use one of those tins I bake biscuit in," said Mrs. Leonard.
"I'll get it," said Susie.
They measured it and found it was eleven inches long, seven inches wide, and two inches deep. The gallon of water filled it one and one half time.
"If it had been three inches deep," said Frank, "the water would have just filled it."
"Well," said Uncle Robert, "can you find out how many inches there are in all?"
It took some time and several suggestions from Uncle Robert, but at last they found it to be two hundred thirty-one cubic inches.
"Now," said Uncle Robert, "can you find how many two hundred thirty-one cubic inches there are in two hundred and sixteen thousand cubic inches?"
"I know how," said Frank, figuring rapidly.
In a short time he found that two hundred and sixteen thousand cubic inches would make over nine hundred thirty-five gallons.
"If you were going to water the garden with the new two-gallon pail," said Uncle Robert, "how many times would you have to fill it?"
"If we took two gallons at a time," said Frank, "it would be—wait a minute—it would be four hundred sixty-seven and one half."
"My," said Donald, "it makes my arms ache to think of it."
"I'm going to find out how much fell on the whole farm some time," said
Frank, "but I'm just tired out now."
"Where does all the rain come from?" asked Susie. "I don't see how so much water can stay in the clouds."
"It doesn't," said Donald, laughing. "That's why it rains."
"But where does it all go to?" asked Uncle Robert.
"Oh," said Susie, "it just goes into the ground."
"Some of it runs off into the river," said Donald. "That's what makes it rise when it rains hard."
"I wonder if it has risen much to-day?" said Frank.
"We might put on our rubber boots and walk down and see," said Uncle
Robert. "It is clearing off finely."
"It is almost supper time now," said Mrs. Leonard. "If you'll wait I'll help Jane get it ready, and then you can go as soon as it is over."
So they waited, and by the time they started the sun was shining brightly. It would be a whole hour before it would set.
CHAPTER XIV.
THE WALK AFTER THE RAIN.
The sky was clear and bright as if it had been washed by the rain. The trees took on a fresher green. The corn held up its tasseled heads as if conscious of the strength the clouds had given it. The birds, too, rejoiced as they flew from tree to tree, singing their sweetest songs.
"How nice it is to get out after being in the house all day," said
Susie, skipping along by Uncle Robert's side. "See that lovely blue sky.
I wish I had a dress for my doll just that color."
"And when we came out this morning," said Uncle Robert, "Donald thought the clouds looked as though they were solid and could never break away."
"They're all gone now," said Donald. "I wonder where they went. Aren't the clouds lovely sometimes, uncle? I love to watch them when they look like great piles of snow."
"Yes," replied Uncle Robert, "when I was a boy I used to lie for hours under an old apple tree and watch the clouds. I fancied they had very wonderful forms, sometimes giants and dragons and all kinds of animals."
[Illustration: The clouds.]
"You can see things in them," said Donald. "I often do."
"What are clouds made of, uncle?" asked Susie. "I wish I could get close to one and see what it is like."
"When people go up in balloons," said Donald, "they go through clouds sometimes."
"Have you never been in a cloud?" asked Uncle Robert, smiling.
"Oh, no," said Susie. "How could I? I've never been up in a balloon."
"I know," was the reply, "but have you never seen anything near the ground that looked at all like a cloud?"
"I don't remember," said Susie, shaking her head.
"We've seen fogs along the river," said Frank. "They look a little like clouds. You know we see them almost every morning."
"Oh, yes," exclaimed Donald. "Don't you remember that fog we had early last spring? Why, uncle, it was so thick we couldn't see the barn from the house."
"And, uncle," said Susie, "I went out to the barn with father, and in a few minutes there were little drops of water on my hair, and all over my cloak."
"Did it last all day?" asked Uncle Robert.
"Oh, no," said Frank, "only for a little while in the morning. Then it went away and the sun came out."
"How did it go away?" asked Uncle Robert.
"Why," said Donald, "at first it began to get lighter, and we could see things plainer."
"And then," chimed in Susie, "it looked as though the fog broke up into pieces that rolled up in the sky, and floated off just like clouds."
[Illustration: The gully.]
"But what is that we see over the bottom land yonder?"
"It looks like fog," said Frank.
"More like steam, I think," said Donald.
"If it was up there against that blue sky instead of on the ground—" said Uncle Robert.
"Then it would be a cloud," said Susie. "Why, I never thought of that."
They had gone through the gate in front of the house, and were following the path that led down the slope to the spring.
"See how the water has plowed through the ground," said Frank, pointing to a gully the rain had made in the path.
"It took a good many rains to make that gully," said Donald.
"There was a little creek here for a while," said Frank. "The water has all run off now, but it has spoiled the path."
"Will the gully get deeper every time it rains?" asked Susie.
"Of course," said Donald. "That's what makes it."
"Why does the water run along the path?" asked Uncle Robert.
"Because it is lower than the ground on each side," said Frank.
"How deep do you think the water will dig into the path if we do not fill it up?" asked Uncle Robert.
"Oh, way, way down. I suppose," said Donald.
"But if grass grew on the path," said Frank, "the water wouldn't wear the ground away. We will have to fill it up with stones."
"See these pebbles, uncle," said Susie. "How did they get here? They look just like those we saw on the island."
"Do you remember what I told you about the bowlders on the island?"
"Yes, you said the bowlders were made by ice," answered Susie. "Did the ice make these pebbles?"
"Perhaps so, and perhaps the river made them and left them here."
"What! that river away down there? How could it get up here?"
"That river away down there once flowed right over this ground," said Uncle Robert. "This slope," pointing just above, "was its bank, and the ground under our feet its bed."
"That must have been a hundred years ago," said Donald.
"Yes, a great many hundred years ago. You see the work this bit of a stream has done in the path? Many rivers begin just this way. They are cutting and changing the earth all the time."
They had now come to the spring nearly at the foot of the slope. On sultry summer days it was a cool, inviting spot. The low-spreading branches of a beautiful bur oak shaded the little stream where it gushed from the outcropping limestone.
"Do you want a drink?" asked Susie, taking the tin dipper which always hung by the spring.
"Thank you, dear. How cool it is! It makes me think of the old spring in the hayfield where I used to work when I was a boy."
"The rain has not made the spring run any faster," said Donald.
"Where does this water come from?" asked Uncle Robert.
"From out of the ground," said Susie. "How does it get into the ground?"
[Illustration: The spring.]
"It's always there, isn't it?" said Susie. "The spring runs all the time. I fill my pail here every day in the summer."
"Yes, don't you remember when the wells all dried up last summer," said
Frank, "that the spring was all right?"
"Well, then, where has the water gone that fell to-day?" asked Uncle
Robert.
"Most of it has run off into the creek and river," said Donald. "It would look just like a lake if it was an inch and a half deep all over the ground."
"Some of it has soaked into the ground," said Frank.
"How deep down into the ground?" asked Uncle Robert.
"Down to China," laughed Donald.
"How deep do you have to dig to find water—to China?"
"Our wells are about thirty feet deep," said Frank. "In a dry time there's no water in them."
"How is it when you have a long wet spell?"
"They are more than half full then."
"Have both wells the same depth?"
"I think so."
"Where does the water in the wells come from?"
"It is the rain that has soaked into the ground," said Frank.
"How far down does it go?"
"It must go down till it finds some hard clay or rock that stops it," said Frank.
"What does it do then?"
"Then," said Frank slowly, "it must go along on top of the rock or clay."
"When does it come out of the ground?"
"Oh, I see! The rain goes down until it comes to that lime rock. Then it goes along the rock, and comes out there," said Donald, pointing to the spring.
"Does it always?" asked Frank. "I have read of very deep wells that are bored down into the ground more than a thousand feet, and when the augur strikes water the water comes right up to the top of the ground."
"You are talking about artesian wells," said Uncle Robert.
"Yes, that is the name."
[Illustration: Section of hillside.]
They had left the spring and were walking down toward the mouth of the creek. The rain had swollen the little stream, and the water was dark with dirt.
"See how muddy the water is," said Susie.
"The creek must bring down a lot of earth," said Frank.
"There are Joe and Dick Davis," said Donald, pointing across the river.
"I wonder what they are doing? I'm going to see."
Donald ran along to the mouth of the creek, which he reached as the Davis boys began to scramble down the steep bank to the edge of the river.
"Hello there!" called Donald. "What are you fellows doing?"
"Sticking in the mud," replied Joe Davis, holding up first one foot and then the other, heavy with the stiff clay that hung to it.
"Why don't they go around by the path?" said Susie, coming up with Frank and Uncle Robert.
"They'll always take the short cut if there is one," laughed Frank.
"Come along over here!" he shouted.
"All right," sang out Dick, scraping the mud from his shoes.
An eddy in the stream just above the steep bank made a quiet place in the current. Here their boat was moored. As they pushed out from the shore they were swept down the stream, but a few strong pulls carried them beyond the swiftest part of the current, and then they easily rowed back to the landing at the mouth of the creek, where the Leonards were waiting for them.
"I wish our bank was low like this," said Joe as he leaped from the boat. "We have to go so far downstream before we find a low bank on our side."
"I should think you'd rather walk a mile," said Susie, looking at Joe's shoes, "than come down that bank when it's so muddy."
"Humph! we don't mind a little mud," said Dick, wiping his feet on the grass.
"You've brought some of your land over to us, I see," laughed Uncle Robert. "Mr. Leonard will be obliged to you. He is always glad when the soil is left on his side."
"I don't see why it is," said Joe, "that our land is being cut away all the time and yours is getting bigger. It isn't fair."
"We can't help it, Joe," said Susie. "It's the river that does it. You ask Uncle Robert. He'll tell you all about it."
"I can tell you how it is," said Donald. "You know how strong the current is over on your side? Well, that's the reason your land is washed away. The water flows slower here, so it drops all the stuff it brings with it on our side. See?"
"My!" said Dick, with a mischievous twinkle in his eyes, "doesn't he know a lot!"
"Well, it's so," declared Donald, giving his head a nod. "You can see it yourself if you keep your eyes open."
"My eyes are always open," said Dick, "but that doesn't keep our land."
"You ought to have a creek," said Frank, "if you want your land to grow.
Just look, uncle, what a lot of dirt has been left here."
"It makes quite a delta, doesn't it?" replied Uncle Robert.
"Sure enough," said Donald. "You remember the day of our picnic we were going to see if there was one here, and we forgot it."
"Now you see where some of the dirt or silt that is brought down by the creek goes," said Uncle Robert. "And all this must have been left here since the flood in the spring. Frank is right. The creek is really building land all the time."
"Most of the dirt or—what did you call it—silt goes down the river, doesn't it?" asked Frank.
"Our land goes down the river," said Joe; "I've seen it."
"And the river is building land for us," said Donald.
"Yes," said Uncle Robert, "the river works all the time, tearing down in some places and building up in others. The clouds give us rain, the rain goes down into the ground, and then comes out and runs into the streams, and then—"
"Into the ocean," said Frank.
"And then—"
No one spoke.
"And then it rises up from the ocean and comes back again in clouds."
"Did those clouds we had this morning come all the way from the ocean?" asked Joe. "I don't see how they could come so far?"
"The clouds have swift wings to carry them," replied Uncle Robert. "They travel very far without tiring."
"The wind brings the clouds, doesn't it, uncle?" asked Susie.
"Yes, they come on the wings of the wind."
"Oh," said Joe, "I see."
"There's father blowing the horn," said Dick. "We must go."
"Come again," said Uncle Robert and the children together.
"I wish we could hear more about the river," said Joe to Frank as he helped them push off the boat.
"Come over again any day," said Frank. "Uncle Robert will tell you all about it."
"I wish he was my uncle, too," said Dick as they pulled out into the stream. "He isn't a bit stuck up and he knows a lot."
CHAPTER XV.
THE BIG BOOK.
"Please tell us another story from the Big Book," begged Susie as the family were all seated on the piazza one beautiful summer evening.
The great full moon, like a ball of molten iron, was rising in the east. It plowed a silver path across the river. Fireflies glimmered and sparkled in the dusky shadows of the meadow and in and out of the garden shrubs. The merry chirping of the crickets and the low hum of insect voices filled the air. Down by the creek the whip-poor-will told his one story over and over.
"A story from the Big Book!" repeated Uncle Robert. "There are so many and they are all so wonderful. Ever since man was created he has read stories in the earth, water, and sky, and in all living things. Everything he has found in Nature helps him to live and grow wiser and better. We could never understand printed books unless we studied the Big Book. The more we read what God has written the more we shall want to read what other people have found out and put into printed books. The true desire to read these books springs from our love and study of Nature.
"It was written for many years that the sun moved around the earth. But Copernicus studied the sun, earth, and stars anew, and he showed that the printed books were wrong by proving that the earth moved around the sun. Galileo read the same story through the telescope that he made.
"Steam had always been a very common thing. Hot vapor had risen from heated water ever since fire was discovered, but the real story of steam had not been read until Watt sat long hours by a boiling teakettle. Then came the locomotive, the railroad, and mighty engines driving wheels that work for man."
"Wasn't that a good story to read from the Big Book!" said Frank.
"Lightning had flashed and thunder rolled throughout the ages. Men feared, wondered, and worshiped that mighty hidden power. Franklin looked straight at the forked lightning and asked, 'What are you?' The answer came in the telegraph that is fast making the nations of the earth one great family. Bell listened long and carefully to sounds, and now I can talk from New York to my friends in Chicago.
"Are not these stories from the Big Book as wonderful as miracles? These are only a few of the many stories that have been read. Countless more will be read when children really open their eyes to the 'law of the Lord that converteth the soul.' Great men and great minds have road Nature's revelation in the past, but the time is coming when you and I and all children will read every day and hour the hidden things that surround us like light and press upon us like air. The Creator is writing the Big Book all the time for us—His children. Should we not read what He says there?"
The children did not understand all that Uncle Robert said, yet they loved to listen.
"We have found that our farm is a very interesting page of the Book," said Mrs. Leonard.
"Yes, that is the precious thing about it all.
"Whether we look, or whether we listen,
We hear life murmur or see it glisten."
All eyes were gazing at the moon as it seemed to rise above the trees. The great face of the man in the moon became distinct as he looked down upon the rolling earth.
"A beautiful and wonderful world," continued Uncle Robert, "but probably not a bit more wonderful than the countless worlds we see up there.
"Just think! we are on a great round ball, and it is moving on its axis from west to east toward the moon. The moon, you know, does not really move over our heads as it seems to do. The round earth rolls upon its axis, and that makes the moon seem to rise higher and higher, and then sink away below the western horizon."
"To-morrow night it will come up in the east a little later," said
Frank.
"Round and round we go upon our ball of earth. The sun seems to rise and set just as the moon does, but it is the world itself that makes the sun and moon seem to rise and set," said Uncle Robert.
"What is our earth made of?" asked Donald.
"Just what you see before you," answered Uncle Robert. "Under our feet we have the ground, the soil, gravel, sand, and loam, which is made of—"
"Ground-up rock," said Frank.
"And underneath the soil there is—"
"The solid rock," said Frank.
"And underneath that?" asked Mr. Leonard.
"We do not know, but it is quite certain the solid earth is made of ground-up rock and rock that may be ground. The mills are all at work, grinding all the time."
"The mills!" said Susie. "Where are the mills?"
"I know one," said Donald. "The river is a great mill. Don't you remember about the pebbles?"
"And the glaciers are mills, too," said Frank.
[Illustration: Glaciers on the Coast of Norway]
"Yes, the rivers, the ice rivers or glaciers, the wind, the frost, heat and cold, all grind masses of rock into bowlders, pebbles, and sand."
"The rock has been ground so long I should think there would be nothing left but soil," said Frank.
"You saw the limestone down by the spring?" asked Uncle Robert.
"Yes," the children said together.
"That limestone was once soft mud spread out upon the bottom of the ocean in shallow water."
"How do you know that is so, uncle?" questioned Frank.
[Illustration: Fossil fish.]
"There are many proofs, but the best proof is that in the limestone are found shells of animals that live in the sea," said Uncle Robert.
"Fossils," said Mrs. Leonard.
"Yes, fossils. They are the remains of plants and animals that lived a very long time ago. Many rocks are almost entirely made of fossils. Fish and shells also have been covered with soft clay and left their imprints. Great beasts have walked in the mud, and we now find their footprints in the hard stone. Coral—you have seen coral?—is often found in limestone. It is made of the shells of little animals, called the polyp, which live in the sea."
[Illustration: Coral]
"So you see that the firm ground under foot is made of rock, some of which has been ground up over and over again. But there is something else besides rock that makes the world"
"Water," said Donald promptly as he looked down upon the river.
"Yes, the water is just as much a part of our world as the solid rock and the soil. There is water in the soil and in the solid rock, too. It comes out to us in——"
"Springs," said Donald.
"Water fills hollows in the earth——"
"Ponds and lakes," said Frank.
"Water runs down the slopes—"
"Streams," said Frank.
"Rivers," said Donald.
"There is water in the air—mist, fogs, and clouds—and there is much water in the air which we can not see."
"Vapor?" asked Frank.
"Sometimes water is so thin we can not see it, and again it is so thick and hard that we may walk over it."
"Ice," said Susie.
"Tiny bits of vapor come together until they become so heavy that they fall to the ground."
"Raindrops," said Donald.
"Water is sometimes frozen in the clouds in beautiful white crystals, and then they sail down to the earth."
"Snowflakes," said Susie.
"Sometimes drops start from the clouds and go through very cold air. The cold air freezes them quickly, and then they rattle on the roof and dash on the ground. They cut the corn leaves and destroy the crops."
"Hailstones," said Donald.
"Oh," said Susie, "I saw a hailstone once as big as an egg."
"The lakes are hollows in the ground filled with water. There are many small hollows, and some big ones, but there is one so great that we may call it immense. It is the largest hollow in the world—so large that it occupies three-fourths of the earth's surface."
[Illustration: Ocean islands]
"The ocean," said Frank.
"Yes, the ocean is only a great big hollow filled with water."
"How deep is the ocean?" asked Frank.
"Very deep in some places—deeper than the height of the highest mountains. In others it is very shallow. In some places bits and masses of land rise out of the ocean."
"Islands?" asked Donald.
"Four great masses of land rise above the ocean level. These immense rock masses are called—"
"Continents," said Frank.
"Yes," said Uncle Robert. "We live on one of them."
"The continent of North America," said Donald.
"Our island rises right out of the river," said Susie.
"Rock and water make only a part of our world. We live on the firm earth. But we live in something. Indeed, we live at the bottom of a great, deep ocean, deeper than the water ocean, and broader than the rock and water surface taken all together."
"We live at the bottom of an ocean!" said Donald in surprise.
"Now you are joking, Uncle Robert," said Susie. "If we lived on the bottom of an ocean we should all drown."
"Fish live in the ocean, and we live in an ocean, too—a very deep one, how deep no one really knows. It may be a hundred, or hundreds of miles deep. We see a part of the surface of the earth and of the water, but no one has ever seen the surface of the mighty ocean in which we live."
Susie and Donald were puzzled. Frank's face lighted up as he said:
"I think you mean the air, Uncle Robert."
"You are right, Frank. The great ocean in which we live is the air, or, as it is called, the atmosphere. The atmosphere is just as much a part of our world as the rock and the water. The rock we may call solid, the water fluid, and the air gaseous. Solid, fluid, gas."
"How do we know that the atmosphere is so deep?" asked Frank.
"We do not know exactly, but there are ways of proving that it is very, very deep. When people began to study the atmosphere they thought it extended about fifty miles from the surface of the earth. Now they are sure that it is much deeper. We know that air has weight, like soil and water. It presses on us and everything else—"
"Fifteen pounds to the square inch," said Donald.
"We weigh the air with the—-"
"Barometer," said Susie.
"It is heavier at the ocean level than it is on the tops of mountains.
We are sure that the higher we go up—-"
"The less the air weighs," said Frank.
"At the height of fifty miles it is thought to have little or no weight, and so people believed that was as far as it extended. But in time they discovered another way of measuring the atmosphere. You have seen falling stars, haven't you?" asked Uncle Robert.
[Illustration: Meteors.]
"Oh, yes," said the three children together.
"I saw a star fall, so fast—just like a rocket. Then the light went out, and I wondered where it went," said Susie.
"Falling stars are not stars at all, though they look like them. They are pieces of rock that break off from other worlds and whiz through space."
"Oh!" said Susie.
"Outside of our atmosphere there may be nothing for these masses of rock to strike against, but just as soon as they come into the air, it tries to stop them. The air is not strong enough to stop them, but it grinds them up."
"Grinds them up!" exclaimed Donald. "Isn't that wonderful? But, uncle, what makes them look just like fire?"
"If you put an axe or scythe on a dry grindstone and turn the crank, what do you see?"
"Sparks of fire," said Frank.
"Why do you put grease or oil upon the axles of your buggy?"
"To keep them from becoming hot and dry," said Frank. "One time when father and I were on a train there was a hot box, and we had to stop to cool it."
"The heat and the sparks of fire are caused by one body rubbing against another. The faster they move, the greater the heat. This rubbing is called friction."
"There was a time," said Mr. Leonard, "when fires were started by rubbing two pieces of wood together. Some Indians do so now."
"Then the great pieces of rock rub against the air when they whiz through it, and that makes the sparks?" asked Frank.
"You are right. We can see the blaze of fire caused by the friction."
"I should think the rocks would fall on us and kill us," said Donald.
"Most of them are probably ground up into bits of dust before they reach the ground. Some of them, indeed, do strike the ground, and very large ones bury themselves deep in the earth. When we go to the Field Columbian Museum, in Chicago, we shall see these visitors from other worlds. They are called meteoric stones, or meteorites. When they are in the air we call them meteors."
"I am going to watch the next one I see," said Susie.
"They fly so fast that you hardly see them before they are gone," said
Donald.
"Men who study the heavens tell of the depth of the atmosphere by the angle the meteor makes in falling, but perhaps you can not understand that now. So you see, children, we live on the bottom of a great ocean of air, and that air, or atmosphere, is a part of our world—the outside part."
"How plain it all is," said Mrs. Leonard, "when we think of it this way!"
"Now we have the land and the water," said Uncle Robert.
"And the atmosphere," put in Donald.
"And they are all right here close to us. Here is the land with its hollows, and there," pointing to the river glistening in the moonlight, "is the water, and—"
"You can't see the air," said Donald.
"We can feel it, anyway," said Susie.
"How large is the earth, uncle?" asked Frank.
"Eight thousand miles through it and twenty-five thousand miles around it," answered Uncle Robert.
"But, uncle, is it all solid rock for eight thousand miles?"
"No one knows. The rocky outside of the ball is called the crust of the earth. Miners have dug down nearly four thousand feet, and makers of artesian wells have bored still farther. They always find rock."
"I wonder how far four thousand feet would be," said Donald.
"A little over three quarters of a mile," said Mr. Leonard.
"The farther they go down into the crust of the earth, the warmer they find it. I have been down in a mine thirty-two hundred feet, and it was very hot. No one could have lived there if cool air had not been brought down from the surface.
"Some people have thought that inside the crust of the earth the rock is all a molten mass, like melted iron. You have read about volcanoes, and of the lava that is thrown out of them?"
"Does that come out of the inside of the earth?" asked Donald.
[Illustration: Down in a Gold Mine]
"It comes from somewhere in the earth. Some men give their whole lives to the study of these questions, but you know they can not see beneath the crust of the earth. It is thought by some that the weight of the crust would keep the center of the earth a solid mass. So you see there are still many questions unsettled. We know that the crust is moving up and down all the time."
"Oh, I hope the land won't rise here!" said Susie.
"You wouldn't know it, Susie, if it did," said Uncle Robert, laughing.
"Unless there was an earthquake," said Frank.
"Or a volcano," said Donald. "I'd like to see one."
"I would like to see the ocean," said Frank. "It must be grand to stand on the shore and look way off and not see anything but water."
"It is a grand sight, Frank. I have sat on the beach many a time and watched the waves roll in, and thought of the wonderful work the ocean is doing. You know it is the great reservoir that supplies all the land with water."
[Illustration: View of the Ocean]
"The heat of the sun lifts the water up, or evaporates it. The vapor that makes the clouds rises into the air. The winds blow the vapor many long miles, and some of the clouds come right over our heads. The cold air draws the little bits of vapor together and makes the clouds heavy, and down they fall upon the earth as drops of rain.
"Some of the rain runs directly into the streams. Some of the rain water sinks down into the earth; in the gravel it sinks fast; in the sand it sinks slower; and in the loam, clay, and rock it sinks very slowly indeed. The water in the ground dissolves the rock or the loose earth into little particles so fine that the tiny roots, or root hairs, drink them up, and so the rock furnishes a part of the nourishment, or food, of plants.
"Without the water that the clouds bring no plant could grow. It gives life and growth to everything that lives, and then sinks deep into the earth. It comes out of the ground again in springs, and flows away in rivulets, brooks, creeks, and rivers—away, and away, back to the ocean again.
"On its way to the ocean it wears down the land, carries silt from place to place, spreads it out on beaches, sand bars, bottom lands, deltas, and on the bottom of shallow places in the ocean."
"Isn't it strange how everything changes, and how all the changes help us?" said Frank thoughtfully.
"Yes, Frank, it is wonderful how the Creator of all things is constantly moving earth, air, and water, and, as you say, making all these changes to help man."
"It is the Big Book that tells us of this marvelous world of ours and of other worlds as well. It lies open before us for us to read every day. God has created and is still creating our home, the dwelling place of His children. We must study Him, my dear children, in all He has made. We must learn of His works in order to use everything to make man happier, better, and more useful."
Mr. Leonard, who had been listening very attentively to the story, said, as his face lighted with a happy smile:
"I never thought of it all in that way before. Every day, in all our work on the farm and in the house—indeed, wherever we may be—we should learn new and beautiful revelations from our Heavenly Father; how much He is constantly giving us, and how thankful we should be."
The moon had risen to its full glory over the earth. The waters of the river glistened. The trees, cornfields, and meadows were peaceful and grand, as though they, too, felt the power of the glorious light.
Susie put her brown arms around her mother's neck and kissed her good-night.
"Oh, how I love the Big Book!" she said.
"I wish I could read it as all those great men have read it," said
Frank.
"So do I," said Donald.
"'Day unto day uttereth speech, and night unto night sheweth knowledge,'" mused the mother as her loved ones went to bed with sweet thoughts of a beautiful world and a loving God.