A PUMPING ENGINE
A PUMPING ENGINE
OTHER: When we visited the water-works what did you admire most of all the things you saw, Elmer?
Elmer: The great engines that kept pumping all the time and never stopped to rest. How strange it seemed to think that they pump enough water for all the people in this great city! The houses on the hillsides as well as those on low ground have all they need.
Mother: But you would hardly think the house we live in has the most wondrous little pumping engine you ever saw, would you? Day and night it pumps “the river of life,” as the blood has been called, to every part of the body. If it should once stop, we would die, and the body-house could never be used again.
Helen: Do you mean the heart, mother?
Mother: Yes. Can you tell me where your heart is?
Amy: I can. It is on my left side.
Mother: Not quite right, little girl. The lower point is felt on the left side, it is true; but most of the heart is higher up and nearer the center of your body. Who can tell how large it is?
Percy: About the size of the fist of the person in whom it is found.
Amy: Then the baby’s heart is about as big as his dear little hand.
Mother: Can you describe its shape?
Helen: I think it is something like that of a pear or a strawberry, with the small end down.
The heart.
Mother: Here is a picture that will help us in learning its shape. I think I have not yet told you that the trunk of the body is divided into two large rooms. There is a partition running crosswise, called the di´a-phragm (di´a-fram). This gives us a large upper room, where we find the engine and bath room. The kitchen, eating room, store room, and waste rooms are in the lower part of the trunk, below the di´a-phragm. But we want to talk about the heart now. We have found about how large it is and what it is shaped like; let us next take a peep inside and learn, if we can, how it does its work.
Elmer: Didn’t you tell us once that the heart was made of muscles?
Mother: Yes; the outside walls are made of little strong muscles, and the inside is hollow. It is divided into four rooms. Each has its own name, but we will not try to learn them now. There is a wall reaching from top to bottom, and as it has no door, nothing can pass through from one side to the other. Then there are cross walls, or partitions, with folding doors in them, so there is an up-stairs and down-stairs room on each side. There are big pipes, or tubes, leading in or out from each room. They are called veins, or ar´ter-ies. The veins carry the blood to the heart, while the arteries carry it away.
Helen: But, mother, what makes the heart beat?
Mother: I thought that would be about the first thing you would wish to know, and I will explain the best I can. When the muscles which make up the heart draw together, the rooms inside become small, and the blood in them is squeezed out. When the muscles slacken, the rooms become larger, and the blood rushes in and fills them again. So the blood keeps coming in and going out of the heart all the time, and it causes it to make the movement which we call beating.
Amy: How fast does it beat?
Mother: In very little children it beats from one hundred and twenty to one hundred and forty times a minute. In grown people it beats sixty or seventy times, and when the body-house has grown old and feeble, it beats slower still. Percy, you may run up and down stairs and then tell us if you see any difference in your heart-beats.
Percy: I believe they are twice as many as they were when I was sitting still.
Mother: Hardly as many as that, but the heart beats much more quickly. Can you think of anything else that makes the action of the heart faster?
Helen: When I was frightened this morning I could hear my heart go thump, thump, and I am sure it seemed to be in a hurry.
Mother: Yes; moving quickly, fright, anger, or joy makes this busy pump work more quickly. Sadness and grief cause it to work slowly. It beats faster when we are standing than when we sit still, and the motion is slower when we lie down than when we are sitting.
Elmer: Why did the doctor put his finger on my wrist when I was sick, mother?
Mother: He wanted to know how your heart was working, so he felt your pulse. Sometimes when people are ill it beats very, very fast, and sometimes it moves more slowly than it should.
Amy: What is the pulse?
Mother: If I use any words that you do not understand you must ask what they mean. The pulse is the beating or throbbing of the arteries caused by the blood flowing through them from the heart. Have you noticed how the water sometimes goes in jerks as it is pumped through the hose pipe in the garden? It is that way with the heart. Each beat sends the blood through the arteries in jerks, and when we place our fingers on them, we can tell how fast the heart is beating. That is called the pulse.
Amy: Sometimes I think that I can hear my heart beating.
Mother: Each time it beats it makes two sounds, and they can be heard if the ear is placed over the heart. The doctor can tell by these sounds whether the heart is working all right.
Percy: But I should think it would get tired out if it keeps at work all the time.
Mother: So it would if it had no rest. Every part of the body must rest. Between the heart-beats there is just a little rest, and, though the time is very short, yet if it were all put together it would amount to six or eight hours a day.
Helen: If the heart beats sixty or seventy times a minute, I wonder how many times it beats in a day.
Mother: You may do a little figuring to find out. Seventy beats a minute, sixty minutes an hour, and twenty-four hours a day.
Elmer: I have it. It would be more than one hundred thousand.
70
60
———-
4,200
24
———-
16800
8400
———-
100,800
Mother: And this means hard work, too; for if all it does in twenty-four hours were done at once, it would be equal to lifting one hundred and twenty tons of stone one foot from the ground.
Percy: Whew! I should think this was a powerful little force-pump, sure.
Mother: But what would you think of a man who made his heart beat six thousand times more in twenty-four hours, which means that it must lift seven tons more than it should?
Amy: But I thought the heart kept working of itself. Then how could any one make it do more?
Mother: By taking only two ounces of alcohol in a day the heart would be overworked as I have said. It would not only have its regular work to do, but it would do that amount extra to throw out the poison it finds in the blood; for it knows it is an enemy. See, I have taken the pendulum off the clock for a minute. Now what has happened?
Elmer: It ticks much faster, and will soon run down.
Mother: It is much the same way with the heart of a person who takes drink with alcohol in it. His heart beats faster; his face gets red, and he can think and talk fast. It is like an engineer putting on steam and sending his train at lightning speed down a steep grade. If nothing worse happens, he will find when he comes where the track is up-grade that his power is gone and he has wasted his steam. The clock runs fast with the pendulum off, but it soon “runs down,” we say, and it is the same with the boy or the man who drinks. There are nerves which act on the heart as brakes do on the train. They keep it steadily at work and do not let it beat too fast. There is another way that alcohol hurts the heart.
Helen: Please tell us how.
Mother: It changes the strong muscle walls into fat. The heart grows larger than it should be, and becomes so weak that it can not send the blood over the body as it should. The man has hard work to breathe. He gets the dropsy and other ailments, and perhaps dies of “heart failure.”
Percy: Does tobacco affect the heart, mother?
Mother: Yes; it makes its beat unsteady, and sometimes causes an illness which doctors call “tobacco heart.” It also makes it work harder than it ought.
Amy: What can we do to keep the heart well and strong?
YOU “CAN RUN, JUMP, AND SWING.”
Mother: Be sure to give it good blood to send over the body. You need not keep still for fear that you will break this curious little pump; for, like the engines in ships, it is made to be tumbled about. Boys and girls can run, jump, and swing, yet the little engine keeps on with its steady hub tub against the walls of the house, and we would hardly know it was there. Good, honest labor makes the heart work better, and sends the blood running swiftly to every part of the body. We say when we are cold that a brisk walk will “start the blood;” that is, the heart beats more quickly, and soon the whole body becomes warm. We might say that the heart is like a clock, as well as an engine. If I do not wind the clock, what happens?
Percy: It runs down.
Mother: Does some one need to wind up your heart each day to keep it beating?
Helen: Oh, no; it just keeps going itself!
Mother: God keeps it beating, sometimes for a hundred years, without our help. I read a little poem not long ago about the heart, which I will repeat for you:—
THE CLOCK OF LIFE.
“Oh, did you ever think, my child,
That in your body dwells
A tiny clock, that verily
All other clocks excels?
“It needs no key to wind it up,
No oiling of the wheels,
No jeweler to make repairs;
With such it never deals.
“Near seventy ticks a minute is
Its normal race to go;
Just place your thumb against your wrist,
And you will find it so.
“This little clock was made to be
A faithful sentinel,
To give alarm of any change
Within its prison cell.
“If you are healthy, then its ticks
Are even, full, and strong;
By this you know that, in its cell,
Nothing is going wrong.
“When sickness comes, it works so hard,
And is so feeble, too,
It can not keep the perfect time
Its Maker meant it to.
“Now, would you help this little clock
The best of time to keep?
Then always mind the rules of health,
And thus their blessings reap.”
—Mrs. Julia Loomis.
