A new exhibit in the Smithsonian Institute, officially known as
“Exhibit Number 56,860,” is attracting a great deal of attention from
visitors to the National Museum. It consists of a complete Haynes
six-cylinder unit power plant, and has been given a position at the
side of the original Haynes “horseless carriage,” where the striking
contrast shows the remarkable improvement that has been made in motor
design and construction during the past twenty-two years.
The most important features of the power plant are shown clearly and
comprehensively by having sections cut away from the various parts, so
that the visitors to the Institute are enabled to see the mechanical
construction, and the relation of the component devices.
On the right side of the engine, the intake and exhaust manifolds
are shown in their natural position. A full vertical section of the
Stromberg carburetor gives a good idea of how the gasoline is mixed
with the air and supplied to the cylinders. The Leece-Neville generator
has its casing cut away to give a view of the windings and cores.
Numerous windows have been cut into the crankcase to disclose the
crankshaft construction and the oil reservoir. The transmission gears
are also shown in this manner.
Most of the electrical equipment is shown clearly on the left side of
the motor. Here an interesting feature is the full vertical section
of the American Simms high-tension dual magneto. A half section has
been removed from the rear cylinder, and the piston as well, to
give a glimpse of the interior construction. A large portion of the
Leece-Neville starting motor casing has been cut away. The cover-plate
on the switch controlling the starting motor has been replaced with a
glass cover to display the method of completing the circuit from the
battery to the motor. A skeleton selector switch is mounted at the rear
of the transmission case, instead of its usual position on the steering
wheel. The electric gear-shifting mechanism is made visible by using a
glass plate for the top cover-plate on the transmission.]
Why Does the Heart Beat When the Brain Is Asleep?
Under ordinary conditions the heart beats are controlled by certain
nerve cells which are located within the heart itself, and these cause
the heart to beat even while the brain is asleep. This explains why
the heart beats when the brain is asleep, and the fact that the brain
when asleep does not exercise its functions, shows how necessary this
arrangement and the control of ordinary heart beats is. If this were
not so, we should not be able to live while asleep. It is just like
the management of a great business in this sense. The general manager
of a great business has control of the entire works, but there are
occasions when he must be thinking of only one thing in connection with
the business, and so he must have his organization so complete, that
the parts which he cannot be thinking about at the time will do their
work just the same. So he surrounds himself with competent assistants,
who look after certain departments while he is busy or away or asleep,
and if anything goes wrong while he is away, he calls on special forces
to set things right. Now, the brain is the general manager of the whole
body and has these nerve cells in the heart as a sort of assistant
manager to look after the heart beats in ordinary conditions, and to
keep the heart going while he is asleep. But, by reason of his office
as general manager, the brain has a special way of sending orders to
the heart through special nerves which run from the brain down each
side of the neck to the heart. There are two pairs of these special
nerves. One pair, if set in motion, will make the heart beat faster,
and the other pair will make the heart beat more slowly.
Why Do Our Hearts Beat Faster When We Are Running?
When you start running, the brain knows at once that your legs and
other parts of the body will need more blood to keep them going, and
so the brain sends down orders through his special nerves which make
the heart beat faster, to get busy, and they do. Then when you stop
running, your heart is beating faster than necessary--there is really
an oversupply of blood being pumped through your system for the time
being, and that makes you uncomfortable, until the brain sends word
through the other set of nerves to the heart to slow down the heart
beat. It is better to stop running gradually, to give the heart a
chance to get back to its normal beat gradually also.
Why Do I Get Out of Breath When Running?
This is also caused by your brain in its efforts to keep up your supply
of good blood. We breathe to take air into the lungs, where the blood
which has once been through the arteries and comes back on its return
trip to the heart, is exposed to the air in the lungs, before going
back into the heart. The air which we take into our lungs purifies the
once used blood and makes it into good blood again. When you run the
heart pumps blood into your arteries faster to enable you to run. Thus
also, the arteries send much more blood back to the heart through the
veins, and this must be purified by the lungs before going back into
the heart. To attend to purifying this extra amount of spoiled blood
the lungs need more air, and thus you are made to breathe in more air
for the purpose. Unless you are in good training--your wind in good
condition as we say--it is almost impossible for you to supply the
lungs with enough air for the purpose, but whether you can do it or
not, the lungs call upon you for more air, and cause you to try to get
it, and that is what makes you get out of breath.
Why Does My Heart Beat Faster When I Am Scared?
The natural tendency of a scared creature is to run or fly. The effect
of being scared has the same effect on the brain that your starting
to run has. The brain is always as quick as you are, and knowing that
when you are scared your actual or natural inclination is to run, it is
merely getting you in shape so that you can move or run fast.
Why Does Cold Make Our Hands Blue?
Your hands appear blue when cold because the veins which are near the
surface are filled with impure blood which is purplish in color. Your
hands become cold because there is not sufficient circulation of warm
red blood going on to keep them warm. The blood in circulating through
your body sends warm red blood through the arteries, and this is
returned to the heart through the lungs by way of the veins. The veins
carry only used-up blood or what is left of the good red blood when the
arteries are through with it. Its color is a purplish blue.
When your hands are blue it means that circulation of good red blood
has practically stopped--the red blood is not flowing from the heart
through the arteries in sufficient quantity and there is no color in
the arteries, as the blood from the arteries has practically all gone
into the veins. The veins are full to purplish blue blood, and this
makes the hands look blue, because there are a great many veins in the
hands close to the surface.
Why Do I Get Red in the Face?
Now, when you rub your cold blue hands together, you start the
circulation going again, and that brings the red blood into the
arteries, giving you the healthy red color again. When you run hard to
get red in the face because you are causing an unusual amount of red
blood to flow through your whole body by your violent exercise. Some
people with an extraordinary amount of circulation are red in the face
all the time. This is because of the presence of a great deal of blood
in the arteries, or because the walls of their arteries are so much
thinner than others that the red blood shows through more easily.
Is Yawning Infectious?
Yawning is infectious to the extent that other habits are. The desire
to yawn which comes to us when we see some one else does so comes under
the heading of suggestion. The power of suggestion is greater than many
of us realize. We are great imitators of each other. When one of us is
downhearted, we are apt to become happy and glad simply by being with
other people who are happy and glad. If enough people one at a time
tell a perfectly well man that he looks sick, he will actually feel
ill, provided he does not suspect a game is being played on him. So a
good actor carries his audience with him. He can make them laugh or cry
almost at will, and if he yawns, his audience will begin yawning.
Often, however, there is no acting connected with the yawning of the
first person. Then the yawn is caused because the person is not sending
enough good air into the lungs for purifying the blood, and the yawn is
only nature’s way of making us take an exceptionally deep breath of air
in at one time. This lack of sufficient good air in the lungs may not
be due to the poor breathing, but to the amount of bad air in the room.
In such cases it is quite likely that other people in the room yawn
when one of them starts it because they all begin to feel the need of
more good air at about the same time.
What Makes Me Want to Stretch?
The necessity or desire to stretch comes to us because certain parts of
the body are not receiving the proper amount of blood circulation and
it is these parts that we stretch at such times. If you have ever been
to a ball game, you know, of course, that it has become customary for
the crowd, no matter how large, to stretch its legs and arms during the
last half of the seventh inning. In fact, that has come to be a fixture
at ball games and is universally known as the “stretch inning.” Now,
it is not so much the result of a desire to encourage the home team as
the natural following out of nature’s laws that originally started this
practice. The end of the seventh inning at a ball game generally means
that the crowd has been sitting quite still for the greater part of an
hour and a half, just long enough for the circulation to become poor
in parts of the body, and the custom of stretching at a ball game thus
comes from the necessity of getting a little more speed into the action
of the heart to increase the blood supply.
In other words, the stretching constitutes a mild form of exercise. You
will notice the ball players themselves do not stretch themselves in
the last half of the seventh inning. They are getting enough exercise
without that.
It is natural, however, for us to stretch as we wake up from sleep
after having lain quietly in one position for one or more hours. It is
nature’s way of causing the heart to work faster.
What Happens When I Stretch?
What happens is simply this. When you stretch your arms and legs, you
squeeze the arteries and veins which are a part of your arms and legs,
much as happens when you pull on a piece of rubber tubing. The tubing
becomes flat instead of perfectly round, and it is not so easy to send
water through a flat tube as through a round one. Just so with the
heart. It is the heart’s business to send blood through the arteries
at all times, and when you make them flat the heart’s job becomes just
a little harder, and it goes to work beating just a little faster to
overcome this extra difficulty. By that time you are through stretching
and the heart is busy pumping blood a little faster than ordinarily,
and that is what makes you feel so good after you have stretched.
Why Can We Think of Only One Thing at a Time?
If you are asking the question intelligently, you must know that to
think means to concentrate, and in that sense we can only think of one
thing at a time, because it takes all of that part of the brain which
is used for thinking for just one thing. To give close attention to any
one subject means to turn the entire brain force practically in one
direction. To let other things pass through the mind at the same time
may appear not to interfere with the one thought, but they do, and our
conclusions suffer accordingly.
You can be doing something with one part of your body, while engaged
in thinking of one thing, but only such things as are more or less
mechanical as the result of habit, such as walking, or moving the
arms--things which the parts have done so often that actual attention
by the brain is not absolutely essential. Take for instance, the fact
that a man in deep thought on one subject will sometimes walk up and
down the room or along the sidewalk. He can do this walking and still
think concentratedly, but if he stubs his toe on the leg of a chair or
on a rough place in the walk, his thought is broken, because the brain
immediately takes itself out of the thought and pays its attention to
the toe that was stubbed.
Why Do I Turn White When Scared?
Simply because, when you are scared or frightened, the blood almost
leaves your face entirely. Under normal conditions, the red blood which
is flowing through the arteries of your face, gives the face a reddish
tinge, and your face becomes white when you are frightened, because
then the blood leaves the face. It is quite singular, but when you are
really frightened, whatever the cause may be, the human system receives
such a shock that the heart just about stops beating all together. When
your heart stops beating of course the flow of the blood from the heart
stops and then there is no supply of fresh red blood coming through the
arteries under the skin of your face. Therefore you look white--the
color your face would be if no blood ever flowed through your arteries
and veins. Some people have faces so white they look as though they
were scared all the time. This is not because they have no blood
flowing through the veins and arteries in their faces, but because
their supply of blood is less than other peoples, and sometimes because
the walls of their arteries and veins are much thicker than the average
that the color of the blood does not show through. There are also many
people who have so much blood in their systems all the time, and the
walls of whose arteries are so thin, that they look at all times as
though they might be blushing.
What Makes Me Blush?
Anything that will make your heart send an extra supply of blood into
the arteries and veins which supply your face with blood, will make you
blush. Embarrassment will do this. So will anger generally, although
sometimes people get so angry that the blood is driven out of their
faces. In this case they are so angry that their heart has stopped
beating, practically.
What Occurs When We Think?
When we think the mind is acting on sensations; it is receiving, in
conjunction with memories of sensations it has previously received.
Sensations as they reach the mind arouse the mind to activity and, as
soon as the sensation is received, the mind begins to compare the new
sensation with sensations received at previous times, and by putting
things together reaches a conclusion.
When you are thinking you are really trying to call upon memory to
help you. You know the thought of one thing calls up another, and this
leads to something else. This association of ideas is the faculty which
enables us to think consecutively and accurately. It is the business of
the mind to receive the sensations that enter it and arrange them in
their proper places. That memory of past sensations is the important
part of thinking, is proven by the fact that when we have forgotten a
thing we are unable to think what it was.
Can Animals Think?
For this reason if animals have memory they should be able to think. It
is now believed that many animals have to a certain extent the power to
remember.
A dog will recognize his master even though he has not seen him for
years. We might think he does this by his highly developed power of
smell, but if his master has come from a direction opposite to that
from which the dog first sees him, he could not have tracked him by his
smell. A dog will recognize his master from quite a distance, so he
must have to a certain extent the ability to remember or the power of
association of ideas, which amounts to the same thing. Again, a horse
that once belonged to the fire department, even though now hitched to a
milk wagon, will have the impulse to run to the fire when he hears the
fire gong. And an old war horse will prick up his ears as he used to
when he hears the bugle call.
Why Do I Sneeze?
You sneeze sometimes when you look up at the sun or at a bright light.
There does not seem to be any real good explanation of why looking at a
bright light should make you sneeze. It is due to the connection there
is between the nerves of the eyes and the nose. You generally blink if
you look at a bright light suddenly, and the blinking process stirs the
nerves inside of the nose to make you sneeze.
You know, of course, that the start of the sneeze is inside of your
nose. The nose is, besides being the organ of smell, the channel
through which we take air into the lungs, when we breathe properly.
The nose is lined with membranes, back of which are a net of very
small nerves which are extremely sensitive. The membranes are placed
there to catch and hold the impure particles of matter which come into
the nose when we take in a breath of air, and sneezing is only one
effective way of cleaning out the nose. It is brought on only when some
particularly difficult job of nose-cleaning has to be done. Pepper up
the nose will make you sneeze quickly, because pepper produces a very
great irritation inside the nose, and the nose goes to work at once to
get rid of it in the quickest possible manner as soon as the pepper
comes in. Other things have the same effect. Sometimes a cold in the
head causes you to sneeze. The sneeze in that event is merely nature’s
effort to clean out the nose when other efforts have failed.
There are many suggestions for stopping a sneeze before it takes place,
after you feel it coming on, such as putting the finger on each side of
the nose, and many others. But a half sneeze does not remove the cause
of the sneeze, so it is much better to sneeze it out, and many people
enjoy the after effects of sneezing so much that they take snuff into
the nose to produce it.
What Happens When I Swallow?
The muscles of your throat act in the form of a ring when food passes
into your throat. The food does not drop directly into your stomach. In
other words, the action is not quite the same as when you drop a stone
out of the window. When you do the latter, the stone hits the sidewalk
or whatever is below at the time, with a smash. It would hardly do to
have our food drop into the stomach, so the muscles of the throat are
arranged to contract in rings which push or squeeze the food downward,
and the food is passed from one ring of muscles to the other. It is
just like pushing a ball down into the foot of a stocking that is
apparently too small for it to drop down. You put the ball in the top
of the stocking and then by making a ring of your fingers around the
stocking you can push the ball down. When you swallow, you start the
muscles of your throat to making these rings. The upper ring squeezes
the food on to the ring below it and so on down to the stomach.
What Makes the Lump Come In My Throat When I Cry?
The “lump” which comes up into your throat when you cry is caused
by a sort of paralysis of the rings of muscles in your throat. The
muscles of your throat can make these rings or waves upward also, but
it is more difficult upward than downward--probably because of lack
of practice, as we say. When you have put something into your stomach
that makes you sick and causes you to vomit, the throat muscles take
the matter from your stomach and bring it back to the mouth in the same
way, except, of course, that this action begins at the bottom.
Sometimes when you cry, or lose control of yourself in some other
way (you know, of course, that in crying you always lose control of
yourself, don’t you) practically the same effect is produced as when
you have something in your stomach that should come out. Crying, or the
thing that happens sometimes when we cry, makes the throat muscles act
just as if we were vomiting, and as the action is an unnatural one,
when the ring or wave reaches the top of the throat, we feel the lump
or ball as we call it. We feel the lump because the throat has been
made to go through the motion of eliminating something in an unnatural
way, just as your arm will hurt if you pretend to have a ball or a
stone in it, and in throwing the imaginary ball or stone, you put the
same force into your movements as you would if you had an actual ball
or stone in your hand and were seeing how far you could throw it.
Why Do We Stop Growing?
We eventually stop growing because certain of the cells of the body
lose their ability of increasing in size and producing other cells. It
is one of the marvels of the construction of the human body that this
is so and one of the wisest provisions also. At first the cells of the
body crave lots of food and increase in size, divide and then the parts
go on growing until they become of a certain size, when they again
divide and each part goes on growing, etc., and thus we grow. A growing
boy needs more fond than a mature man, because he needs some of it to
grow with, while the man only has to keep what growth he has going, i.
e., alive.
We say this limit of growth is a wise provision of nature because if
there were no limit to the size we might become, we would not know how
large to build houses, barns, etc., or else we would have to build them
so large to start with that we would be lost in them for a long time.
We would constantly be forced to change these things and there would
be no basis to reckon from. Dogs might be as big as elephants and then
they would be of no use to us, or of what use would a dog as big as an
elephant be to a boy of five years. You see it would not do at all to
have this rule changed.
Why Do We Grow Aged?
We age directly in accordance with the lives we lead. You can bend
a wire back and forth a number of times at the same point without
breaking it, but eventually it will break. Just so with the human body.
You can use each part of it for its own purposes a number of times, but
eventually the break will come. Or, you can fail to make a part of it
perform its regular functions, and it will die--the break will come.
The human body is the most wonderful machine in the world, but even it
will eventually wear out. Every time you move your arm, leg or some
other part of your body, you destroy some tissues. The body replenishes
and builds up those tissues again for a certain time. When you bend a
joint in your body, the body oils the joint naturally, but as you grow
older, or rather, as you use the different parts of your body more and
more, it brings nearer always the time, when the body cannot, of its
own accord, build up again the tissues you have destroyed. That is why
some people become very old at forty and others are still comparatively
young at seventy. It requires a great deal of care and attention and
the elimination of all abuse of the body to keep us young when we
are old. The use of drink, lack of sufficient sleep and other abuses
prevent the body from restoring the tissues which have been destroyed.
Worry and sorrow age us very rapidly, because these things affect the
nerves. If the nerves are not quiet we cannot get any rest and without
rest we grow old very rapidly.
What Causes Wrinkles?
Wrinkles come to us in several ways. An easy way to cause wrinkles is
to scowl and frown and get into the habit of doing this. When you scowl
or frown you pucker up the skin on your forehead into wrinkles and if
you continue the habit the skin on your forehead makes the wrinkles
permanent. You have given your skin the wrinkle habit. This acts just
the same way as your arm would, if you tied it up in a sling and held
it close to your side for a very long time--a number of weeks. When you
took the sling off you would find your arm useless--a dead arm. It had
developed the habit of doing nothing.
In old people, however, wrinkles come more naturally. There it is the
case of the skin not receiving the proper nourishment and attention to
keep the circulation of the blood right. When people become old they
are apt to lose the fat which has accumulated under their skins. If
they had taken just the right amount of exercise all of their lives and
kept their circulation perfect in all parts of the body, there would
have been no fat there. But when the fat accumulates, it makes the
skin grow larger, and then when the fat disappears and people get thin
again, the skin is too large and makes the wrinkles.
Does Thunder Sour Milk?
Milk will sour in any kind of warm and moist temperature and, because
just before and during a thunderstorm the air is generally quite warm
and moist, it is only natural that it should turn sour. It is wrong,
however, to say or think that thunder makes milk sour. Thunder is only
a noise and noise cannot do anything but make itself heard. The fact
that it is generally warm and moist, however, when it thunders, coupled
with the fact that these conditions of the air sour milk very rapidly,
have led people to connect the two in their minds and caused them to
fall into the error of believing that the thunder is responsible for
the change in the milk.
What Makes the Rings in the Water When I Throw a Stone Into It?
Every movement has a beginning. When a movement on the earth is once
started it keeps on going until something stops it. If nothing stops it
it will go on forever.
When you shout you start air waves going in every direction, which
keeps on going until stopped by something which has the power to break
up their waves.
When you throw a stone into the ocean you start a series of ripples
or waves which spread out in every direction and if you dropped your
stone into the exact middle of the ocean--half way from each side--in
a perfectly calm sea undisturbed by other forces, your ring of ripples
would go on getting larger until it landed on the beach or shore on
each side of the ocean at the exactly the same time and there the beach
or shore would stop it.
The original ring of ripples is caused by the fact that when you drop
a stone into the water it disturbs the water where it goes in and
the water moves away from the stone to the sides, and as the stone
goes down, over and up above it, and the whole body of the water is
disturbed in such a way that makes the ripple appear on the surface and
spread out in every direction. As the stone goes down into the water
further and further the disturbance is repeated and ring after ring
appears on the surface.
Of course there are many disturbances in the water at all times. Many
things may happen to break up your little ring of ripples before they
touch the sides of the ocean--a ship--a fish--the wind--or one of many
other things, and because this is true you would have difficulty in
sending the waves made by your little pebble across the ocean, but you
can take a dishpan from the kitchen and after filling it with water
drop pebbles into it as nearly the middle as possible, and you will see
the ripples or waves your pebble makes spread out from the point where
the pebble entered the water in all directions.
Why Are There Many Languages?
Different languages developed in different parts of the world
because there was no inter-communication between people in different
communities, and each was really developing a language for itself.
In doing so they developed their language without knowing that other
communities were working out the same problems for themselves. So
they first developed their own sign and gesture language and later
on their word or sound language and kept on using it. While they may
thus have developed the use of some of the same signs and sounds or
combination of sounds to express one thing perfectly understandable to
themselves, these sounds or combinations of sounds might mean something
entirely different to another community, where that particular sound or
combination of sounds may have been hit upon to mean something entirely
different.
Of course, not all languages were developed in this way. There are,
you know, a great many languages used in the world. Some of them are
offshoots of others, where part of a community moved to another part of
the world, taking their language with them, but developing it further
along new lines, and using new combinations of sounds for new words.
Then also, there are many words which mean the same thing in different
languages and are spoken with practically the same sounds. This is due
to the movement of people from one nation to another and bringing their
own words with them, so to speak. In many instances a stranger would
come to another nation, and use his own word for expressing a certain
thing and that would eventually be taken up and used as a better word,
and the old word dropped. It is strange that this should be true, but
this accounts for the fact that many words are the same in sound and
meaning in numerous languages.
What Makes a Match Light When We Strike It?
The match lights when we rub it along a rough substance, because the
rubbing produces sufficient heat on the end of the match to set fire
to the head, as we call it, which is made of chemicals that light more
easily than the stick of wood, which is the rest of the match. The fire
thus started is hot enough and burns long enough to set fire to the
wooden part of the match.
To explain this more fully, let me say this. Rub your finger quickly
along your coat sleeve or along the seat of your trousers, long a
favorite place for men to strike matches, pretending that your finger
is a match. You find the end of your finger becomes warm, don’t you?
Not warm enough to set your finger on fire, of course, but if you had
the same combination of chemicals on the end of your finger that there
is on the match, you would set the chemicals afire and this would burn
your finger, just as it sets fire to the wooden part of the match.
It took a great many years to discover the combination of chemicals of
which the head of the match is made. Before that discovery was made it
was far from easy to light the light in the evening as it is now. It
must have been a serious thing to let the fire go out in the furnace in
those days.
What Makes the Kettle Whistle?
The kettle whistles only when the water boils and the steam or gas
which is the form the water turns into when boiling is trying to
escape through the spout of the kettle. You see, when the water starts
boiling, the inside of the kettle is at once filled with steam and more
is coming out of the water all the time. This steam must get out some
way, so it rushes for the spout of the kettle, and because so much of
it is trying to get out of a comparatively small opening at once there
is quite a pressure and this results in making the whistle out of the
spout of the kettle. It is just the same process as when you whistle
yourself. To whistle you fill your mouth with air and force it out
through your lips, which you have closed excepting for a small opening,
by the pressure you can bring to bear with the roof and sides of your
mouth, and if you have learned to make your lips into the proper shape
and apply the pressure steadily you can sound a very long note and make
different notes by making the opening in your lips large or small. The
kettle spout has only one size of opening so the sound is practically
the same at all times though louder at sometimes than at others. This
is caused by the varying pressure at which the steam in the kettle is
being forced out.
What Makes the Water From a Fountain Shoot Into the Air?
The water from the fountain shoots into the air because water anywhere
will run down if given a chance. To produce a fountain you must have
a source of water supply for the fountain which is higher than the
openings of the fountain out of which the water shoots. The water comes
out of the holes in the fountain for the same reason that it comes out
of the faucet in the kitchen or bath room. In the latter case the water
comes from the waterworks reservoir in which the level of the water is
much higher than the opening in the faucet in your home. Being higher
the water in the reservoir is trying to get away through the pipes all
the time and all the pipes leading from the reservoir are full of this
water trying to get away. Just as soon as you turn the valve in the
faucet the water comes out and runs down into the bowl.
If you were to turn the opening of the faucet up instead of down as
it is, the water would shoot up instead of down. Not very much, it
is true, but it would act much like the water from the fountain. The
reason it does not shoot up high in the air like a fountain is because
the opening in the faucet is the same size as the opening in the
little pipe which leads the water from the street into the house. If
you would turn the opening of the faucet up and attach to it a pipe
which made the opening much smaller (the size of the opening in the
fountains), you would see the water shoot into the air just as it does
from the fountain. When you reduce the size of the opening you increase
the pressure of the water coming from the pipes in proportion to the
reduction you have made in the size of the opening.
Water from the fountain will not, however, shoot as high as the level
of the water in the reservoir because, as soon as it leaves the pipes,
it encounters the pressure of the air outside the pipes and the law of
gravitation which pulls all things toward the center of the earth.
It is not natural for water to shoot into the air as it does in a
fountain. The only way water can go naturally is down, and it only goes
up a little way from a fountain because of the pressure of the water in
the pipes behind the openings in the pipes in the fountain.
What Keeps a Balloon Up?
A balloon stays up in the air, because of the air in it, together with
the weight of the balloon, is less than an equal bulk of the air in
which it floats.
In former days of ballooning the balloons were filled with hot air and
were then found to rise and stay up until the air inside of the balloon
became of the same temperature as that in which it floated. When this
stage was reached, the balloon itself would fall because the material
of which it was made was denser than air.
Today balloonists fill their balloons with gas which is lighter than
air, even when as cool as the air in which they rise and are thus able
to stay up a long time.
You, of course, have seen many of the red, white and blue paper
balloons which are sent up on the Fourth of July. You will remember
that father, or whoever it is that is sending them up, lights the
oil-soaked knot of cloth that is attached to the balloon immediately
below the opening at the bottom. He first lights this and then holds
the balloon for a time with his hands.
Soon, however, you will remember that the balloon starts upward with
father still holding it. This is because the air inside the balloon
is becoming heated. You will notice also that at first he has to hold
out the sides of the top of the balloon with his hands or has some
one help him do this, but that even so the balloon does not stand out
round and full as it should. When the balloon starts to rise, however,
you will notice that it is round and full. This is because the air in
the balloon has become heated and is expanding. Soon the balloon is
tugging to get away and father lets go and it rises and sails away with
the wind. As long as the fire below it burns, and if the wind does not
upset it so as to make the paper part catch fire, the balloon will stay
up; but, when the fire burns out, the balloon will come down.
The balloon merely rises because the air inside, and held there by the
covering of the balloon, is warmer air and lighter than the air on the
outside.
Why Did People of Long Ago Live Longer Than We Do Now?
When reading of people who lived long years ago and especially when
reading about the length of their lives, we are told that in the old
days people lived longer than they do now. Some of the early historical
records speak of single individuals who lived hundreds of years. There
is great doubt as to whether these statements are founded on fact. In
thinking about this we must first take into consideration that these
records of long ages were recorded at a time when man had no accurate
ideas of the actual passage of long periods of time such as a year.
They did not have our calendar as a basis for figuring at all. Learned
men now tell us that the actual age of men who lived at the time these
records of great ages were recorded probably lived shorter lives
than we do now, and that what they record as a period of one year was
probably a much shorter period than one year.
It is true beyond the question of a doubt that the people of today live
longer on the average than people who lived ten, twenty or more years
ago.
In other words, the average period of life has increased steadily.
This is due to the fact that we have taken great care of our bodies;
have improved the conditions in which we live, and made them more
sanitary; have learned to fight and check and eradicate diseases, which
only a few years ago we could not prevent people dying of when they
once contracted them, and we know from the records which we keep that
actually people live longer on the average today than only a few years
ago, and it is safe to say that they live longer now on the average
than at any time in the world’s history.
Is There a Reason for Everything?
The world is so constructed that there must be a reason or cause for
everything. There are so many forces in the world that man has not yet
been able to locate the original cause of every one of them. Concerning
other things, he sees the effects without having any knowledge of the
forces which are their cause. Other things he has never even bothered
to inquire about, but simply takes them for granted. But every force,
which means, of course, everything in the world, must have had a
beginning and therefore something or a combination of things must have
caused it to begin, and the thing or things that caused it to be is the
reason for its being. Every little while someone makes a discovery of
some new force, and then we suddenly realize that this force has been
in existence all the time although not known to man, and we discover
through this the reason for many other things being as they are.
The other thing or side of the question is also true. We cannot have
a cause without an effect. You cannot do anything without causing
something to happen and producing an effect on one or more other
objects either animate or inanimate. You cannot move your hand without
creating some disturbance in the air. When you make a noise, low or
loud, you produce sound waves. When you burn a stick of wood, you
create smoke, ashes and gases of various kinds. You change the whole
nature of what was the piece of wood, and yet no particle of what made
the stick of wood is ever destroyed or lost, but appears in some other
thing in the air or on or in the earth.
What Makes an Echo?
An echo is caused when the waves of air which you create when you shout
are thrown back again when they are stopped by something they encounter
and are turned back without changing their shape. Any kind of a sound
wave will make an echo in this way.
You see, you can have no sound of any kind without sound waves. You
could not make a sound if there were no air. Now, when you shout, you
start a series of sound waves that go out from you in every direction
and they spread away from you in circles just like the rings of ripples
that are caused when you drop a stone into a pool of water. You can
prove this to yourself easily by having one, two, three or more of your
friends stand around you in a large circle. You can place them as far
away from you as your shout can be heard if you wish. When you shout,
each of your friends will hear the shout at the same time, provided, of
course, they are at equal distances from you.
Sometimes these sound waves as they go away from you in circles strike
objects that turn the waves back unbroken just as they came to them.
The waves will bounce back just like a rubber ball from a wall against
which it has been thrown and this is the echo. However, some things
that the sound waves strike break up these waves entirely and others
partially.
No doubt you have sometimes noticed when you shout you hear a distinct
echo and that at other times, standing in the same place, you cannot
hear any echo, although you shout in the same way. This is explained by
the fact that at times conditions of the air are such that no echo is
produced while at other times a perfect echo results.
What is a Whispering Gallery?
The possibilities of an echo have to be taken into account by the
architects and builders of all public buildings, such as theaters,
halls and churches, where anyone is to speak or entertain others.
Unless they are very careful the walls and ceilings may be so arranged
that when any one sings or speaks in the room, there is such an echo
that it interferes with the music or speaking. It sometimes happens
also that through some peculiarity in which the walls and ceiling of
a building are constructed there will be certain places in the room
where an echo can be heard, even a whisper, and which cannot be heard
in other parts of the room at all. This is likely to occur in rooms
where there is a dome-shaped ceiling. There will be certain spots in
the room hundreds of feet apart, where if you stand on one spot and
another person is on another definite spot clear across the room, the
tiniest whisper can be heard, while the people in between cannot hear
at all. This is called a whispering gallery. Of course, loud talking
would produce the same effect. A whispering gallery is a gallery with
an echo which can be heard from certain positions. There are a number
of famous whispering galleries of the world. In the room beneath the
great dome of our Capitol at Washington is an almost perfect whispering
gallery. There are quite a number of points at which you can stand and
hear the whispers across the room which is more than a hundred feet.
These whispering galleries come accidentally, of course. It would be
difficult to deliberately construct a building in such a way as to
produce a whispering gallery.
Why Do We Get a Bump Instead of a Dent When We Knock Our Heads?
When you knock your head against a sharp corner, or if some one hits
you on the head with anything with a sharp edge, you do receive a dent
in your head, but it does not last. In other words, the head has one of
the qualities of a rubber ball. You can press your finger against the
sides of the rubber ball and push it in, but when you take your finger
off the ball resumes its shape. Just so with your head--it resumes its
shape after a blow.
After doing this, however, a bump or lump is formed. I will endeavor to
tell you how the bump is formed or rather what causes it to form. You
cannot knock your head against anything that is harder than your head
without causing some injury to the parts which received the bump. Now,
what happens then is just what happens to any other part of your body
when it is injured whether as a result of a bump, a cut or a bee or
mosquito sting.
As soon as the injury occurs the brain starts the “repair crew” to
work. The result is that first a great supply of blood is rushed to the
injured part with the result that the blood vessels are filled up and
extended with blood. Certain parts of the blood cells find their way
through the walls of the blood vessels at the part of the injury and
other fluids from the body are piled up there, so to speak, to form a
congestion. This “piling up or congestion” distends the skin and raises
the bump. On the head where the layer of muscular structure is thinner
and where there is less space between the bones of the skull and the
outside skin, the bump will be larger and more noticeable, because a
good deal of blood and other fluids are piled up in a comparatively
small space, and so the skin gets pushed out further to accommodate
this great congestion, whereas in other parts of the body the bump may
be quite as large but not so noticeable.
[Illustration: HOW MEN GO DOWN TO THE BOTTOM OF THE SEA