In the dry finishing the cloth is finished with various kinds of
finishes desired, and it is steamed, brushed, sheared and pressed.
Another examination for any imperfections or defects follows; the cloth
is measured, packed and tagged and is ready for the market.
The difference between worsteds and woolens is principally that in the
threads or yarns from which worsteds are made the fibres of the wool
lie parallel, one to another, being made from combed wool, from which
the short fibres have been removed; and woolens are made from yarns in
which the fibres cross and are matted and intermixed. When finished
the effect of worsteds and woolens is materially different. Upon
examination it will be found that the worsted thread resembles a wire
in evenness, while the woolen thread is uneven and irregular.
A worsted fabric when finished has a clear, bright, well defined
pattern, seems close and firmly woven, and is of a pronounced dressy
effect; while woolen cloths are softer, they are more elastic, the
colors are more blended, the threads are not so easily distinguishable
and the general effect is duller.
Why Can’t We See in the Dark?
We cannot see in the dark because there is no light to see by. To
understand this we must first understand that when we see a thing, as
we generally say, we do not actually see the thing itself, but only the
light coming from it. But we have become so used to saying that we see
the thing itself that for all practical purposes we can accept that as
true, although it is not scientifically exact. Scientifically speaking,
we see that part of the sunlight or other light which is shining upon
it, which the object is able to reflect.
If there were no air about us we could not hear any sounds, no matter
how much disturbance people or things created, because it requires air
to cause the sound waves which produce sound, and air also to carry
the sound waves to our ears. In the same way, if there is no light
to produce light rays from any given object to our eyes, we can see
nothing. It requires light waves to produce the reflections of objects
to our eyes. Without light our eyes and their delicate organs are
useless. You cannot see yourself in a mirror when the quicksilver which
was once on the back of the glass has been removed, because there is
then nothing to reflect the light. We can only see things when there is
light enough about to reflect things to our eyes. When it is dark there
is no light, and that is the reason we cannot see anything in the dark.
Why Can Cats and Some Other Animals See in the Dark?
They cannot see in the real dark any more than human beings. These
animals can find their way in the dark and can see more than a human
being, because of one distinct difference in their eyes, which may for
them be considered an advantage. The pupils of their eyes can be made
much larger, and they can, therefore, let more light into their eyes
than people. The result is that when it is so dark that you cannot
see a thing and you decide it is really dark, the cat can still see,
because there is always a little more light left and she can open the
pupils of her eyes and make them larger, thus letting in more light,
and the little bit of light there is still left gets into her eyes and
she is able to see. But in a really dark room a cat could see no more
than you can. You see, our eyes open and shut more or less just like
those of the cat, according to the intensity of the light. When you go
out of the dark and shaded room into the bright sunlight and look at
the sun, you naturally squint your eyes without deliberately intending
to do so. This is nature’s way of preventing too much light getting
into your eyes at one time. Gradually the pupils of your eyes contract
and get smaller, until you can see, without squinting, anything in
the sunlight. If, then, you were to go right back into a dark or
shaded room, you would have to wait a moment or two before you could
see things distinctly in the room--until the pupils of your eyes had
dilated (become larger), so as to let in enough light to enable you to
see normally. The eye automatically enlarges and contracts the pupil of
the eye, to enable us to see distinctly in either light or less light
places.
Why Is It Difficult to Walk Straight with My Eyes Closed?
The reason we cannot do this always is because when we walk naturally
the steps taken by our right and left feet are not of equal length.
This difference in the length of the steps is due to the fact that our
legs are never exactly the same length. We think of them generally as
of the same length, but they are not, and this will be proven if you
measure them accurately. Now, then, the longer of the legs will always
take a longer step than the shorter one, and so, if our eyes are shut,
we walk in circles, unless we have something to guide us. When we
walk with our eyes open, we are able to overcome the tendency to walk
in circles, because our eyes help the brain to direct the legs on a
straight course. Another reason which affects the matter is that our
eyes are very necessary in keeping our bodies balanced on our feet, and
it is very difficult to learn to keep the body balanced with the eyes
closed. Now, when your eyes are closed and you attempt to walk in a
straight line your body balances from one side to the other, and this
fact, coupled with the first reason given, makes your course irregular.
But, say you, the man on the tight-rope has his eyes bandaged and he
walks a very straight line. Yes; but remember that he has a straight
tight-rope to guide him, and all he needs is to maintain his balance.
One can learn to walk in a straight line with the eyes closed, but it
takes a good deal of practice, as you will learn if you try.
Why Can’t We Sleep with Our Eyes Open?
We cannot sleep with our eyes open, because to be asleep involves
losing control of most of the functions of the body. When we sleep
the brain sleeps also. Perhaps it would be stated more clearly to say
that we cannot sleep while the part of the brain which controls our
activities is awake. There is a part of the brain which has the power
to open our eyes, i. e., lift the eyelids, and when that portion of the
brain ceases to exercise its power to keep the eyes open, they go shut.
Even when we are awake that part of our brain cannot keep our eyes
from winking, because there is another part of the brain which sees to
it that our eyes wink every so often. This is done for the purpose of
washing the eye-ball, and is the answer to another of your questions
which is given in another place in this book. When the engineer at the
electric light plant shuts off the power all the lights go out, and
when you go to sleep you automatically shut off the power that opens
your eyes, and the eyes are shut. The brain is asleep also, and if it
is not completely asleep, you are restless.
Why Do Our Eyes Sparkle When We Are Merry?
If you should watch very closely the eyes of a merry person when you
see them sparkle you would probably notice that the eyelids move up and
down more often under such conditions than ordinarily, and if you know
what moving the eyelids up and down in front of the pupil of the eye
does, you will have your answer.
Every time the eyelid comes down it releases a little tear, which
spreads over the eyeball and washes it clean and bright. It does this
every time the eyelid comes down. Now, there is something about being
merry which has the effect of making the eyelids dance up and down,
and thus, every time the lid comes down, the ball of the eye is washed
clean and bright, and gives it the appearance of sparkling, as we say.
Why Do We Laugh When Glad?
We laugh when glad because the things which make us laugh combine
together to rouse those parts of the body which are involved in a
good laugh to act in a certain harmony, and when this combination is
arranged in a certain way it produces a laugh. Certain things in the
world, whether they are funny, ludicrous, or other things that produce
the laughing effect, cause the brain to work certain muscles and
nerves in a combination that produces a laugh. The impression which
reaches the brain causes these muscles and nerves to act involuntarily
and the laugh comes. It works just like the keys of the piano. Some
combinations of notes produce sad sounds and other combinations produce
glad sounds, but the combination when once touched will always produce
the same sound. It is the impressions made on the brain which start the
proper combination, and it does this instantly. Just as a pin prick in
the arm will at once send a “hurt” message to the brain and cause the
brain to jerk the arm away, so a laugh-producing combination of sounds,
or things we see, or feel, sends an impression to the brain which at
once sends out the “laugh” order. Some things make some people laugh
while they do not affect others at all. That is because our brains are
not always the same in regard to recording impressions. Some things
impress some brains one way and others entirely in a different way or
not at all. You do not laugh so heartily the second time you hear a
funny story, because the impression the brain receives when the story
is told the second time is not so vivid.
Why Do I Laugh When Tickled?
Practically the same things happen when we are tickled, and explains
why you laugh when tickled. When some one tickles the bottom of your
feet or your ribs or another part of your body it produces, in most
cases, the same effect on the brain as the laugh-producing sound or
sight, and arouses the same combination of muscles and nerves to
activity. It is just like pushing the button of an electric bell. When
you push the button the contact produces the spark which sets the
machinery of the bell in motion and the bell rings and will continue
to ring as long as you keep your finger on the button, or until the
spark-producing power of the battery is gone. Then, as in the case
of the bell, you cease to laugh, because the spark that produced the
laugh combination is gone. That is why some things tickle some people
very much and do not affect others. Some are not so sensitive to the
laugh-producing combination as others. After the thing that tickles you
has been going on for some time you are not tickled into laughter any
more, because the impression on the brain ceases to be as strong.
Why Don’t I Laugh When I Tickle Myself?
Your mind tells you there is no need to laugh when you tickle yourself.
Your mind will not respond to the tickling sensation when it is aware
that the cause of the tickle is yourself. The reflex action of the mind
which causes laughter and squirming when some one else tickles you only
acts when it is not conscious of the cause.
The whole purpose of the sensitive organization of our skins is to
give us information and cause action which will enable us to protect
ourselves when any outside influence touches us. An injurious touch
causes shock and pain, and the harmless tickle arouses the laughing and
squirming sensation.
What Happens When We Laugh?
Laughter is what we call a reflex action. When something occurs to
make us laugh, whether it is something we see, or feel, or hear, it is
because certain sensory nerves receive an impression in one of three
ways, carry it to the nerve centre and the nerve centre then sends
the same impression along certain efferent nerves, which connect with
certain muscles or glands, and excite them to activity. The action is
practically the same as when you hold a light before a mirror. The
rays from the light strike the surface of the mirror and are reflected
back from the surface, lighting perhaps corners of the room, which the
direct rays from the light could not reach, all depending upon the
angle of reflection. Light will always reflect from a mirror that is
exposed to it.
Now, then, when you see, hear or feel anything that makes you laugh,
the sensory nerves have only to receive the impression to bring on
the explosion of laughter. Something touched the laugh nerves or the
laugh trigger that caused it to go off. You can prove that it is a
matter of impression entirely by noting that some people can listen
to a perfectly funny story, even when told by a clever performer, and
never crack a smile, while others burst into uncontrollable laughter,
and he who does not even smile may be listening even more intently than
the other--he may even be looking for a laugh. It all depends upon the
impression that is made upon the nerves. The muscles have the power
to express the state of gladness which is indicated by laughter when
certain impressions pass along the nerves which operate them, just as
they can be made to do other things when the proper cause for action is
shown them.
Why Do We Cry When Hurt?
We cry when we are hurt for the same reason that we laugh when we
are glad. The muscles and nerves, under the direction of the brain,
produce the cry just as the muscles and nerves produce laughter,
although they are probably, but not necessarily, a different set of
muscles and nerves.
When we are hurt in any part of our body or feelings the impression
does not affect us until it reaches the brain. Then instantly, of
course, the body and brain go to work to destroy the pain. The first
thing, of course, is to give a warning to other parts of the body that
there is a hurt, and our crying is a warning to other people that we
are hurt. That is probably the only good that crying does. It does not
remove the hurt--it only tells others of our troubles. We cry with the
lower part of the brain--the only portion of the brain which is active
in a little baby. This is why even a tiny baby can cry. Crying is the
only thing a baby can do to give warning of its distress or discomfort.
Later in life the upper part of the brain develops. This is the master
of the lower part. Therefore, we do not always cry when hurt as we grow
older, because the master brain sometimes tells the lower brain that to
cry will not help matters in the least, even though we are inclined to
cry. Sometimes the hurt or shock to older people is so great or sudden
that we cry out before the controlling part of the brain has had time
to get in its work of preventing the outcry, but we are able to stop
crying when the master brain again secures control.
Where Do Tears Come From?
Tears are not made only when we cry. They seem to come only when you
cry, because it is then that they spill over. A little part of you
is making tears all the time, and your eyes are constantly washing
themselves in them. You have often noticed how you wink every few
seconds? You have often tried to keep from winking--to see how long
you could keep from winking. Boys and girls often do that, and when
you keep from winking what seems a long time, you notice how your eyes
ache and feel very dry just before you have to let them wink, in spite
of how hard you try not to, and just when you think you are not going
to. I will tell you just what winking does for the eyes. All of the
time your eyes are open the front, or the part you see things with, is
exposed to the dust and dirt that fills the air at all times, although
we cannot always see the dust. The wind, too, is constantly making them
dry. But have you ever noticed that although you never wash the inside
of the front of the eye, or pupil, it is always clean? Well, it is
because your eye washes itself every time you wink. I will tell you how
this is done. Up above each eye, inside, of course, there is a little
gland called the tear-gland. This gland is busy all the time you are
awake making tears. As soon as the front of your eye becomes dry, or
if a particle of dust or anything else strikes it, the nerves you have
there tell the brain, and almost at once the eyelid comes down with a
tear inside of it, and so washes the front of your eye clean again. It
does its work perfectly and as often as necessary. There is always a
tear ready to be used in this way.
Where Do the Tears Go?
Let me show you. Look right down here at the inner corner of my eyelid,
where you will see a little hole. That is where the tears get out of
the eye, when they have washed your eyeball clean. Where do they go
then? Did you ever notice how soon after you cry you have to blow your
nose? The reason for that is that when the tears go through the little
hole they run down into the nose. This making of tears and winking
goes on all the time while you are awake, and after they wash your eye
off they go on out through this little hole. But when you cry you make
more tears come than you need, so many, in fact, that they cannot all
get away through this little hole, and as there is no place else for
them to go, and as there is no place to keep them inside the eye, they
simply spill themselves right over the edge of your lower eyelid and
run down your cheek.