Happy Holidays

“ . . . and the glory of the Lord

shone round about them.”

May Christmas joys

and happiness

Fill your home

with cheer,

And Christmas peace

be in your heart

Through all

the coming year.

Visual source:  peopix

Germs

Men once believed that evil spirits made people sick.  Today we know that infectious diseases are caused by tiny organisms commonly called germs.

Three common kinds of germs are bacteria, viruses, and protozoa

Bacteria germs are one-celled plants that can be seen only through a microscope.  They cause many diseases, including pneumonia, scarlet fever and whooping cough.

Viruses are tiny organisms.  They are even smaller than bacteria.  Virus germs cause such diseases as mumps, measles, chicken pox and the common cold.

Protozoa are tiny one-celled animals.  Some kinds cause malaria and sleeping sickness.

The human body contains substances that germs can eat.  Germs invade the body through the nose, mouth, or a scratch in the skin.

Some germs causes an illness by destroying the tissue they live in.  Others produce poisons that can make us sick.

Visual source:  superstock

Clouds

Pluffy dark clouds and fluffy white clouds—all clouds are made of the same thing.  They are made mostly of tiny droplets of water drifting about on currents of air.  Water to make clouds comes from oceans, lakes and streams.

Everywhere water is continually evaporating into the air in the form of an invisible gas called water vapor.  Often the water vapor is carried upward by currents of warm, rising air.

As the moist air rises it cools.  As it cools, some of the water vapor condenses, or changes back to liquid water, in the form of tiny droplets, like the ones you moist breath makes when it hits the cold air on a winter day.

Many millions of these droplets, too small to fall, cluster together and make up the clouds in the sky.

Sometimes a cloud looks fluffy and white because the sun is shining through it.  Storm clouds may look dark and gray because they are too thick to let much sunlight through.

Visual source:  reefed

When we read of high mountains in books, we may wonder how the height of a mountain is actually measured.  Most of our figures for mountain heights were obtained with an altimeter.

This is a kind of barometer that uses air pressure to measure altitude, or height above sea level.  Altimeters give quick and easy readings.

For more accurate readings, surveyors use a special instrument called a transit, and mathematics.

Bu sighting a mountain peak through his transit, the surveyor finds the angle between an imaginary level line and the line of sight to the mountain peak.  By measuring the angles he can tell us how high the mountain is without actually climbing it.

Even with this method it is not easy to measure exactly how tall a mountain really is.

As far as anyone knows the very highest mountain land is Mt. Everest in the Himalayas.  It is 29,028 feet above sea level—over 5 miles high.

Visual source:  aviso.oceanobs

Fiber Glass

Fiber glass is made of very fine, flexible threads of glass, which can be spun and woven into cloth or used in many other ways.

Fiber glass is made from sand and other materials used to make ordinary glass.

The glass-maker first melts the glass materials and forms them into small glass marbles.  He then melts the glass marbles in a special electric furnace.

The melted glass runs down through tiny holes in the bottom of the furnace.  The hot strands are gathered on a spinning drum that stretches them into long, thin fibers and winds them on bobbins, like threads on spools.

In making fiber glass, a fiber nearly 90 miles long can be drawn from one marbles less than one inch wide!

The thin glass fibers do not crack or splinter, as you might think.

This is because the fibers are spun so fine that they become flexible, and may look and feel like silk.

Visual source:  easybizchina

Stained-Glass Window

In a church you may see a windows that look like a big jigsaw puzzles made of many pieces of colored glass held together with strips of lead.  The windows are called stained glass windows. To make such a window, the artist makes a big drawing on paper of the picture that he wants to put in the window. 

This shows each piece of glass and its color.  He then cuts pieces of colored glass to fit the drawing.  After he paints designs on the pieces of glass, they are baked in a furnace so that the paint becomes part of the glass.  Then the artist puts strips of lead between the pieces of colored glass to hold them together. 

Long ago the stained-glass windows in churches were like storybook pictures that told the story of religion.  Parents taught their children Bible stories from the stained-glass windows.  These were also the picture books of those who could not read. – Johnny Wonder

Visual source:  antiquechurchstainedglass