How did museums start?

Museum

Museum as we know them today grew out of the private collections started by wealthy people during the middle ages.

Where could you go to see an Egyptian mummy or the paintings of great artists?  Where could you see the bones of dinosaur?  The answer is “a museum.”

Just you may collect stamps or coins, museums are places that collect and display valuable art works, stuffed animals and many other interesting historical and scientific objects.

The first museums were founded in ancient Egypt.  They were usually places where art, music and the sciences were studied.  Museums as we know them did not develop until many centuries later.

They grew out of the private collections of works of art and other treasures started by wealthy people during the Middle Ages.  Today there are many different kinds of museums to visit.  Art museums, for example, collect and show paintings, statues and other masterpieces of art.

And you can see model dinosaurs in museums of natural history.-Dick Rogers

How does a siren work?

Siren

A siren is a kind of whistle which makes a loud noise as air is blown through holes in a spinning cylinder or disk.  It is a wailing noise

When a fire truck roars through the streets, its loud siren warms people to get out of the way.  An ordinary air siren has two cylinders, one inside the other.  The cylinder contain a number of holes.

When the fireman presses the button, an electric motor spins the inner cylinder and air is pushed through the holes.

When the holes in the inner cylinder are lined up with the holes in the outer cylinder, puffs of air escape and cause vibrations.  When the vibrating air (sound waves) reach our ears,  you hear the familiar ooooooOOOOOOEEEEEEeeeeee noise of the siren.

The faster the inner cylinder spins, the greater number of puffs of air, and the louder the siren.  A newer kind of siren makes its wailing sound electronically.  It does not have a moving parts like the older types. – Dick Rogers

What is parchment?

Parchment

Parchment is the dried skin of goats, sheep or other animals, treated so that it can be written on.

If you had lived long ago, in medieval days, you might have read books whose pages were made of animal skins instead of paper.

The first books made of pages bound together in a cover were made of parchment.  This is a king of material made from the skin of goats, sheep, and other animals.

Because parchment is expensive to make, the parchment on which a book was written was often considered more valuable than its content.  Frequently the ink was erased so that the parchment could be reused.

By the 1500s, paper had replaced parchment for all but the most formal documents.  The important-looking paper on which the diploma you get when you graduate from school is usually printed is called “parchment paper.”

Parchment paper is a kind of paper that is treated to look almost like real parchment, it lasts fro many years, but it is not as expensive as parchment.-Dick Rogers

How is nylon made?

Nylon

Nylon is a product of a chemical process in which carbon, nitrogen, oxygen and hydrogen are united to form a strong, tough material.

Nylon is a strong, long-lasting synthetic material.  Its uses range from such things as shear hosiery and fishing lines to toothbrush bristles and molded parts for machinery.

Nylon is made from common elements obtained from coal (carbon) and air (oxygen and nitrogen) and water (hydrogen).  These elements are heated, mixed and treated to such a way that they are changed into a substance called “nylon salt.”  

The nylon salt becomes a thick, gooey liquid when it is heated.  The melted nylon is spread out into a thin sheet to cool.  When hard, the sheet is cut into chips.  The chips are then melted and manufactured into final products.

To make yarn for weaving stockings and fabrics for clothes, the melted nylon is pushed through time notes in a metal plate.  Several threads of nylon are then twisted together into a single yarn and then stretched to make the nylon strong.–Dick Rogers

What is a doctorate degree?

Doctorate Degree

A doctorate degree is the highest degree awarded to a person by a college or university.

In the United States, a student who graduates after four years of study in a college or university normally receives a “bachelor’s degree” and usually specializes in a field of study called his major subject.

Some students begin work in their new professions after earning a bachelor’s degree.

Many do not stop their studies at this point, but go on for graduate studies that lead to a highest master’s degree, and then to a doctor’s degree to practice in special professions such as medicine, dentistry, law, or the field of education.

Degrees are awarded (conferred) at a ceremony called “commencement” – a term that means the beginning of a career outside academic surroundings.  A person on whom a college or university has conferred the doctorate is properly addressed as Doctor (abbreviated “Dr.”).–Dick Rogers

What is the difference between a lake and a pond?

Lake

Generally, a pond is described as a small body of still water without an outlet.  Lakes are usually much larger and deeper and often are fed by rivers and streams.  Generally, lakes differ from ponds in size.

A lake is commonly descried as a large body of water with land all around it.

A pond is usually smaller than a lake.  It is a quiet pool of water so shallow that rooted plants often grow completely across it and the bottom is usually covered with mud.

The cool water in a lake is often too deep for plants to grow except around the shore.  What people know as a pond or a lake, however, may differ from one place to another.

Pond

In some places, for example, a pond may be called a marsh.  And some large bodies of water commonly known as seas are really lakes, such as the Caspian Sea and the Dead Sea.

The “bowl” that holds a lake or pond is called the basin.  The basins of ponds and lakes may get their water from rain or be filled with water that flows into them from rivers, streams, or sometimes even from underground springs.–Dick Rogers

What makes a railroad crossing signal go on?

Train crossing signals are worked automatically by electricity made to flow when the train’s wheels touch certain sets of rails near the crossing.  People walking or riding need to be warned at an approaching train when they are about to cross the tacks on the highway.

Railroad Crossing Signal

Safety gates may close.  Electrically operated waving arms and flashing red sights accompanied by the ringing of a crossing bell can also warn of an approaching train.

When you see a train speeding down the track, you may wonder how the signals know it is coming.

The safety signals are operated automatically by an electric current that flows through special sets of rails near the crossing.  When the train’s  metal wheels touch the rails, they close the electric circuit. Causing the safety gate to close, the red lights to flash and the crossing bell to ring.

When the train is safety through the railroad crossing the wheels touch a second set of electrified rails on the other side, which turn the signals off and open the safety gate for the traffic.–Dick Rogers

What is the biggest desert?

Sahara Desert

The Sahara desert of North Africa is the Largest desert in the world.  It is nearly as big as the whole united states.

Almost as large as the whole United States, the Sahara stretches across the northern part of Africa from the Atlantic Ocean to the Red Sea.  

The Sahara desert is a vast, sun baked land of flat, rocky plains, shifting sands and rocky uplands.  A burning sun and scorching winds make it the hottest region in the world.  On summer days, the temperature may research 130 degrees F.  

Scattered through the Sahara there are oases, places where a spring or well provides enough water for date palms and other crops.  Only one river, the Nile, runs across the desert.  

The Sahara people wear long robes and turbans wound around the head and neck for protection against the hot sun and stinging sandstorms.  Camels were once the only means of transport across the Sahara.  Nowadays, buses and trucks cross many of the Sahara’s routes.–Dick Rogers

What do we mean by Latin America?

Latin America

We often use the name “Latin America” when speaking of countries located South of the United States.  It  comes from the fact that these countries were settled largely by the Spanish and Portuguese, and  as a result, have many of the Latin Cultural traditions.

The term includes Mexico, Central America, South America, and most of the West Indies.

The name Latin America comes from the fact that almost Portuguese and French settlers who spoke languages that grew out of Latin – spoken by the ancient Romans.

As a result, most people speak one of those languages.  Their religion, arts and customs came largely from these southern European countries.

Because of this “Latin culture,” the people are often called Latin Americans and the countries in which they lie are collectively called Latin America.

Not all people like to use the term “Latin America.” Other names that are sometimes used include Spanish America, Indo-America and Ibero-America.–Dick Rogers

What Is Oil Shale?

Oil Shale

Oil shale is a kind of rock that contains kerogen, a waxy substance that gives off liquid when heated.  Not all oil comes from oil wells that bring oil up from underground pools.

Much of the world’s supply of oil is  found in a kind of rocks formed of tightly packed clay, mud and slit.  This rocks is called oil shale.

Actually, this shale does not contain oil. It contains “kerogen” a  waxy material which, when heated, gives off a liquid  oil.

To get the oil from the kerogen  in the oil shale, the shale “ore” is mined and crushed.  Then  it is heated  in a furnace called  a retort. One  ton  of oil  shale  may  yield from  10  to 50- or-more gallons  of  crude oil.

When it  has been  refined, the oil can be separated  into gasoline and  other petroleum products, just as oil from  oil  from oil wells  is separated.

Shale oil is not widely used because it  is expensive to make.  But as the world ‘s supply of oil diminishes, oil shale may someday provide an important source of oil for all of our machinery.–Dick Rogers

Why do we say A.M. and P.M. when telling time?

The  letters A.M (ante meridian) P.M (post meridian) tell us  what part of the day it is on a 12 hour clock. 

As we all know, there are 24 hours in a day but only 12 hour numbers on a clock.  This is because in  most  countries the hours of the day are usually divided into two parts  for  timekeeping..

We call the  first  part  of the day  a.m. the second part p.m.

The  first clued clocks did  not keep  good time.  They had to be set every  day at noon, when the  sun  was at the  meridian, or the  highest point in the sky.

From  this we began to call the morning  part of the day a.m., meaning ”ante meridian.” or before noon.  P.M. means “post meridian” or after noon.

If every  town set its  clocks  by the sun today, few  places would  be on  the  same time.  When it is noon  in  one town, it is not yet noon in a town a few miles east.  For this reason. the world is divided into time zones.   All the clocks in a time zone are set  the same time.-Dick Rogers

How Do Hearing Aids Work?

Modern hearing aids work much like miniature telephones.  They  have microphones to pick up sound and  amplifiers that increase the loudness in the ear  of the wearer.

Perhaps  the hearing of  someone  you know is not as good as it was when  he was  younger and he must now wear  a hearing aid.

Hearing Aid

A  hearing aid is a sound  amplifier -  a device that increases the loudness of  sounds in the ear of the wearer.

The earliest  hearing   aid  was the ear  trumpet. This was  a  trumpet- shaped  instrument.  Its small end was  placed  to the ear. It simply  gathered in sound and funneled  it into the ear.  Today people who are hard-of hearing use  small transistor hearing aids instead of ear trumpets.

Modern hearing  aids are  essentially  small battery-powered  telephones.  They have  microphones to pick up sound and amplifiers to make sounds  louder.

A  button- sized  receiver fits in the ear or behind it, depending on the  type of hearing defect, and sends sound  vibrations to the hearing center.  Sometimes, hearing aids are so  tiny  that you hardly notice them.–Dick Rogers

Who invented the piano?

Piano

The piano was invented  early  in  the 18th century by an  Italian harpsichord maker  named Bartolommeo Cristofori.  The piano is a stringed  instrument played  with a keyboard. 

The first piano was invented  early in the 18^th century by an Italian harpsichord maker named  Bartolommeo  Cristofori.  His invention  was designed to remedy  the harpsichord’s inability to play softly or loudly by the touch of the fingers. 

He called  his invention “gravicembalo  col piano  e  forte”(Italian  words meaning “harpsichord  with soft and  loud”) to show that, unlike the  harpsichord, it could be played both loud and soft with ease.  The name was shortened  to piano- forte and finally to piano.  The keyboard of a standard piano consists of 88 white and black keys.

Inside the piano  there are many wire strings stretched over a sounding board.  There are also wooden  hammer  covered  with  felt.  When  you  push down on a piano key, a hammer  strikers a set of strings.  The strings vibrate and  make the musical sound.–Dick Rogers

How Did The Stagecoach Get Its Name?

Stagecoach

Coaches that carried passengers became known as “stagecoaches” because they stopped to rest at stage stops along the way.

Until railroads appeared, early travelers in America made long-distance journeys either on horseback or in horse-drawn coaches, called “stagecoaches.”

Stops were made along the way at rest stations, or “stages,” for fresh horses and food for the passengers.  Thus the name of “stagecoach.”

Travel by stagecoach was often unsafe as well as uncomfortable.  The travelers faced the constant danger of robbery and Indian attack.  The stagecoaches bumped along the bumpy dirt roads day and night.

The passengers, grimy with dust in summer and shivering with cold in winter, tried to sleep on the hard seats.  A trip from Missouri to California took nearly three weeks.  Many of the finest stagecoaches were made at Concord, New Hampshire.  They were handmade and cost $1,500 each.

Concord coaches drawn by six horses bounced along at a brisk, 10 miles an hour. So well were the coaches built that many of the original coaches are still used in Western movies. – Dick Rogers

What is cement made of?

People often misuse the words cement and concrete.  For example a “cement sidewalk” is really made of concrete.

Cement is the fine, gray powder that is mixed with water, sand and crushed rock or gravel to make concrete.  The cement and water from a paste that hardens as it dries, and binds the sand and gravel together into the hard, rock-like mass we use in building tail skyscrapers, smooth sidewalks and large bridges and dams.

Cement

Cement is made from lime and other materials, such as silica, alumina, iron and gypsum.   The lime used to make cement comes mainly from a rock called limestone.

Cement is made by burning crushed limestone with the other materials.  The heat changes the mixture into a new material called “clinkers.”  The clinkers are then finely ground into the gray, powdery cement.  After this, it is ready for use in masking concrete.

Before the concrete is mixed, workmen must measure the proper amounts of sand, gravel and water with the cement to give it the proper strength.  When first mixed, the wet concrete, called a “batch,” can be poured into molds of almost any shape.  It quickly hardens into a solid mass as hard as natural stone. – Dick Rogers