Reach for the Sky

Reach for the Sky

The industrial world

Skycrapers are a product of the Industrial Revolution, which began in England in the eighteenth century. New inventions revolutionized the way people lived. Steam engines, and later electricity, made enough energy available to do many more times the work that people and animals had done before. A new method of smelting iron produced huge quantities at low prices. Other inventions gave builders steel, a material even stronger than iron. Cities grew an skyscrapers provided a solution to the problems of overcrowding because they take up little space on the ground. Skyscraper frames were first built with iron, then with steel. New engines powered elevators to hoist people to the top. The weight of a tall building can easily cause it to sink or lean, so the early skyscrapers were usually built on solid rock. This is why so many were built on Manhattan, a rocky island in New Your City.

Coalbrookdale Bridge

The world gained a new construction material when inexpensive iron was developed. In 1779, the English built Coalbrookdale bridge in Shrpshire, which was the first iron bridge to be constructed.

The first skyscraper was built in 1884 in the city of Chicago, Illinois. It was only ten-stories high.

Eiffel Tower

This iron and steel tower was built for the Paris Exposition of 1889. When radio was invented, the tower began its long career as an antenna. It carried the first transatlantic radio-telephone call.

Manhattan two towers skyscrapers. Photo by Elena.

The Tallest of Them All

For more than 4,500 years, the Great Pyramid of Khufu in Egypt was the tallest building in the world. Then the Eiffel Tower was built in France in 1889. In may parts of the world today, skyscrapers and towers continue to grow taller and taller. Some of the tallest building in history: St. Peter's Basilica, Italy 1612, 453 ft. Great Pyramid of Khufu, Egypt, 2700 BC, 479 ft. Eiffel Tower, France, 1889, 984 ft. Empire State Building, USA, 1931, 1,250 ft. Sears Tower, USA, 194, 1,453 fr. CN Tower, Canada, 1976, 1,804 ft.

Crown

The Art Deco style, a novelty of the 1930s, inspired the triangle-shaped windows. These are set within tiers of arches on the crown of many buildings.

Going Up

Steam engines powered the first elevators, which were used only for freight. The first passenger elevators were installed in 1857 after a way was found to stop them from falling if a cable broke. By 1889, they were powered by electric motors. The elevator doors of the Chrysler Building are decorated in the Art Deco style.

Life at the Top

Native Americans were some of the earliest construction workers on skyscrapers. They worked at great heights while standing only on 8-in wide steel beams.

Core

A strong frame is built inside the building for the elevators. This frame also helps the buidling resist the pushing and twisting forces of the winds.

Chrysler Building

Walter Chrysler built this 77-story skyscraper in New York City during the worldwide Depression of the 1930s. It provided much-needed employment for many construction workers. The building was the headquarters for his automobile empire and a monument to his success.

Early Civilizations

Early Civilizations

More than 5,000 years ago, a great civilization developed in Mesopotamia, the land between the Tigris and Euphrates rivers, then spread eastward along the north coast of the Indian Ocean. The Egyptian civilization developed beside the River Nile soon after. People traveled between the two areas and brought new ideas and inventions with them. Egypt had many workers and plenty of stone, and the Egyptians built huge pyramids and temples using simple tools and techniques. Because they did not have the wheel, 20 men pulled each stone to the pyramid on a wooden sled. Both stone and wood were scarce in Mesopotamia. The people there invented new materials such as bricks molded from clay and baked in an oven or dried by the sun. They then built wheeled carts to transport the bricks.

The Pyramids of Giza

These three pyramids were built more than 4,500 years ago as tombs for Egyptian pharaohs. The largest of the three, the Great Pyramid of Pharaoh Khufu, contains nearly two-and-a-half million stone blocks.

Temple for a God

The huge columns of Egyptian temples still stand like stone forests in the desert above the banks of the Nile. This complex at Karnak was built over a period of 1,200 years. A statue of a pharaoh and his daughter stands outside the temple.

Early Civilizations. Photo by Elena.

Did You Know?

Some Egyptian architects today are also building vaulted structures out of sun-dried bricks. The buildings stay cool and the materials do not damage the environment.

Steers and dragons

The symbols of the babylonian weather god Adad and of the city's protector, the god Marduk, decorate the Ishtar Gate.

Ishtar Gate

In the sixth century BC., king Neubuchadnezzar built a road called the Processional Way. This road led from his palace in the city of Babylon, the main city of Mesopotamia, to a ceremonial hail for New Year's celebrations. The Processional Way passed through the city's double wallsat the Ishtar Gate.

Parade of Lions

Every animal lining the walls of the Processional Way was brick, cast from special molds so that the bodies curved out from the wall. Each of the lions was made up of 46 specially molded and glazed bricks.

Glazed Bricks

The bricks on the walls were painted with a glasslike mixture then baked to produce glowing colors.

 Arched Vault

The passage through the gate was 13 ft wide, which was only possible because it was covered by an arch.

Inventing the Arch

A stone laid across an open space like a doorway is brittle and will break it a heavy weight is placed on it. To avoid this, the supports of ancient stone buildings were set close together. Mesopotamians invented the arch so they could build wide, open rooms. Bricks or small stones set in a curve from an arch, the weight of each stone puses it against the next until one pushes agains a thick wall, called a buttress. The buttress presses the stones together and holds the arch in place. A vault is a celling built with arches.

Early American Empires

Early American Empires

The oldest architectural monuments in the Americas are found in present-day Mexico and along the west coast of South America. Early civilizations there had neither iron tools not animals that could be trained to pull carts, yet the people constructed enormous stone buildings. The Omecs and later civilizations in Mexico such as the Toltecs and Aztecs lived in scattered farm villages. These peoples had one religion and their religious centers were cities of stone such as Teotihuacan, where temples stood on top of tall pyramids.

The peace-loving Mayan people lived in the rainforests of the Yucatan Peninsula in Mexico and they also built their religious centers of stone. In the fifteenth century, the Incas ruled an empire 2,480 miles (4,000 km) long in the Andes mountains of Peru. Their many towns were united by paved roads and a fast mail system. Incan stonemasons cut, polished and fitted stones together so tightly that a knife blade will not slide between them even today.

Stairway of goods

Two sides of the pyramid have steep stairs. A row of carved masks of Chac, the god of rain, line both sides of the staircase.

Pyramid of the Sun

This pyramid, built in the third century in Teothuacan, Mexico, stands on a high platform and is surrounded by volcanoes. Stone covers a core of dirt and lava carried to the site by thousands of workers over a period of 30 years. Aztecs lived there centuries after its Teotihuacan builders had disappeared. They believed this pyramid had been built by the gods themselves.

Palace of the governors in Uxmal, Mexico, is decorated with carved serpents and the Mayan rain god Chac. Religious leaders lived in its cool corbel-vaulted rooms.

A Mexican God. Photo by Elena.

Pyramid of the Magician

The Mayans built their pyramids in Uxmal, Mexico, in the ninth century. It has an unusual oval shape and two temples at the top. The peoples of Mexico built high platforms, or pyramids, for their temples so they would be closer to the gods in the heavens.

At the top

The temples on the pyramid are stone replicas of Mayan Thatched huts. Gifts were offered before statues of gods inside the corbel-vaulted rooms.

The Citadel

Offerings were placed on this Chac Mool, a god sculpted as a man tying on his back, which sits near an eleventh-century Toltec pyramid in Chichen Itza, Mexico. The pyramid has a steep staircase on each side and a temple at the top.

Corbeled Roofs

A building constructed of stone posts and horizontal beams will collapse if the beams have to support heavy walls or if the posts are not set close enough together. Stone doorways and stone roofs or vaults can be built with small stones called corbels. Each stone lies on top of the last stone and has one end sticking out over the opening. Once the stones or corbels from both sides of the opening meet at the top, stones placed on top of the roof will hold it in place.

Did You Know?

The Pyramid of the Magician encloses three older temples. In Mexico, a new pyramid and temple often encased an earlier one. A completely furnished temple ready for use was discovered within the Pyramid of the Sun.

Incan Ruines

Important religious ceremonies took place in Machu Piccu, an Incan town high in the Andes mountains of Peru. The plain stone walls of important Incan buildings were covered with plates of pure gold.

Place to Live

A Place to Live

People must have shelter to survive. They will die without protection from the sun, rain, wind and cold. Today, people can live in almost every part of the world because they have learned to build walls and to put a roof over their heads. For centuries, people had no tools to cut or move trees and large stones, so the first houses were built from materials that were hard rocks with sharp edges could cut trees and other rocks, and these became the first building tools. Many centuries later, people melted metals from rocks to make stronger, sharper tools. In places with little stone or wood, people made sun-dried bricks out of mud to build their houses. Some of the earliest cultures in history were the first to discover and use many of the basic building materials still used today.

Did you know?

The basic methods used to support the roofs of many great buildings were first developed in ancient villages to hold up the roofs of huts.

The Roof

A waterproof roof is made from grass by thatching. Bundles of swamp grass are tied to a wooden frame so that each bundle overlaps the ones next yo it and below it.

Stone Hut

Walls of stone shaped with tools surround clusters of houses in many ancient villages. Each house has several rooms and each room has its own dome. Some even have a second story. Smoke from fires used for cooking escapes through holes in the roof.

A perfect place to live. Photo by Elena.

Making Bricks

Sun-dried mud bricks were perhaps the first synthetic building material ever made. A mixture of mud and straw is pressed into molds then laid out in the sun to dry. The straw holds the bricks together so they do not crumble. As rain will dissolve sun-dried bricks, a coating of lime is added or a wide roof is built to protect the walls.

Beehive Hut

A hut on Dingle Peninsula in Ireland looks like a beehive. It was built centuries ago. It was built centuries ago by a monk who piled up small flat stones cleared from his fields. He stacked each circle of stones on top of the circle below and made each stone slope downwards slightly towards the outside, so rain could not get in (as well in the village of Haaran on the Turkish-Syrian border).

The Walls

A man in weaving mats from palm fronds or leaves, which will become the walls of his hut. Weaving stiffens the fronds.

South Pacific Woven Huts

On the Trobriand Island of Papua New Guinea, houses are still built from small trees cut with stone tools. The pieces of wood are tied together with vines to form the frame of each house. The island people use plant material to complete the house. Grass and leaves vend easily and people thought they seemed too weak to use for building until they discovered how hard it was to pull them apart.

War and Peace

Today and Tomorrow

War and Peace

Technological progress is faster in times of war. Each side tries to make weapons and machines that are bigger and better than those of the enemy. At the beginning of the First World War, for example, the typical flying speed of an airplane was 70 miles per hour. By the end of the war this speed had doubled. In the Second World War, the Germans introduced two inventions that later transformed flight – the turbojet, which became the basis of modern aircraft, and the ballistic missile, which took aviation from the skies into space.

Some wartime inventions, such as the tank, are only suited to war, but many have other uses. The antibiotic penicillin, which saves many lives, was invented in 1941 to cure the infected wounds of soldiers. It is impossible to say whether more good has come from wartime inventions than bad. But one thing is certain, many things were invented because of war.

Radio Detection and Ranging

In 1935, the scientist Robert Watson-Watt was asked by the British army to invent a radio death ray for warfare. Instead, he invented radio which detects enemy aircraft using radio waves.

Guided Missiles 

All modern strategic missiles and space rockets were developed from the work of a team of Second World War German scientists, who created more than 20 types of missiles. Air-to-air guided missiles, such as this one, are used for aerial combat. 

Red Floppy. Photo by Elena.

Armored Tank

The tank lurched onto First World War battlefields in 1916, thanks to the combined efforts of a number of inventors and British army officers. This modern United Nations tank has a swiveling gun turret and lookout post.

Modern Armor

Heavy steel armor plating was first used in America in 1862 to strengthen warships. Today's tanks are encased in lightweight but strong metal alloys, plastics and even ceramics.

Stealth Fighters

Difficult to detect because of their shape and a radar absorbent coating, F-117 fighter bombers are designed for precision attack. They were used by the United States in the Gulf War in 1991.

Lethal Weapons

Grenades have been around for more than 500 years. In the 1600s, French soldiers, called greanadiers, were trained specially as throwers. Plastic explosives, once unwrapped from their sausagelike skins, can be molded into position. They were used in military operations to shatter parts of bridges and buildings.

Caterpillar Tracks

In 1904, Benjamin Holt built a tractor that laid down its own track under the rear wheels to travel over mud. A continuous track enables it to break through fences and go over deepgullies.

Night Vision

Since the 1950s, scientists have been working on devices to make it possible for soldiers to fight in the dark. The night-vision goggles shown below are sensitive to low levels of light, such as reflected straight or moonlight. The goggle intensify this light and allow soldiers to see, move and shoot at night as well as they can during the day. In theory, 24-hour war is now possible.

Time-line

• 1861 : Sea Mine – USA
• 1862 : Machine Gun – Richard Gatling, USA.
• 1883: Automatic Machine Gun – Hiram Maxim, USA.
• 1902: Exploding Bullet – John Pomeroy, New Zealand.
• 1915: Sonar – Paul Langevin, France.
• 1944: V2 Rocket Bomb – Wernher von Braun and Walter Dornberger, Germany.
• 1945: Atomic Fission Bomb – Project Manhattan scientists, USA.
• 1952: Hydrogen Bomb, USA.
• 1984: Stun Gun, USA.
• 1985: Flashball Gun – François Richet, France.

War and Peace. Illustration by Elena.

Biotechnology

Biotechnology

We use biotechnology to alter living things. It gives us the power to create new animals, plants, foods, medicines, materials and even machines. People have used biotechnology for thousands of years to slowly breed new plants, animals and the microorganisms that make cheese, bread, beer, yogurt and wine.

In 1987, geneticist Truda Straede of Australia created spotted cats after breeding toroiseshell cats with Burmese and Abyssinian cats for ten years. Today, modern biotechnology could speed up this breeding process by altering the genetic material deep inside the cells. Scientists have already created bright blue carnations, and tomatoes that ripen on the vine without getting mushy. Biotechnology's potential is enormous. We can even use bacteria grown in laboratories to digest oil to clean up oil spills. The next hundred years will be an age of exciting ”bio-inventions”.

Spot the Difference

In the future, the spot-making genes from a leopard could be mixed in with the genes of a domestic cat to produce a spotted animal.

Killer Cotton

In 1992, an American company altered the genes in some cotton plants so that their leaves became poisonous to caterpillars but nothing else. This reduced the need for harmful insecticides.

Two cats, Jamaica. Photo by Elena.

Strange but True

In 1994, scientists in Australia invented a way of removing fleece from sheep without shearing. They injected sheep with a special hormone then wrapped them in lightweight hairnets. Three weeks later, the fleece could be peeled off the sheep by hand.

Transgenic Pigs

The heart of a pig is similar in shape and size to the human heart. People and pigs, however, have very different genes. Scientists in England have developed a virus that carries human genes into pigs. This makes it possible for the human body to accept the heart of a pig in a transplant.

Changing Genes

Every living cell has spiral-shaped deoxyribonucleic acid (DNA), discovered in 1953 by Francis Crick and James Watson at Cambridge in England. The DNA is made up of genes that control how the cell works. Biotechnhologists have learned how to alter the genes and change living cells.

• 6000 BC: Beer – Mesopotamia.
• 1000 BC: Cheese – Nomad tribes, Middle East.
•  1972: Oil-digesting microbes – Dr. Ananda M. Charkabarty, USA.
• 1975: Monoclonal Antibody – George Kohier and Cesar Milstein, England.
• 1984: Transgenic plant – University of Ghent, Belgium.
• 1986: Black Tulip, Geert Hageman, Netherlands.
• 1989: Gene Shears – James Haseloff and Wayne Gerlach, Australia.
• 1990: Crown Gall Bactericide – Dr. Alan Kerr, Australia.
• 1991: Long-life Tomato, USA.

On a Farm

On a farm

The plow and irrigation have tamed more farmland than any other farming inventions. People first grew crops in the Middle East about 10,000 years ago, but planting, harvesting and watering them by hand was a slow process.

In Egypt and India, nearly 4,500 years later, farmers prepared the ground for planting with wooden plows pulled by oxen. The Egyptians invented a machine called a shaduf, which helped them take water from the River Nile to irrigate or water their crops. Barbed wire was another great farming invention. Farmers used it to divide huge areas of Africa, North America and Australia into separate wheat, cattle and sheep farms in the 1800s. These enormous new farms revolutionized farming. Farmers now needed faster ways of harvesting grain, wool, meat and milk. The old methods were soon replaced by machines that did the work of hundreds of people.

Spade

Wooden spades with iron blades were invented by the Romans about 2,000 years ago.

Barbed wire

In 1867, American Lucien Smith invented barbed wire and made it possible for farmers to fence off their lands.

Cows and barbed wire. Photo by Elena.

Four jobs in one

In 1884, Australian Hugh McKay invented the horse-drawn harvester. It combined cutting, threshing, winnowing and bagging wheat grain into one operation. Combine harvesters with gasoline or diesel engines are now used 24 hours a day, with lights at night, to harvest the crops.

Watering the Crops

The Egyptian shaduf is a little like a seesaw. A long wooden pole, balanced on a crossbeam, has a rope and bucket at one end, and a heavy stone weight to counterbalance it at the other. The weight of the rock makes it easier to lift a heavy bucket of water.

Did you Know?

Superphosphates – aftificial chemicals that enrich the soil – were invented by Sir John Bennett Lawes in England in 1842. But fertilizers often run into the rivers and oceans, killing fish and making algae grow,

Plow

Plows made from wood and stag antlers were invented in Egypt and India about 5,500 years ago. Simple ox-drawn plows are still used on family farms in many countries.

Tractor

Three-wheeled steam tractors, built by the Case company of America in 1829, were very heavy and often became stuck in the soft soil. Modern tractors were pioneered by Henry Ford in 1907.

Time-line

• 1794: Cotton Gin (separator) – Catherine Green and Eli Whitney, USA.
• 1831: Grain Reaper (Cutter) - Cyrus McCormick, USA.
• 1833: Steel Plow – John Lane, USA.
• 1860: Nutriculture – Julius vos Sachs, Germany.
• 1868: Granny Smith Apple – Maria Smith, Australia.
• 1889: Modern Milking Machine, William Murchland, Scottland.
• 1924: Aerial Crop Dusting, USA.
• 1939: Dot Pesticide: Paul Muller, Switzerland.
• 1975: Axial Combine Harvester – International Harvester, New Holland, USA.

The Ways of Water

The Ways of Water

Water covers more than two-thirds of the Earth's surface and is constantly on the move. It rushes along rivers and streams ; it flows into oceans.

This endless movement of water creates energy that can be harnessed. For centuries, people have channeled flowing water into waterwheels that turn to grind grain. Hydroelectric power stations use water in a similar way, but to generate electricity. These enormous concrete constructions are usually found in mountainous regions where there is a high rainfall. Engineers build huge dams across steep-sided valleys. Turbines (modern versions of ancient wooden waterwheels) are placed in the path of the water that gushes with force through the dam. This torrent of water strikes the angled blades of the turbines, which begin to spin and extract an incredible amount of energy from the water. The process of producing hydroelectric power is set in motion.

Control room

The operation of the entire power plant is directed from the control room.

Watering the land

The water for this insectlike irrigation system is coming from the dam of a hydroelectric power station.

Transmission lines

Strengthened electric cables called transmission lines carry electricity away from the power plant.

Way of Water. Photo by Elena.

Spillway

The spillway gates are opened to release water when the level of water behind the dam is too high.

Reservoir

The deep lake that forms behind the dam wall is called a reservoir. The reservoir is built to make sure there is always enough water to operate the generators.

Dam Walls

There are usually curved to withstand the enormous force of water pressing against them. The walls are thicker at the base than the top.

Transformers

Transformers boost the electrical force from the generators to more than 200,000 volts.

Penstock

This channels water from the reservoir through the dam to the turbines

Generators

The spinning turbines are connected by shafts to electricity generators. When the turbines spin, the generators make electricity.

Turbines

Water flowing through tunnels in the dam makes the turbines spin at high speed. Once the energy has been removed, the water flows away through the center of the turbines.

Make Your Own Waterwheel

Cut four pieces of cardboard 1 ½ in x ¾ in and collect an empty thread spool and drinking straw (Step 1) to Glue each piece of cardboard to the thread spool (Step 2) and push the drinking straw through the middle so that your waterwheel can spin easily. Hold the wheel under a running faucet. When water hits the card paddles, the wheel will turn (Step 3).

A Daily Grind

Water-powered hammers are used in Laos in Southeast Asia to grind rice. When the paddles are turned by the flow of the river, the crossbeam at the end of the axle raises the hammer, then releases it to fall on the rice below.

Myths and Legends

Myths and Legends

Using Air and Wind

For thousands of years, people have told stories of wondrous beings that moved through the sky with the grace and ease of the birds. The ability to fly was seen as a sign of greatness and power. The gods and the heroes of many myths and legends were set apart from ordinary people because the could fly. In Greek mythology, Icarus and Daedalus flew on wings made of feathers, twine and wax; King Kaj Kaoos of Persia harnessed eagles to his throne, while Count Twardowski of Poland flew to the moon on the back of a rooster.

Many people were inspired by visions of joining their heroes in the sky. They strapped wings to their arms and jumped off towers, high buildings and even out of balloons. Some did survive their dramatic falls. In 1507, Scotsman John Damian leapt from the walls of a castle with wings made of chicken feathers and broke only his thing. He thought he would have been more successful if he had used the feathers of a bird that could really fly.

The modern hero Superman can fly “faster than a speeding bullet”. It seems our desire to believe in flying heroes continues.

A Sky Bird

The Garuda was a giant bird that carried the Indian god Vishnu across the sky. It is also the name of Indonesia's national airline, which uses the mythical bird for its logo.

A Chariot of Wings

Alexander the Great was said to have flown by harnessing six griffins, mythical winged animals, to a basket. He placed meat on his spear and enticed them to fly after it.

A Winged Horse

According to Greek legend, Bellerophon the Valiant, son of the King of Corinth, captured a winged horse called Pegasus. He flew through the clouds to find and defeat in battle the triple-headed monster, Chimera.

Flying God. Photo by Elena.

Reaching for the Sunday

In Greek mythology, Daedalus and his son Icarus used was-and-feather wings to escape from the island of Crete. But Icarus flew too close to the sun and the was on his wings melted. He fell into the Aegean Sea and drowned.

Tower Jumpers

Through the centuries, humans have tried to copy the birds. With elaborate wings made of feathers, they jumped from towers and flapped their arms desperately as the plummeted to to ground. They did not know that humans are too heavy, and their muscles are not strong enough to fly like birds. The hearts of humans cannot pump blood fast enough to meet the demands of wing flapping, which even in a sparrow is 800 heartbeats a minute.

A Touch of Spring

The Egyptian goddess Queen Isis had wings like a falcon. Each year she flew over the Earth and brought spring to the land.

Sky Battle

In many legends, the forces of both good and evil had the power to fly. St. Michel defended islands against deadly dragons.

King Kong, a legend. Photo by Elena.

Wind Power

Wind Power

Using the elements

People have used the power of the wind for more than 5,000 years. It propelled their sailing boats over rivers, lakes and oceans; it turned the heavy blades of windmills to grind grain and pump water. Wind has energy because it is always moving in one direction or another. This energy can be caught, or harnessed, by large sails or blades.

When electricity was developed in the nineteenth century, wind power did not seem as efficient as this marvelous new source of power, and most windmills disappeared. But wind power is making a comeback. Today, modern versions of windmills called wind turbines are used to generate electricity. Groups of wind turbines with long, thin metal or plastic blades, which look like airplane propellers on top of tall thin towers, are often erected together in wind farms that stretch across the landscape. By the middle of the twenty-first century, one-tenths of the world's electricity could be powered by wind turbines.

Wind-Assisted Tanker

Some ships have stiff fiberglass sails as well as engines. They can save fuel by using sails whenever there is enough wind. Computers calculate the wind speed and indicate when it is time to unfold the sails.

The wind. Photograph by Elena.

Wind Farms

These are buit in very windy areas and are controller by computers that turn their blades into the wind. When the wind turns the blades, the spinning motion is converted into electricity.

Blades: The blades of the turbine are set at an angle that can be changed to suit the wind's speed of direction.

Gearbox: The gearbox, driven by the turbine shaft, controls the speed of the generator.

Generator: The generator converts the spinning motion into electricity.

Turbine shaft: Wind turns the blades, which turn the central turbine shaft. The speed of the shaft varies according to the strength of the wind.

Nacelle: The nacelle (the part that contains the machinery) pivots to keep the blades pointing into the wind. The angle of the blades is set automatically to suit the wind speed.

Tower: The tower holds the blades at a safe height above the ground and contains the cables that cary the electricity underground.

Times past

Windmills were used for many years to grind grain.

Cap: The cap carrying the sails could turn so that the sails faced into the wind.

Canvas-covered sails: Canvas sheeting stretched over the wooden frame of the sails caught the wind and moved the sails around.

Fantail: Wind blowing against the fantail made it spin and turned the mill cap until the sails faced the wind.

Grain hopper: Grain fell from a container, called a hopper, down to the two grindstones below.

Driveshaft: This used the turning motion of the sails to move the grindstones.

Grindstones: Two heavy stones rotated and crushed the grain beneath them.

Make Your Own Windmill

Cut one-third of the way across a square of paper from each corner, and make a small hole in each corner (Step 1). Pull the four corners into the middle of the sheet (Step 2). Fasten pa pushing a tack of drawing pin through the middle. Attach to a drinking straw at the back, making sure your windmill can spin freely (Step 3). Now blow on it or hold it in the breeze.

Our Games

At Play

Everyday life and our games

People are always inventing ways to have fun. The Egyptians threw stone balls at upright pins in a game similar to bowling about 5,000 years ago. The Greeks played soccer with inflated animal bladders about 2,500 years ago. Some games seem timeless – hopscotch, marbles, tick-tack-toe and rope skipping are as popular today as when they were first played.

 Dolls have delighted young and old for centuries. They have been made of many different materials, from apples and animal skins to china and plastic. In 1823, baby dolls were made to cry. Soon, they were talking as well. Today, the games industry is booming as inventors create new and exciting games that challenge all who play them. 

Checkmate

Chess was invented in about AD 500 in India. The moves we play today were first used in Europe in the mid-1900s. The winning position “checkmate” comes from shah mat, Arabic for the king is dead.

Barbie Doll

In 968, Ruth Handler invented Barbie, a dress-up doll complete with a wardrobe of clothes and a way of life. More than two billion Barbie dolls have been sold in 140 countries.

Barbie Dolls. Photo by Elena.

Did you know?

The very first roller skates invented by a Belgian musician Joseph Merlin in 1760, had wheels in one line – similar to today's rollerblades.

Lego

The Danish word leg-godt means to play well. Ole Kirk Christiansen chose the name “Lego” for his line of toys. By 1955, his toy plastic bricks that can be joined to construct things such as buildings, machines, people and animals, were known as Lego all over the world.

Name of ten pins

In 1845, nine-pin bowling had become so popular in the state of Connecticut that it encouraged heavy gambling. A law was passed that banned the game of bowling at nine pine. The eager bowlers added a tenth pin and kept on bowling.

Games, Games, Games

In 1972, American Nolan Bushnell invented the first successful computer game. It was like table tennis, and was called Pong. In 1978, Space Invaders was introduced and became a big success. Today's electronic games, such as Where in the World is Carmen Sandiego?, use full color animation, speed and constantly changing tactics to outwit even the best human players. The computer game Lunicus pits players against a giant bee!

A Monastic Life

A Monastic Life

Religious communities lived in monasteries or abbeys and these were the chief centers of art and leaning in Europe between the tenth and twelfth centuries. A single community often included several hundred men called monks, or women, called nuns, who lived in a walled settlement. The monks and nuns divided each day between worship, study and work. Monasteries were often located in the frontier areas of Europe among various nomadic tribes.

Monks built churches that looked like fortress because they were seen as strongholds of God in an evil world. People came there seeking peace from the violence and wars around them. Living areas of a monastery opened off a cloister – a covered walkway built around a square garden. After the fall of the Roman Empire in the fifth century, many building techniques were forgotten. Stone,masons had to rediscover how to build arched stone vaults so the churches had fireproof roofs. These vaults were like those built by the Romans, so the style is called Romanesque.

People liked living near a monastery. It often provided the only hospital or school in an area and travelers stayed at guest houses located within the monastery.

Sleeping Quarters

Dormitories in the abbey at the cathedral in Durham, England, has a trussed roof built from thick, roughly cut timbers. Light from large windows allowed the monks to read during their afternoon rest period. In the winter, the monks sat by a fire in the warming room then went to bed in the unheated dormitory upstairs. A door in the dormitory led into the church because the monks worshiped in the middle of the night.

Feeding the community

On feast days, the monks roasted a wild boar over a fire in the center of the floor of the kitchen at Glastonbury Abbey in Somerset, England. They cooked other dishes for the large community over the four fireplaces in the corners of the room.

Refectory

Twice a day, monks sat down in the refectory to eat their simple meals.

Monastic Life. Photo by Elena.

Cellar

The monks made cheese and candles, cured hams and brewed ale to stock their cellar with all the things the community needed.

Maria Laach Abbey

The twelfth-century Romanesque abbey west of Koblenz, Germany, has six towers decorated with dark stone. This scene reconstructs a typical monastery cloister next to the abbey church.

Growing food

The monks worked in the fields of the farm outside the monastery walls. They also cultivated a small herb garden where they grew the plants used to make medicines.

Make pilgrimages

People rarely traveled in these times, but the did make a trip, or pilgrimage, to pray at the burial place of a Christian saint. Some pilgrims walked hundreds of miles to reach their goal, such as Santiago de Compostela in Spain. They slept in monastic guest houses and prayed at churches along the way. Pilgrims brought home new ideas from their travels, including new ways to build churches.

China and Japan Open Up

China and Japan Open Up

By the early 1800s, Europeans had set up trading bases in most countries except China and Japan. The Chinese hated foreign “barbarians” and allowed only Dutch and Portuguese merchants to trade in certain areas. Europeans first ventured into Japan in the 1500s, bringing Christianity with them. But in the 1600s, the ruling Tokugawa shoguns expelled all Europeans, except the Dutch. For the next 200 years, Japan was closed to the rest of the world. In the 1800s, the western powers tried to open up China and Japan for trade. In 1839, Britain went to war with China. Three years later, the Chinese signed a treaty giving Hong Kong to the British and allowing them to trade in other ports. In 1853, four American warships, led by Commodore Perry, sailed into Edo Bay (now Tokyo Bay) in Japan. Perry carried a letter from his president to the Japanese emperor, requesting trade ports. Japan and the United States signed a treaty a year later. The Japanese began to build railways and factories and soon became a major industrial nation.

Dutch Boy

From the 1600s to the 1850s, the Japanese allowed the Dutch to trade from an island in Nagasaki harbor. Japanese artists included Dutch figures in their art.

Opening up Japan

The Japanese were astonished at the sight of the stranger foreigners who sailed into Edo Bay in their black ships. Cautiously, they approached the steamships in small craft. The British, Russians and French soon followed the Americans into Japan. By the 1860s, many foreign diplomats and traders were living in Japan.

Japanese culture. Photo by Elena.

Opium Wars

The British East India Company began to bring the drug opium into into China from India to trade for Chinese tea. But it was illegal to trade in opium, and wars broke out between the Chinese government and the British.

Just like the West

After 1854, many Japanese, including the royal family, gave up their traditional costumes for western clothes. They wanted their people to be as modern as those in the West.

Boxer Rebellion

Some Chinese hated anything that was foreign. They formed a secret group called Yihequan (Righteous and Harmonious Fists), nicknamed the Boxers. In 1900, they attacked foreign factories, railways, churches and schools, and besieged diplomats in Peking for 55 days. Many Chinese and foreigners were killed in this rebellion. 

Fondations of Religions

Foundations of Religions

As early as 2500 BC, great civilizations flourished south of the Himalayan mountains, in what is now India. Three world religions began there – Hinduism, Buddhism and Jainism. All three teach that life, like a circle, has no end. It returns again and again as do the seasons. They believe that a person's soul comes back to to live another life in a new body.. This is called reincarnation. Hinduism began about 1500 BC. Hindus worship alone on most occasions, and many make pilgrimages to temples to pay homage to their gods. Hindu temples have richly decorated exteriors and pilgrims worship outside. The most important part of a temple is a small shrine with no windows, which is the home of the god.

A tall, curved shikhara, or tower, rises above the shrine, and a series of open porches are used for assemblies and religious dancing.

Did you know?

Even a small Hindu shrine can be seen from anywhere in a village because of the tall, carved shikhara above it. The shikhara represents a holy mountain that is thought of a staircase to the heavenly world.

Sri Ranganatha

The tower in Mysore, India is one of 15 giant gateways trough the five walls that enclose a Hindu shrine. The gateways were built between the eleventh and seventeenth centuries. The shrine itself is quite small and crowded by the priests' houses and the assembly rooms for pilgrims.

Ranarpur Temple

The Ranakpur temple honors Mahavira, the founder of Jainism. Jains believe that a person lives many lives, including those of animals. Jains try not to hurt any living creatures. One of Ranakpur's large corbeled domes rises above the courtyard. The dome rests on two stories of columns and is surrounded by smaller domes.

Fondation of Religions. Photo by Elena.

Building in Rock

In the second century BC, Buddhist monks built a monastery at Ajanta by cutting artificial caves into the cliffs above the river. Carvers chipped off unwanted rock and carried it away leaving a building behind. The columned entrance of the vihara, where the monks lived, led to a rectangular room surrounded by galleries. Each monk had a square cave that opened onto a gallery. Stone walls and ceilings were rubbed smooth then covered with paintings or carved with sculpture. The monastery also had a chaitya, or meeting hall, where people gathered to worship and study.

Myth in stone

The lively sculptures on the outside of Kandariya Mahadero represent many of the figures in stories from Hindy mythology.

Kandarya Mahadeo Temple

More than 1,000 carved figures cover this eleventh-century temple in Khajuraho,  At first glance it looks like a mountain of rock covered with rows of sculpture. The temple stands on a high platform with the shrine under the tall shikhara at one end a deep entrance at the other. Processions move through a passageway, which wraps around the halls and shrine.

Temple floor plan

Mathematical rules control the design of Hindu temples. Many small squares make up the floor plan of the temple. A square which never changes, symbolizes the heavenly world.

Heavens Meets Earth

Heaven Meets Earth

Christians believe in Jesus, the son of God, and their religion is based on his life and teachings. Christians were persecuted for many years during the Roman Empire, but in AD 313 Emperor Constantine made the religion legal. He then left the city of Rome and moved east by Byzantium and established a new Christian capital named Constantinople, which is now Istanbul in Turkey.

The Roman Empire later split into east and west. The western empire collapsed after it was invaded many times by nomadic tribes from central Asia,, but the eastern part survived to become the Byzantine Empire. Christianity as it developed there is called Orthodox Christianity. Hagia Sophia was the magnificent Orthodox church in Constantinople and it inspired builders of Orthodox churches for centuries. The great dome at the center of the church represented the heavens. The floor below represented life on Earth.

The Pantheon

For many years, the dome of the Pantheon, in Rome, Italy, baffled modern engineers. They did not know how the ancient Romans managed to build such a large dome. Then they discovered that the dome was made of concrete that becomes lighter as it gets higher because each level is mixed with lighter stones such as volcanic pumice.

For many hundreds of years the dome of the Pantheon was the largest in the world. It measures 142 ft across and is the same in height. Walls 16 ft thick buttress the base of the dome.

Wall of a Temple. Photo by Elena.

The church today

Four towers called minarets surround Hagia Sophia. They were added when the Islamic Ottoman Turks, founders of modern Turkey, conquered the Byzantine Empire and converted the church into a mosque.

Central dome

The large, lightweight dome is built of a single layer of brick and is 107 ft wide. It has a row of arched windows cut into its base.

The Congregation

There were no seats in Hagia Sophia. Worshippers stood in the space beyond the columns – the men in the aisle below and the women in the gallery above – to listen to the singing of the Orthodox church service.

Half domes

A half dome at each end lengthens the nave to 250 ft and buttresses the main dome by pressing against its base.

Decorating with Mosaics

A mosaic is a design of picture made up of small pieces of colored glass or stone that are mounted on a wall or ceiling. Mosaics seem to glow in the dimmest light. At one time, many colorful mosaics covered the ceilings of Hagia Sophia. Jesus and other great leaders and heroes of Christianity were portrayed in mosaics against a gold background, which symbolized Heaven.

Hagia Sophia

Byzantine architects began this church in Constantunople in 532, during the reign of Emperor Justinian. They finished it six years and it soon became the model for future Orthodox churches. The clergy, the worldly ruler, under the great domes, where the teaching of Jesus were read.

Hunter to Trader

Hunter to Trader

Early Trade and Exploration

The world looked very different 20,000 years ago. Great glaciers, caused by an ice age, covered much of the land. The people who lived at this time were hunters and gatherers, and they were always on the move. They followed herds of animals; gathered wild nuts, berries, plants and shellfish; and fished the rivers. They traveled long distances for things they valued, such as flint for making tools and weapons.

Gradually, they drifted across much of Europe and Asia, and crossed into North America. At the end of the last ice age, around 10,000 BC, the glacier thawed and lush forest grew. As the climate changed, so did the way humans lived. Many continued to hunt and gather food, but people in the Middle East planted crops and bred animals. They made pots, wove cloth, and used metals such as gold. Soon they started to trade with other villages for goods they could not produce themselves.

On the move

A group of hunters and gatherers in North America follows a herd of caribou as they migrate between summer and winter pastures. The people carry all their possessions as well as their flint-tipped spears and arrows for hunting.

Past Reflections

People made utensils and tools from obsidian, a black volcanic glass that was highly valued. Almost 9,000 years ago, women at Catai Huyuk in Turkey used obsidian mirrors such as this to put on their make-up.

Flint Ax

Hunters used bone or wood to chip flint stones into tools with sharp edges.

Survival Tools

Hunters and gatherers caught they prey with weapons such as wooden daggers with deer-horn points, harpoons made from wood (middle) and spearheads made from deer bone with flint set in carved grovers.

Nature. Photo by Elena.

Golden Bull

This bull made of gold came from Bulgaria. People often traded for precious metals, such as gold.

Working the Land

Early farmers in the Middle East made the first plows and harnessed oxen to them. Thousands of years later, this farmer in central India users similar tools to plow his land.

Village Life

The town of Catal Huyuk, in southern Turkey, is one of the oldest towns in the world. People built these mud-brick houses, which were joined together and entered through the roofs, in 7000 BC. Some of the houses were special shrines, decorated with will paintings, for worshiping the gods. The people herded cattle; grew wheat, barley and peas; and were skilled cloth-makers. They had plenty of obsidian and exchanged it for goods from other areas. Catal Huyuk soon became a busy trading center.

Ancient Egypt

Discovering Ancient Egypt

How can you discover ancient Egypt? You can visit the pharaoh's treasures in the world's great museums. You can read travelers' tales recorded by writers of the past, such as the Greek historian Herodotus, and you can learn fro Egyptologists. When. When Napoleon Bonaparte's army invaded Egypt in 1798, the French discovered many of its ancient treasures. Since then Egyptologists have studied monuments, painted friezes, objects from the tombs and things people threw away that the dry climate has preserved. They have deciphered records of daily events and other writing that survives on stone and papyrus. If you ever visit Egypt, you will be able to see the people who now live beside the Nile. They still use some of the old farming methods, and tools have changed little since ancient times. But their crops no longer depend on the time of inundation or flooding, because the Aswan Dam now controls Egypt's lifeline.

Dynasties of Ancient Egypt

Egyptologists have pieced together the sequence of the kings of ancient Egypt from fragments of inscribed stone and papyrus. Generally, a dynasty lasted for the time one family or group of pharaohs was in power. There were three very successful periods. During the Old Kingdom, the first pyramid at Saqqara and the Great Pyramid at Giza were built. In the Middle Kingdom, trade expanded and arts, crafts and temple building flourished. The Hyksos were expelled at the beginning of the New Kingdom and the pharaohs of this time established en empire.

Ancient Egypt in the Ice Age. Photo by Elena.

Did you know a few things about Ancient Egypt?

To save them from the rising waters of Lake Nasser, the temples from Philae Island were taken piece by piece to Agilkia Island and rebuilt..

When the pyramids were built at Giza, desert surrounded them. Now, the suburbs of Cairo are creeping close to them.

The British Museum displays coffins and mummies. The Cairo Museum has objects from Tutankhamun's tomb. The temple of Dendur has been rebuilt in New York<s Metropolitan Museum of Art.

The great Sphinx at Giza is showing its age. From time to time expert restorers have erected scaffolding to maker repairs.

The voyage or Ra II: Norvegian scientist Thor Heyerdahl wanted to test the seaworthiness of reed boats. In 1970, he built Ra II from bundles of papyrus lashed together with rope. It took 57 days to sail from Morocco to the West Indies. This did not show that the ancient Egyptians made such a journey, but it did prove that papyrus vessels were capable of surviving long sea voyages.

New Design

Manhattan – A New Design

The construction of an innovative buildings is difficult and often requires new techniques and special building materials. Many unexpected problems arise no matter how careful the advance planning may be. The architects and engineers face major obstacles to introduce innovative methods and to work out a way to actually build new buildings.

All the pictures have been taken by Elena.

A great building can reflect many different ideas and styles and tells us about the values and beliefs of the people who design and build it.

These buildings have thing, lightweight roof, which was made by pouring concrete over a tightly stretched wire mesh.

Ancient buildings around the world looked different because they were shaped by the building materials available. Each material inspired  a different construction method.

Broadway and Toronto Dominion Bank on sight.

Metals, plastic and glass from around the world are used in this buildings.

There are always many unexpected costs and delays in construction.

Their roofs are designed to be made of prestressed concrete.

Large international corporations are building impressive and functional buildings. Many of these giant buildings can be seen all over Manhattan.

As space became scarce, corporations needed high-rise buildings, so architects and engineers designed skycrapers to withstand earthquakes.

Modern buildings dot the New York  skyline, but modern lifestyles affect their future.

Each new generation of architects and engineers will face many new obstacles and technological opportunities.

Architects will create different building materials, methods and architectural styles to meet new challenges. 

St. Andrew's church in the heart of Manhattan.

Trinity church, one of the oldest Christian temples on Manhattan.

Stone Jungle. New York, New York.

Place in front of the Trump Center, near the Central Park of New York.