Blue Strips.

Tea

750 BCE

We know from written accounts that the Chinese have been drinking tea since at least 2700 B.C. For several
thousand years, tea—made by letting tea leaves steep in boiling water—was drunk mostly as medicine. However, by
the 8th century C.E., tea had become a hugely popular everyday beverage throughout China. Tea houses had sprung
up throughout the country.

The compass

250 BCE

Europeans also developed a compass using lodestone.
However, the Chinese eventually replaced the lodestone
with a steel needle. They had learned that rubbing a needle
with lodestone made the needle act in the same way as the
lodestone. However, needle in a compass gave a more
accurate reading than a piece of lodestone.

Steel

200 BCE

The Chinese first made steel, a very useful metal, before 200 B.C.E. Steel is made from iron, but it is less brittle than iron and easier to bend into different shapes.The earliest Chinese steel was made from cast iron. The Chinese were the first to learn how to make cast iron by melting and molding iron ore. Later they learned that blowing air into molten, or melted, cast iron causes a chemical
reaction that creates steel. Steel is a great deal stronger than iron.

Porcelain

50

Porcelain is made by combining clay with the minerals quartz and feldspar. The mixture is baked in a kiln, or pottery oven, at very high temperatures. The resulting pottery is white, hard, and waterproof. However, light can pass through it, so that despite its sturdiness it looks quite delicate and beautiful.

Printing

650

The invention of paper made another key development possible: printing. In about the 7th century, the Chinese invented a technique called woodblock printing. The printer first drew characters (symbols) on paper. He then glued the paper to a wooden block. When the glue was dry, the printer carved out the wood around
the characters, leaving the characters raised on the wood.

Clock

750

The Chinese developed the first mechanical clock in about the 8th
century. The new clock was more accurate than earlier timekeeping devices, such as sundials and hourglasses. The Chinese devised a wheel that made one complete turn every 24 hours. Dripping water made the wheel turn. Every quarter hour, drums would beat; and every hour, a bell would chime. The sounds let people know what time it was.

Game cards

850

Game cards were invented in China in about the 9th century. Printers used woodblock printing to make the cards from thick paper. Famous artists drew the designs that appeared on the backs
of the cards. Europeans were introduced to card games by the late 1300s. Today, card games are played throughout the world.

Gunpowder

950

The Chinese who first made gunpowder were alchemists, people who practiced a blend of science and magic known as alchemy. Alchemists experimented with mixtures of natural ingredients, trying
to find a substance that might allow people to live forever. They also searched for a way to make gold out of cheaper
metals.

Flamethrower

950

By the 10th century, the Chinese had made the first weapon that used gunpowder: the flamethrower. Early flamethrowers contained gunpowder mixed with oil. The Chinese used them to spray enemies with a stream of fire.

Rocket Technology

1300

Rocket technology was developed in China during the Song dynasty. Rockets were powered by a black powder made of saltpeter, charcoal, and sulfur. At first, rockets were used only in fireworks. Later, the Chinese used them as weapons. They even developed a two-stage rocket for their armies. The first stage propelled the rocket through the air. The second stage dropped arrows down on the enemy. By 1300, rockets had spread through much of Asia and into Europe.