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The first Chinese compasses were pieces of a magnetic mineral called lodestone. Earth itself is like a giant magnet with north and south poles. Because lodestone is magnetic, it is influenced by Earth’s magnetic poles.
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By the 2nd century C.E., they started building ships with separate, watertight compartments. Builders divided the ships into sections and sealed each section with caulk, a sealant that keeps out water.
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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. -
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.
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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. -
Paper money was invented by the Chinese in the late 8th or early 9th century. Before that time, coins were the only form of currency. Like game cards, paper money was printed with wood blocks.
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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. -
th Early flamethrowers contained gunpowder mixed with oil. The Chinese used them to spray enemies with a stream of fire.
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Artillery shells, for example, exploded after being hurled at enemies by a war machine called a catapult. The sound of the exploding shells confused the enemy and terrified their horses. Small bombs, or grenades, were lit and thrown by hand.
