The Story of Great Inventions

the First Gr

sand years ago. Syracuse was a Greek city on the island of Sicily. The Kin

moving some very heavy weight. Whereupon Archimedes caused one of the King's galleys to be drawn ashore. This required many hands and much labor. Having manned the ship and put on board her usual loading, he placed himself at a distance and easily moved with his hand the end of a machine which

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o an alliance with Carthage. His cruelty toward his own people was so great that, after a short reign, he was assassinated. There was anarchy in Syracuse for a time, the Roman and anti-Roman parties striving for supremacy. The ant

E BATTLE

d by the inventi

ould conquer the city. But there are times when one man with brains is worth more than an army.

lay along a chain of hills with overhanging brows; on the

owed by the outer oars of each of the pair. On each pair of ships was a ladder four feet wide and of a height to reach to the top of the wall. Each side of the ladder was protected by a railing, and a small roof-like covering, called a penthouse, was fastened to the upper end

hit by the crossbows, they found that Archimedes had another contrivance ready. He had pierced the wall as high as a man's head with many loopholes which on the outside were about as big as the palm of the hand. Inside the wall he had stationed archers and men with crossbows to shoot down the marines. By these means he not only baffled the enemy, but killed the greater number of them. When they tried to use their ladders, they discovered that he had cranes ready all along the walls, not visi

crane. The hook was dropped on the prow of a ship, and when it had taken hold the ship was lifted until

ere used. The Romans were reduced to such a state of terror that "if they saw but a rope or a stick put over

admired the genius of Archimedes that he gave orders that he should not be injured.

at as could possibly be, was put to death by a soldier who did not know who he was; that Marcellus was greatly grieved at this, and that pains w

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of gold. In due time the crown was brought to the King, and a beautiful piece of work it was. The weight of the crown was the same as that of the gold, but a report was circulated that some of the

body became immersed the water ran out of the tub. He quickly saw how he could solve the problem, leaped out of the b

he crown, and a large vase full of water, he proved that the crown was

s lead-soled shoes could scarcely walk on land, but walks easily under water. When the diver comes up, the place where he was immediately becomes filled with water. Now, whatever that water weighs which fills the diver's place, just that much weight will the diver lose when he goes do

endless screw (worm gear), and the water snail, or Archimedean screw. Yet his delight was not in his machines, but in his mathematics. Th

of the An

with this view of Archimedes. His view, however, was that of other learned men of his time, that the common need

ich the first cog-wheels were used, was invented by another Greek named Ktesibus, who also invented the force-pump. The suctio

s, such as dust or chaff. Amber was called by the Greeks "electron," because it reflected the brightness of the

an of electricity. In fact, their ideas of magnets cannot

nly found the iron ferrule of his staff and the nails of his shoes adhering to a st

agnets, and of ships sailing near the magnetic mountains when every nail and piece of