Geography Reference
In-Depth Information
One reason Columbus was able to get as far as he did was his possession of what we think of today as a
fairly simple piece of technology. Every Boy Scout has one. There is probably one, in some form or other,
around every household. Some people keep one on the dashboard of their car. These devices are a source of
endless fascination, but most of us don't know what to do with them. They are magnetic compasses. They
work because of the earth's strange magnetic poles. These poles, a characteristic feature of this planet, are
not exactly the same as the geographic poles. The reason for the location of the magnetic poles remains a
mystery, and the earth's magnetic field has apparently reversed polarity many times in the geologic past.
Nonetheless, a magnetic needle will come to rest pointing approximately northward. With a card fixed un-
derneath indicating the point of direction, the compass user simply fixes the needle over the north point on
the compass card and can determine the precise direction in which to head.
People take these compasses for granted, and like a lot of other small conveniences in life, we don't
really understand how they work. In the case of the compass, like the wheel and a hundred other very basic
inventions that made human progress possible, we also don't know who invented it. Strange as it seems,
no one knows who discovered the magnetic property of the lodestone, or magnetite. We don't know who
figured out that the stone's attractive power could be passed on to a piece of iron, or who discovered that
the magnet could be used in determining geographic directions.
Like many unexplained phenomena of nature, the lodestone was the source of legends before its prac-
ticality was discovered. One such legend was the existence of magnetic islands through which ships could
not pass if they were built with nails. From earliest times, the remarkable powers of the lodestone—the
word comes from an obscure Old English word for
way
, so a rough translation is “stone that shows the
way”—were associated with dark, magical forces.
In medieval Europe, magnets were in fact used by magicians to perform crowd-pleasing tricks. Accord-
ing to another legend, a piece of lodestone placed under the pillow of an unfaithful wife could make her
confess her sins. The mineral was said to be so potent that a small piece could cure all sorts of ailments
and even act as a contraceptive. According to Simon Berthon in his topic about map history,
The Shape of
the World
, the compass was also said to “have the power to reconcile husbands to their wives, and recall
brides to their husbands.”
And in
The Discoverers
, Daniel Boorstin recounts, “Since this inexplicable power of a magnetized
needle to 'find' the north smacked of black magic, common seamen were wary of its powers. For many
decades, the prudent sea captain consulted his compass secretly. . . . After the compass had lost its occult
flavor and become every sailor's everyday tool, it came out onto the open deck. Still, in Columbus's day, a
pilot who used the magnetic compass might be accused of trafficking with Satan.”
The Chinese were the first, perhaps around
AD
1000, to use a magnetic needle for navigational pur-
poses. While the strange power of the lodestone was known in both the East and the West, the Chinese
were the first to master this phenomenon and to invent the compass. Four hundred years later, the Chinese
were sufficiently well-versed with compass and seagoing navigation to mount ambitious sailing expedi-
tions under a famous admiral, Zheng He, who was known as the Three-Jewel Eunuch, perhaps because
he gave gems as gifts. With some sixty large ships capable of carrying thirty-seven thousand men, Zheng
He carried the message of Chinese superiority to the trading nations of the Indian Ocean. By 1431, Zheng
He had established China's preeminence throughout the southern seas, all the way to India, Arabia, and
East Africa, well before Europeans seriously attempted voyages to this part of the world. Ironically, Zheng
He's seventh voyage was his last. Court politics put an end to foreign adventures and China, the nation
that built the Great Wall to keep out foreigners, once again turned inward. Rejecting a spirit of agressive
inventiveness and exploration, the xenophobic Chinese cut short an exploring era that might have changed
the course of history had it been permitted to flourish.
