Acid rains

CHRISTOPHER COLUMBUS

In the fifteenth century people knew only three conti­nents: Europe, Asia and Africa. They knew nothing about such a big continent as America.

The man who was thought to be the discoverer of America was born in 1451 in Italy. His name was Chris­topher Columbus. He probably worked as a weaver be­fore going to sea.

At that time the life of a sailor was full of adventure and danger, so Columbus had many exciting experienc­es. Once during a battle with a vessel off the coast of Por­tugal, he had to leave his boat and swim to the shore a long distance away. He afterwards lived in Portugal a number of years, and while there, he married the daugh­ter of a sea captain. For some time he earned his living, partly by making sea voyages, and partly by drawing maps and selling them.

Knowing that the earth was round, he decided to reach India by sailing to the west. It was very difficult for him to organise his expedition as nobody wanted to help him. Many years after, the Spanish government gave him some money for his expedition.

In 1492 he sailed with three small ships into the At­lantic Ocean. They had been sailing for more than two months. At last they saw land.

When they landed they saw strange trees and flow­ers. Men and women with olive coloured skins gathered around them and looked at them with great surprise.

Columbus was certain that the lands he discovered were part of India, and he called these islands the West Indies. The people living there have been called Indians since then, though they have nothing in common with the real Indians — inhabitants of India.

His last voyage was made in 1502-1504. After that, seriously ill, he remained in Spain-until his death. He died believing that Cuba was part of Asia.

Every year more and more plants and animals disap­pear never to be seen again. Strangely, it is the most in­telligent but most thoughtless animal that is causing most of the problems — man. Nature is very carefully balanced and if this balance is disturbed, animals can disappear alarmingly fast. Every day, thousands of spe­cies of animals draw closer to extinction.

In many lakes fish are dying. Fishermen are worried because every year there are fewer fish and some lakes have no fish at all. Scientists are beginning to get wor­ried too. What is killing the fish?

The problem is acid rain. Acid rain is a kind of air pol­lution. It is caused by factories that burn coal or oil or gas. These factories send smoke high into the air. The wind often carries the smoke far from the factories. Some of the harmful substances in the smoke may come down with the rain hundreds of miles away.

The rain in many places isn't natural and clean any more. It's full of acid chemicals. When it falls in lakes, it changes them too. The lakes become more acidic. Acid water is like vinegar or lemon juice. It hurts when it gets in your eyes. It also kills the plants and animals that usu­ally live in lake water. That is why the fish are dying in lakes.

But dead fish may be just the beginning of the prob­lem. Scientists are finding other effects of acid rain. In

some large areas trees are dying. Not just one tree here and there, but whole forests. At first scientists couldn't understand why. There were no bugs or diseases in these trees. The weather was not dry. But now they think that the rain was the cause. Acid rain is making the earth more acidic in these areas. Some kinds of trees cannot live in the soil that is very acidic.

Дата добавления: 2014-11-06