For centuries people did not know what lightning was. Ancient Indians believed that it was Lord Indra's weapon. The Romans believed that it was Jupiter's. All such myths were exploded in the 18th century by an American named Benjamin Franklin. One stormy day, he sent up a kite with a metal key tied to a string. He was out to prove that lightning was an electric charge coming down. After the kite had been up for some time, he brought his finger near the key. It gave off sparks. This happened because electric charge from a charged cloud had come down to the kite and had travelled down the wet string. It was a very dangerous experiment. Benjamin Franklin could have got killed if the charge had been more powerful.
            But now he had proof that lightning was an electric discharge. Putting this knowledge to use, he built the first lightning conductor and put it up on the house of a businessman in Philadelphia. During the monsoon when there are strong winds, the clouds rub against each other and develop electrical charges. Later, when the winds die down, the clouds stop moving around so much. If one such cloud stops over a building, the portion of the building nearest the cloud acquires opposite charge. When the charge is powerful enough it makes the charge from the cloud come down. This reults in lightning.
            The lightning conductor is nothing but a metal rod attached to the top of the building. The metal rod is connected to the earth by a copper wire. If a building has a lightning conductor and there is a charged cloud over the building, then it is the conductor which acquires the opposite charge because it is nearer to the cloud. This opposite charge is continuously sent down into the earth through the copper wire in the conductor. By not permitting the opposite charge to become powerful enough to make the charge from the cloud come down, the conductor prevents lightning.
             In the beginning, people did not want to use lightning conductors. They felt if God wanted to strike a particular building with lightning, it was not right for man to stop him.
             Nowadays, lightning conductors are a very common sight everywhere. Thunder and Lightning occur at the same time but we see the flash of lightning before we hear the peal of thunder. This happens because light travels faster than sound. If you are caught in the open during a thunderstorm, never stand under a tree because of its height will be the first to get hit by lightning.

Benjamin Franklin


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