Isaac Newton was born in 1642 at Woolsthorpe in Lincolnshire. He did not show any signs of cleverness in his early schooldays. When he grew older his mother wanted him to help her on the farm, for his father was dead. But the boy did not like this; he was now fascinated by mathematics, and in 1661 he went to Cambridge University, where he took first degree four years later. Then the Great Plague came. The university was closed, and Newton went back to his quiet home in Woolsthorpe. It was during the next few months that he carried out his first important researches into the nature of light. Newton’s original reflector, completed about 1671, had a mirror two and a half centimeters across; the largest telescope in the world today has a mirror over 500 centimeters across! He went back to Cambridge as soon as the Plague danger was over. He became the Fellow of the Royal Society, and came into contact with many other brilliant men. Among them there were Christopher Wren, and Edmund Halley. It has been said that Newton was sitting in his Woolsthorpe garden when he saw an apple fall off a tree. This started a chain of thoughts in his mind, and he realized that the force pulling on the apple was the same as the force which keeps the Moon in its path round the Earth. From this he was led to draw up the laws of gravitation. There is strong evidence that this story – unlike most of its kind – is true. At any rate, Halley persuaded Newton to rework the calculation, and public them in a book. The result was the great volume known generally as “The Principia”. It was completed in 1687. For many years Newton served as president of the Royal Society. When he died, in 1727, he was buried in Westminster Abbey.