science has changed human life altogether. The fabrics that we wear are manufactured in the factories. The machine that we use in every day life, are manufactured in most parts of the world. The cookers, the coolers, the refrigerators, radio-sets, television-sets, cameras, telephones, wireless system, telescopes, microscopes, and other such instruments have become sources of human comfort. Man may converse with his friends and relatives living thousands of miles away. We have seen the pictures of the planets reach our earth through space by electronically fitted cameras . A man sitting on earth may see the surface of the mars millions of miles away in space. The buses, cars, bikes, ships, aeroplanes, scooters and even bicycles have minimized distance to a greater extent. To reach New York from Delhi is a matter of hours. The know of the vast caravans of traders treeking their way through the deserts of Rajasthan.