THE RADIO

                                  The invention of the telegraph, in the 1830's, showed how messages could be transmitted using electrical signals. But in order to send and receive messages between two places it was necessary that they were linked by wires.
                                  In 1864, the englishman, James Clerk Maxwell, predicted that messages could be sent by electrical signals even without wires. He was proved right in 1887, when Heinrich Hertz, a German physicist, succeeded in sending a signal over a very short distance without the use of wires.
                                 The first practical use of wireless transmission was, by a strange coincidence, demonstrated by two young inventors working different continents at about the same time.
                                  In Calcutta, in 1895, Jagadish Chandra Bose, using an improved version of Hertz's apparatus, transmitted a signal through a solid wall without the aid of wires, making it ring a bell and explode a mini mine. Guglielmo Marconi, a 20-year-old Italian, conducted a similar experiment in which he sent an electrical signal without wires and rang a bell at the other end of the room.
                                 And so, the foundation of modern broadcasting was firmly laid.
                                 Before long, in 1915, the human voice was broadcast for the first time across the Atlantic ocean. A message sent from Virginia, USA, was received by a French military radio station atop the Eiffel Tower in Paris. And sometime later the radio was designed.!

Radios Today

THE BICYCLE

           The first bicycle was built by a german, Baron Drais, in 1816. It had no pedals. He had to move it by pushing his feet, first one then the other, ground. People called him a madman. Children jeered at him whenever he passed by on his strange machine. Cycles with pedals first made their appearance around 1866. The pedals were fitted to the front wheel. If you turned the pedal once, the whole front wheel would turn. So front wheels were made larger and larger. The cycle called a penny-farthing, in England. The front wheels of these penny-farthings were sometimes more than five feet high. It was difficult to mount these cycles. But the real trouble began after you mounted them and started pedalling. The penny-farthing had no brakes! The only way you could dismount was by jumping off, which was not easy.
           As the years went by someone thought of putting the pedals in the centre; Another invented the roller chain. The front wheel was made smaller. The tyres were made of solid rubber and yet it was no fun if you had to ride over bad roads. The solid rubber tyres could not absorb the bumps.
           Then a young lad who did not like to be jolted when riding his cycle began to pester his father to do something about it. Finally, his father, John Dunlop had a brainwave. He cut up the garden hose, fixed the pieces of hose onto the wheels, pumped air into them and gave the cycle to his son. His son rode away as if he were riding on air which in a way he was. The air in the tyres absorbed the bumps, the cycle got on the way. Cycles thereafter began to use air-filled tyres.
           Today if our cycles are so safe and so comfortable to ride on, it is due to the efforts of all these men- from Baron Drais to John Dunlop, They made the modern cycle possible.

Baron Drais And The First Bicycle