Wednesday, October 7, 2009
These days most people like air travel, because it is fast, comfortable and safe means of journey. It takes a few hours to travel to a place thousand of kilometres away. But there is not much excitement in it because we can not see much of the world from the height at which aeroplanes fly.
Endeavours of fly have been made by man since long the first man who tried to fly was a Frenchman, Pilatre de Rozrer, who went up in a hot-air balloon on
The balloon flights were quite an important step towards the invention aeroplane. But balloons where found to be useless for his purpose unless they were made navigable. Mechanical power was needed for this purpose. An Englishman achieved remarkable success in this regard in 1848. He made an aeroplane fitted with a steam engine, but it proved too heavy to fly. In 1852 a Frenchman installed a steam engine in an airship but it also did not work swiftly. The French engineers Renard and Kerb used electric power in their airships, but batteries were too heavy.
The solution was provided by the invention of internal combustion engine in 1876 by a German named Otto. This piston – driven, engine worked on vaporized petrol. In 1886 Wolfert a German installed this engine in an airship, designed by count Vonzeppline whose first airship was manufactured in 1908. These airships were known as “Zeppelins”.
Developments in this regard continued in 1909 a Frenchman Bleriot designed an aeroplane and flew across the
Air ships were used for passenger services after First World War. But were abandoned due to unsafe conditions. The giant hanger at
Scientists like the British Maxwell, German Hertz and Italian Marconi have prophesied, discovered and exploited the wireless. Taking advantage of the invention of wireless Marconi invented the instrument which made to put the ideas of sending wireless waves to practical use.
James Clerks Maxwell who was born in 1831 out forward the theory that light and electricity are parts of the same thing. This theory of Maxwell was based on mathematical calculations. It was later observed that light waves and electricity waves moved at the same speed. He believed that signals can’t be sent without use of wire.
Heinrich Hertz a German made laboratory tests with short frequency electric waves to prove that Maxwell theory was correct. These waves were name Hertzian waves after him and they established the possibility of wireless communication. In 1894 Lodge showed that it was practicable.
Gugliemo Marconi experimented with a Morse Telegraph key and Telephone receiver and received the signal from one place to the other with out any wire, the standing aerial doubted the strength of wireless waves.
In 1896 Marconi went to
In 1903 Marconi Successfully transmitted wireless signal over long distances and showed that earth’s curve did not interfere with these waves.
In 1924 Marconi managed to direct wireless in a straight line. The invention opened up new vistas. After that it became possible to receive and send wireless waves carrying speech sound rather than sound signal. This led to the invention of radio.
Another scientist Baird invented the method of sending pictures by radio waves. That was the beginning of the television.
Another development of wireless waves is radar. It has made air traffic sage by making it possible to locate air craft.One of the latest developments of wireless is radio telescope. The invention is based on the discovery that starts emit wireless waves. The radio telescope has made the exploration of universe possible.
The author is highly educated person but he is afraid of a bank. He tells that as soon as he entered the premises of the bank he became very nervous and started behaving like an irresponsible fool. He wanted to open an account in bank because he got an increment and whished to save it in bank. He walked in asked the Accountant if he could see the Manager in private. The request was complied with. The manager took him to a private room believing that he was a detective. But when he told him that he only wanted to open an account and make initial deposits of 56 pounds. After knowing this manager was relieved and sent him back to the Accountant.As soon as account was opened he said that he wanted to draw a cheque. He wanted to withdraw only 6 pounds but he wrote a cheque of 56 pounds which was the amount deposited by him a few minutes before. Clerk was surprised to see such cheque and ejaculated if he was drawing it all out again. He realized his mistake but was so miserable that he made carelessly a decision to with draw the whole amount. He replied in affirmative. His account was closed and he walked out of the bank hearing a big roar of laughter from behind the door.