Category Scientist & Invensions

When were contact lenses invented?

The first contact lenses were made by A.E. Fick in 1887, but were not successful. During the early part of this century opticians tried to produce extremely thin shell-like lenses to fit closely over the eye. An impression was taken of the eye and a glass shell made which, with a suitable fluid under it, covered most of the eye. After 1938, plastic was used instead of glass, and in about 1950, smaller lenses were introduced which covered only the cornea and floated on a layer of tears. These lenses, only 7 to 11 mm in diameter and 0.1 to 1mm thick can usually be worn all day without being removed.

    Besides being invisible, contact lenses provide a much wider field of vision than spectacles. They are more practical for use in active sports because they are not easily lost or broken, and they can be tinted for use as sunglasses. But contact lenses are not effective in all cases of eye trouble. They are also expensive, and some people find difficulty in learning to wear them.

    As research continues, even smaller and more flexible lenses are being developed.

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When was the thermometer invented?

 

 

The fist practical thermometer or instrument for measuring temperature was invented shortly before the end of the 16th century by the famous Italian astronomer Galileo. It was an air thermometer giving only a rough indication of the degrees of heat and cold, and later he increased its efficiency by using alcohol instead of air.

       The principle on which most thermometer work is that a liquid or gas used for measuring expands or contracts with changes in temperature more rapidly than the glass containing it. Thus when a coloured liquid is confined in a thin glass tube the difference in expansion, as shown by the level of the liquid against a graduated scale, indicates the temperature.

    About 1714 the German scientists Gabriel Daniel Fahrenheit designed a thermometer which, for the first time, used mercury as the measuring agent. He also introduced the scale named after him in which 320 is the freezing point of water and 2120 the boiling point. Mercury is still used in most thermometers because it has a high boiling point (6740) and a low freezing point (-380).

    An alcohol thermometer, still in use in some countries, was made by Rene de Reaumur, a French naturalist, about 1731. About 11 years later Andres Celsius, a Swedish astronomer, used the centigrade scale for the first time, with freezing point 00 and boiling point at 1000.

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Who first used a powered dental drill?

The first powered dentist’s drill was made by George Washington’s dentist, John Greenwood, who adapted his mother’s spinning wheel with its foot treadle to rotate his instrument.

    Earlier dentists had operated their drills by means of bowstrings, a method which must have required skill, determination and physical stamina on the part of the dentist, as well as a great deal of courage from the patient. Later drills were operated by turning a handle at the side.

In 1829 James Nasmyth, the Scottish inventor of the steam hammer, used rotary power to improve the efficiency of the drill. A hand-operated drill with a flexible cable was patented by Charles Merry, an American dentist in 1858; and George Harrington, an Englishman, invented in 1864 a drill driven by a clockwork motor.

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Who sent the first radio message?

Guglielmo Marconi is usually credited with sending the first radio message. Marconi was born in Bologna, Italy; He came to England in 1896 and obtained a British patent for his wireless telegraphy system. In 1897 he established a radio transmitter on the roof of the post office at St Martin’s-Le-Grand in London, and sent a message a distance of a few hundred yards.

       He continued to improve his apparatus, and in 1898 radio was installed aboard a ship at sea, the East Goodwin lightship off the south-east coast of England. In the following year wireless messages were sent across the English Channel.

    The first radio transmission across the Atlantic was on December 12, 1901 from a station on the cliffs at poldhu, in Cornwall, and the message, three dots representing the letter S in the Morse code, was picked up at St John’s in Newfoundland.

     The existence of radio waves was first demonstrated by Heinrich Hertz, a German professor, in 1887. Marconi based his experiments on Hertz’s research.

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Who invented the Aero Plane?

The first aero plane ever to fly was built by a French naval officer, Felix du Temple de la Croix. In 1874 his monoplane, powered with a hot-air engine, took off from the top of a hill near Brest in France. It did not get far, just a short hop, but it was a beginning. A few years later, in 1890, Clement Ader of France flew his own plane, Eole, entirely under its own power for about 50 meters. It was a world record.

     The first truly successful aero plane flight was in 1903. In December of that year Orville Wright flew his chain-driven plane Flyer I at a speed of 8m.p.h and at an altitude of 12 feet for 12 seconds in North Carolina, United States. It was several years before the Wrights’ achievements were fully appreciated in America.

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Who invented the Wankel engine?

Felix Wankel, a German motor engineer, invented the rotary piston engine which bears his name. Deprived of a university education when his family’s fortune vanished in the German inflation of 1919-20, he went in for car repairing and set up his own business in 1924 at the age of 22.

        Soon he began work at designing a rotary piston engine, an idea which had attracted engineers since the invention of the stream engine. From 1934 to 1936 his research was backed by B.M.W. and from 1936 to 1945 by the German air force. In 1951 he established his own research institute and financed it by working as a consultant.

Wankel succeeded in discovering the secret of effective seals between the rotating pistons and the casing. He also discovered the geometrical form of an engine that could carry out the four-stroke cycle in one chamber without valves, giving a useful high compression ratio. His engine ran successfully for the first February, 1957. N.S.U. began limited production of Wankel engines for a car is 1963, and went into large-scale production in 1967.

      The rotary piston engine challenges the usual internal combustion engine, using reciprocating pistons, because it offers reduced size, weight, vibration, noise and production costs for comparable thermal efficiency. It is considered suitable for industrial, marine and aeronautical uses.

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