Made by: Chinch Virtoriya Teacher: Lyam

1. Made by: Chinch Virtoriya Teacher: LyamkiYuliana Alexander Graham Bell And his great invention

2. content: A.G.Bell`s biography Bell`s great invention is the first telephone The dreft of the first telefone Using the telefone in our life

3. A.G.Bell`s biography: Alexander Graham Bell was born on March 3, 1847, in Edinburgh. His father, Alexander Melville Bell, was an expert in vocal physiology and elocution; his grandfather, Alexander Bell, was an elocution professor. After studying at the University of Edinburgh and University College, London, Bell became his father's assistant. He taught the deaf to talk by adopting his father's system of visible speech. In 1865 Bell made scientific studies of the resonance of the mouth while speaking. In 1870 the Bells moved to Brantford, Ontario, Canada, to preserve Alexander's health. He went to Boston in 1871 to teach at Sarah Fuller's School for the Deaf, the first such school in the world.

4. From 1873 to 1876 Bell experimented with a phonautograph, a multiple telegraph, and an electric speaking telegraph (the telephone). Funds came from the fathers of two of his pupils; one of these men, Gardiner Hubbard, had a deaf daughter, Mabel, who later became Bell's wife. On Feb. 14, 1876, Bell's attorney filed for a patent. The exact hour was not recorded, but on that same day Elisha Gray filed his caveat (intention to invent) for a telephone.Other activities took much time. The magazine Science was founded in 1880 because of Bell's efforts.He was also involved in sheep breeding, hydrodynamics, and aviation projects.Aviation was Bell's primary interest after 1895.He aided Samuel Langley, invented the tetrahedral kite (1903), and founded the Aerial Experiment Association (1907), bringing together Glenn Curtiss, Francis Baldwin, and others. They devised the aileron control principle (which replaced "wing warping"), developed the hydroplane, and solved balance problems in flying machines. Curtiss furnished the motor for Bell's man-carrying kite in 1907.Bell died at Baddeck, Nova Scotia, on Aug. 2, 1922

5. Bell`s great invention: To help deaf children, Bell experimented in the summer of 1874 with a human ear and attached bones, a tympanum, magnets, and smoked glass. He conceived the theory of the telephone: an electric current can be made to change intensity precisely as air density varies during sound production. Unlike the telegraph's use of intermittent current, the telephone requires continuous current with varying intensity. That same year he invented a harmonic telegraph, to transmit several messages simultaneously over one wire, and a telephonic-telegraphic receiver. Trying to reproduce the human voice electrically, he became expert with electric wave transmission. Bell supplied the ideas; Thomas Watson made and assembled the equipment. Working with tuned reeds and magnets to synchronize a receiving instrument with a sender, they transmitted a musical note on June 2, 1875. Bell's telephone receiver and transmitter were identical: a thin disk in front of an electromagnet.

6. On Feb. 14, 1876, Bell's attorney filed for a patent. The exact hour was not recorded, but on that same day Elisha Gray filed his caveat (intention to invent) for a telephone. The U.S. Patent Office granted Bell the patent for the "electric speaking telephone" on March 7. It was the most valuable single patent ever issued, and it opened a new age in communication technology. Bell continued his experiments to improve the telephone's quality. By accident, Bell sent the first sentence, "Watson, come here; I want you, " on March 10, 1876. The first demonstration occurred at the American Academy of Arts and Sciences convention in Boston 2 months later. Bell's display at the Philadelphia Centennial Exposition a month later gained more publicity, and Emperor Dom Pedro of Brazil ordered 100 telephones for his country. The telephone, accorded only 18 words in the official catalog of the exposition, suddenly became the "star" attraction.

7. The dreft:

8. Using in our life: We can`t imargine our life without telefone. We use it every day. When people want to tel with there friends they call them. Also we can use it when we want to call another sityes or countries. The telefone is irreplaceable. We can know all news about our friends and netives seating in armchair. Telefone is very useful invention.