مخترع الهاتف الكسندر غراهام بيل بالانكليزي

In 1847, Alexander Graham Bell was born into a family with a passion for communication. His grandfather, also named Alexander Bell, had forged for himself a reputation as an impressive, if under employed, actor and orator. Endowed with a commanding speaking voice and considerable physical bearing, Alexander Bell sought to unleash in others the full potential of the spoken word. His attention was especially drawn to those for whom the act of speaking presented daunting challenges. His work with such individuals led him to publish writings that included, The Practical Elocutionist and Stammering and Other Impediments of Speech. By 1838, he was regularly being referred to in the London press as "the celebrated Professor of Elocution." The elder Mr. Bell infused in his sons David and Melville a similar interest in the mechanics and methods of vocal communication. David's professional and personal pursuits led him to marriage and a career as a teacher of speech in Dublin, while Melville enthusiastically joined his father in his elocutionary endeavors. Melville's keen interest in speech pathologies was undoubtedly sharpened when he found himself falling in love with a deaf woman he would eventually ask to be his wife. Eliza Grace Symonds, a painter of miniatures, was nearly ten years Melville's senior. Nevertheless, her sweet temper and refined intellect were more than enough to win his lifelong adoration and devotion. Despite being held captive in a world of virtual silence, Eliza Grace Bell developed into a talented pianist whose tenacity and determination to "hear" would especially entrance her second of three sons, Alexander Graham Bell.
A REAL SMART ALECK Young Alexander Graham Bell, Aleck as he was known to his family, took to reading and writing at a precociously young age. Bell family lore told of his insistence upon mailing a letter to a family friend well before he had grasped any understanding of the alphabet. As he matured, Aleck displayed what came to be known as a Bell family trademark--an expressive, flexible, and resonant speaking voice. It was through use of this impressive vocal instrument that Aleck forged a unique bond with his deaf mother. Unlike others, who spoke to Mrs. Bell through her ear tube, Aleck chose to communicate with her by speaking in low, sonorous tones very close to her forehead. Young Aleck surmised that his mother would be able to "hear" him through the vibrations his vocal intonations would make. This early insight would prove significant as Alexander Graham Bell went on to develop more elaborate theories regarding the characteristics of sound waves. It would also lend rationale to Bell's opinions as to how the deaf could be assimilated into a world of sound. Edinburgh, Scotland in the mid-19th-century was brimming with scientific and technological developments. Within this inventive milieu, Alexander Graham Bell played the role of attentive observer and eager participant. One truth seemed inescapable: through technology came betterment. At the age of 14, Bell conceived of a device designed to remove the husks from wheat by combining a nail brush and paddle into a rotary-brushing wheel. While visiting London with his father, Aleck was mesmerized by a demonstration of Sir Charles Wheatstone's "speaking machine." Upon their return to Edinburgh, Melville Bell, Sr. challenged Aleck and his older brother to come up with a model of their own. Working out of their home, the industrious pair created an apparatus consisting of a facsimile mouth, throat, nose, maneuverable tongue, and bellow lungs. What's more, the contraption actually produced human-like sounds. Inspired by this success, Aleck went a step further and succeeded in manipulating the mouth and vocal chords of his Skye terrier so that the dog's growls were heard as words.
"A VERY VALUABLE BLUNDER" With each passing year, Alexander Graham Bell's intellectual horizons broadened. By the time he was 16, he was teaching music and elocution at a boy's boarding school. He and his brothers, Melville and Edward, traveled throughout Scotland impressing audiences with demonstrations of their father's Visible Speech techniques. Combining such ventures with continued study at the University of London, Alexander Graham Bell became intrigued by the writings of German physicist Hermann Von Helmholtz. Von Helmholtz had produced a thesis, On The Sensations of Tone, declaring that vowel sounds could be produced by a combination of electrical tuning forks and resonators. Bell's inability to read German did not deter him from hungrily consuming this information. It did however lead to his making what he would later describe as a "very valuable blunder."
Bell had somehow interpreted Von Helmholtz's findings as stating that vowel sounds could be transmitted over a wire. He would later say of this misunderstanding, "It gave me confidence. If I had been able to read German, I might never have begun my experiments in electricity."
THE DREAMING PLACE In the midst of his early academic and professional success, the young Alexander Graham Bell was buffeted by a series of personal tragedies. Tuberculosis, the scourge of the late 19th century, claimed the lives of both of his brothers within the span of four months. Bell himself was battling the disease when, at age 23, he moved with his parents to Canada. Convalescing in what he called "his dreaming place"--a spacious farmhouse in Brantford, Ontario--Alexander Graham Bell was able to recover in mind and spirit, and dwell on his ever-expanding ambitions.
A TEACHER OF THE DEAF In 1871, Bell began giving instruction in Visible Speech at the Boston School for Deaf Mutes. Attempting to teach deaf children to speak was considered revolutionary, and Bell was not without his detractors as he shunned what he felt were the exclusionary practices of signing and institutionalization. Bell's work with his deaf students in Boston would prove to be a watershed event in his life. One of his pupils, Mabel Hubbard, was the daughter of a man--Gardiner Greene Hubbard-- who would go on to play a vital role in Bell's life and work. While Mabel herself would one day become his wife. Bell felt that a course had been set and he would go on to consider himself, above all else, a teacher of the deaf. In testimony to the effectiveness of his work and generosity of his spirit, no lesser luminary than Helen Keller would dedicate her autobiography to him. THE HARMONIC TELEGRAPH Bell's ideas about transmitting speech electrically came into sharper focus during his days in Boston. As he read extensively on physics and devotedly attended lectures on science and technology, Bell worked to create what he called his "harmonic telegraph." Since Samuel F.B. Morse completed his first telegraph line in 1843, telegraphy had blossomed into a full-fledged industry. This new industry meant nearly instantaneous communication between faraway points. While certainly a technological leap forward, successful telegraphy was nevertheless dependent upon hand-delivery of messages between telegraph stations and individuals. Also, only one message at a time could be transmitted. Drawing parallels between multiple message and multiple notes in a musical chord, Bell arrived at his idea of the "harmonic telegraph." From this idea sprang the invention that made him immortal among inventors--the telephone. A FATEFUL TWANG The chance meeting between Alexander Graham Bell and Thomas Watson at the electrical machine shop of Charles Williams was one of the most fortuitous in technological history. Recognized by his employer as being especially skilled in devising tools that improved the efficiency of various instruments, Watson was assigned to work with many nascent inventors. Alexander Graham Bell was just such an inventor. As the two collaborated on ways to refine Bell's "harmonic telegraph," Bell shared with Watson his vision of what would become the telephone. Watson was intrigued, and a partnership was forged. June 2, 1875 was a milestone day for the team of Bell and Watson. Working in the transmitter room and trying to free a reed that had been too tightly wound to the pole of its electromagnet, Watson produced atwang . Bell, who had been working in the receiving room heard thetwang and came running. Bell surmised the complex overtones and timbre of the twang to be similar to those in the human voice. He was now convinced that his vision of sending speech over a wire was more than just a dream.
PATENT NUMBER 174,465 As Bell raced to perfect his telephone, he was also writing up specifications to be filed with the United States Patent Office in Washington. On March 7, 1876, he was issued patent number 174,465. Meanwhile, Bell had discovered that a wire vibrated by the voice while partially immersed in a conducting liquid, like mercury, could be made to vary its resistance and produce an undulating current. In other words, human speech could be transmitted over a wire.
On March 10, 1876, as he and Mr. Watson set out to test this finding, Bell knocked over what they were using as a transmitting liquid--battery acid. Reacting to the spilled acid, Mr. Bell is alleged to have shouted, "Mr. Watson, come here. I want you!" Exactly what Bell shouted--or whether the spilling of acid ever occurred-- is a matter of some dispute. Its result, however, is not. Watson, working in the next room, heard Bell's voice through the wire. Watson had received the first telephone call, and quickly went to answer it. Seizing upon the opportunity to promote his new invention, Alexander Graham Bell introduced the telephone to the world at the Centennial Exhibition in Philadelphia in 1876. Brazilian Emperor Dom Pedro exclaimed, "My God, it talks," as Bell's mellifluous voice carried Hamlet's soliloquy over the line from the main building one hundred yards away. The success of Bell's telephone was now the talk of the international scientific community. In 1878, Rutherford B. Hayes was the first US president to have a telephone installed in the White House. And to whom did the commander-in-chief place his first call? Alexander Graham Bell, of course, who was waiting for the call some 13 miles away from the White House. The president's first words were said to have been, "Please speak more slowly."
BIG BUSINESS In the wake of Bell's invention of the telephone came an avalanche of patent lawsuits and corporate maneuvers. Western Union Telegraph Company was the titan in the field of telegraphy and was not content to sit on the sidelines as the Bell Telephone Company captured the spotlight. Feverishly working to develop their own telephone technology, Western Union employed two prominent inventors--Thomas A. Edison and Elisha Gray. Looking to protect its patent rights, the Bell Company sued Western Union and won. In the years that followed, the Bell Company (which would eventually become AT&T) would be forced to defend its patent in over 600 legal challenges. In every case, the patent withstood attack thanks largely to Alexander Graham Bell's clear and convincing testimony.
EXPANDING INTERESTS Bell had little interest in playing a day-to-day role in the workings of the company that bore his name. Barely in his thirties, rich and famous, Bell continued to pursue an active life of the mind. His post-telephone inventions included an electric probe used to locate bullets and other metal objects lodged in the body, and the vacuum jacket which, when placed around the chest, administered artificial respiration. Each of these inventions would later be refined and supplanted by other inventors, but Bell's contributions to the world of science and technology never abated. He was a student of nature's mysteries and became fascinated with the notion of motion--in the air and on the water. Working with partners, he experimented with manned kites and hydrofoils. Eager to infuse a love of science and the natural world in others, Bell lent considerable financial and editorial support to both Science magazine and National Geographic. Upon Bell's death on August 2, 1922, the nation's phones stilled their ringing for a silent minute in tribute to the man whose yearning to communicate made them possible.

thenx