脸部出油多用什么护肤品 Alexander Graham Bell

Alexander Graham Bell Alexander Graham Bell British-American inventor Written by Written by Did Hochfelder Associate Professor of History, University at Albany, State University of New York. Author of The Telegraph in America, 1832-1920. Did Hochfelder Fact-checked by Fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they he extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... The Editors of Encyclopaedia Britannica Last Updated: Oct. 18, 2025 •Article History Quick Facts Born: March 3, 1847, Edinburgh, Scotland Died: August 2, 1922, Beinn Bhreagh, Cape Breton Island, Nova Scotia, Canada (aged 75) Founder: AT&T Corporation Awards And Honors: Hall of Fame (1950) Inventions: Graphophone telephone Subjects Of Study: deafness phonograph special education On the Web: Canada's Walk of Fame - Alexander Graham Bell (Oct. 19, 2025) See all related content Top Questions Who was Alexander Graham Bell?

Alexander Graham Bell was an inventor, scientist, and teacher who is best remembered for inventing the telephone. He was born on March 3, 1847, in Scotland, and he and his family moved to England in 1865 and Canada in 1870. A year later Bell moved to the United States, where he taught speech to deaf students and where he also invented and improved a number of electrical technologies. He became a U.S. citizen in 1882 while remaining a British subject; he later moved to Canada and lived there until his death on August 2, 1922.

What did Alexander Graham Bell invent?

Although Alexander Graham Bell is best remembered as the inventor of the telephone, he invented other devices too. Bell developed several sonic technologies, including the photophone (1880) and the Graphophone (1886). He also developed medical technology. After the shooting of U.S. Pres. James A. Garfield in July 1881, Bell teamed up with professor Simon Newcomb of the U.S. Nautical Almanac Office to develop an electrical bullet probe. The pair demonstrated the probe in the autumn of 1881. Bell later shifted his attention to aerial technology. He founded the Aerial Experiment Association in 1907.

How did Alexander Graham Bell’s telephone work?

The first telephone had two parts: a transmitter and a receiver. The transmitter comprised three parts—a drumlike device (a cylinder with a covered end), a needle, and a battery. The covered end of the drumlike device was attached to the needle. The needle was connected by wire to the battery, and the battery was connected by wire to a receiver. When Bell spoke into the open end of the drumlike device, his voice made the paper and needle vibrate. The vibrations were then converted into an electric current which treled along the wire to the receiver.

How the telephone was inventedOverview of the invention of the telephone, with a focus on the work by Alexander Graham Bell.See all videos for this article

Alexander Graham Bell (born March 3, 1847, Edinburgh, Scotland—died August 2, 1922, Beinn Bhreagh, Cape Breton Island, Nova Scotia, Canada) was an inventor, scientist, and teacher of the deaf whose foremost accomplishments, during a life lived in Canada and the United States, were the invention of the telephone (patented in 1876) and the refinement of the phonograph (patented in 1886).

Early life, education, and marriage

Alexander (“Graham” was not added until he was 11) was born to Alexander Melville Bell and Eliza Grace Symonds. His mother was almost deaf, and his father taught elocution to the deaf, influencing Alexander’s later career choice as teacher of the deaf. At age 11 he entered the Royal High School at Edinburgh, but he did not enjoy the compulsory curriculum, and he left school at age 15 without graduating. In 1865 the family moved to London. Alexander passed the entrance examinations for University College London in June 1868 and matriculated there in the autumn. However, he did not complete his studies, because in 1870 the Bell family moved again, this time immigrating to Canada after the deaths of Bell’s younger brother Edward in 1867 and older brother Melville in 1870, both of tuberculosis. The family settled in Brantford, Ontario, but in April 1871 Alexander moved to Boston, where he taught at the Boston School for Deaf Mutes. He also taught at the Clarke School for the Deaf in Northampton, Massachusetts, and at the American School for the Deaf in Hartford, Connecticut.

One of Bell’s students was Mabel Hubbard, daughter of Gardiner Greene Hubbard, a founder of the Clarke School. Mabel had become deaf at age five as a result of a near-fatal bout of scarlet fever. Bell began working with her in 1873, when she was 15 years old. Despite a 10-year age difference, they fell in love and were married on July 11, 1877. They had four children, Elsie (1878–1964), Marian (1880–1962), and two sons who died in infancy.

Britannica Quiz What Very Big Thing Happened on This Day? Development of the telephone Thomas A. Watson describing invention of the telephoneThomas A. Watson, assistant to Alexander Graham Bell, discussing the birth of the telephone, including the first words spoken.

While pursuing his teaching profession, Bell also began researching methods to transmit several telegraph messages simultaneously over a single wire—a major focus of telegraph innovation at the time and one that ultimately led to Bell’s invention of the telephone. In 1868 Joseph Stearns had invented the duplex, a system that transmitted two messages simultaneously over a single wire. Western Union Telegraph Company, the dominant firm in the industry, acquired the rights to Stearns’s duplex and hired the noted inventor Thomas Edison to devise as many multiple-transmission methods as possible in order to block competitors from using them. Edison’s work culminated in the quadruplex, a system for sending four simultaneous telegraph messages over a single wire. Inventors then sought methods that could send more than four; some, including Bell and his great rival Elisha Gray, developed designs capable of subdividing a telegraph line into 10 or more channels. These so-called harmonic telegraphs used reeds or tuning forks that responded to specific acoustic frequencies. They worked well in the laboratory but proved unreliable in service.

telephone: Alexander Graham Bell's sketch of a telephoneAlexander Graham Bell's sketch of a telephone. He filed the patent for his telephone at the U.S. Patent Office on February 14, 1876—just two hours before a rival, Elisha Gray, filed a declaration of intent to file a patent for a similar device.

A group of investors led by Gardiner Hubbard wanted to establish a federally chartered telegraph company to compete with Western Union by contracting with the Post Office to send low-cost telegrams. Hubbard saw great promise in the harmonic telegraph and backed Bell’s experiments. Bell, however, was more interested in transmitting the human voice. Finally, he and Hubbard worked out an agreement that Bell would devote most of his time to the harmonic telegraph but would continue developing his telephone concept.

From harmonic telegraphs transmitting musical tones, it was a short conceptual step for both Bell and Gray to transmit the human voice. Bell filed a patent describing his method of transmitting sounds on February 14, 1876, just hours before Gray filed a ceat (a statement of concept) on a similar method. On March 7, 1876, the Patent Office awarded Bell what is said to be one of the most valuable patents in history. It is most likely that both Bell and Gray independently devised their telephone designs as an outgrowth of their work on harmonic telegraphy. However, the question of priority of invention between the two has been controversial from the very beginning.

1 of 2Alexander Graham BellAlexander Graham Bell, inventor who patented the telephone in 1876, lecturing at Salem, Massachusetts (top), while friends in his study at Boston listen to his lecture via telephone, February 12, 1877.2 of 2Alexander Graham Bell and the New York City–Chicago telephone linkAlexander Graham Bell, who patented the telephone in 1876, inaugurating the 1,520-km (944-mile) telephone link between New York City and Chicago on October 18, 1892.

Despite hing the patent, Bell did not he a fully functioning instrument. He first produced intelligible speech on March 10, 1876, when he summoned his laboratory assistant, Thomas A. Watson, with words that Bell transcribed in his lab notes as “Mr. Watson—come here—I want to see you.” Over the next few months, Bell continued to refine his instrument to make it suitable for public exhibition. In June he demonstrated his telephone to the judges of the Philadelphia Centennial Exhibition, a test witnessed by Brazil’s Emperor Pedro II and the celebrated Scottish physicist Sir William Thomson. In August of that year, he was on the receiving end of the first one-way long-distance call, transmitted from Brantford to nearby Paris, Ontario, over a telegraph wire.

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Gardiner Hubbard organized a group that established the Bell Telephone Company in July 1877 to commercialize Bell’s telephone. Bell was the company’s technical adviser until he lost interest in telephony in the early 1880s. Although his invention rendered him independently wealthy, he sold off most of his stock holdings in the company early and did not profit as much as he might he had he retained his shares. Thus, by the mid-1880s his role in the telephone industry was marginal.

Improvements to the phonograph How a Graphophone records and plays soundThe vertical “hill-and-dale” groove, as played by a Columbia Graphophone, c. 1902. Patented by Charles Sumner Tainter, Chichester A. Bell, and Alexander Graham Bell in 1886, this vertically undulating groove, cut into a wax surface, was the most successful method employed in cylinder sound recording.See all videos for this article

By that time, Bell had developed a growing interest in the technology of sound recording and playback. Although Edison had invented the phonograph in 1877, he soon turned his attention to other technologies, especially electric power and lighting, and his machine, which recorded and reproduced sound on a rotating cylinder wrapped in tinfoil, remained an unreliable and cumbersome device. In 1880 the French government awarded Bell the Volta Prize, given for achievement in electrical science. Bell used the prize money to set up his Volta Laboratory, an institution devoted to studying deafness and improving the lives of the deaf, in Washington, D.C. There he also devoted himself to improving the phonograph. By 1885 Bell and his colleagues (his cousin Chichester A. Bell and the inventor Charles Sumner Tainter) had a design fit for commercial use that featured a removable cardboard cylinder coated with mineral wax. They called their device the Graphophone and applied for patents, which were granted in 1886. The group formed the Volta Graphophone Company to produce their invention. Then in 1887 they sold their patents to the American Graphophone Company, which later evolved into the Columbia Phonograph Company. Bell used his proceeds from the sale to endow the Volta Laboratory.

The photophone and the electrical bullet probe

Bell undertook two other noteworthy research projects at the Volta Laboratory. In 1880 he began research on using light as a means to transmit sound. In 1873 British scientist Willoughby Smith discovered that the element selenium, a semiconductor, varied its electrical resistance with the intensity of incident light. Bell sought to use this property to develop the photophone, an invention he regarded as at least equal to his telephone. He was able to demonstrate that the photophone was technologically feasible, but it did not develop into a commercially viable product. Nevertheless, it contributed to research into the photovoltaic effect that had practical applications later in the 20th century.

Bell’s other major undertaking was the development of an electrical bullet probe, an early version of the metal detector, for surgical use. The origin of this effort was the shooting of U.S. President James A. Garfield in July 1881. A bullet lodged in the president’s back, and doctors were unable to locate it through physical probing. Bell decided that a promising approach was to use an induction balance, a by-product of his research on canceling out electrical interference on telephone wires. Bell determined that a properly configured induction balance would emit a tone when a metal object was brought into proximity with it. At the end of July, he began searching for Garfield’s bullet, but to no ail. Despite Garfield’s death in September, Bell later successfully demonstrated the probe to a group of doctors. Surgeons adopted it, and it was credited with sing lives during the Boer War (1899–1902) and World War I (1914–18).

Later years: iation experiments and scientific advocacy

In September 1885 the Bell family vacationed in Nova Scotia, Canada, and immediately fell in love with the climate and landscape. The following year, Bell bought 50 acres of land near the village of Baddeck on Cape Breton Island and began constructing an estate he called Beinn Bhreagh, Scots Gaelic for “Beautiful Mountain.” The Scottish-born inventor had been an American citizen since 1882, but the Canadian estate became the family’s summer retreat and later permanent home.

“Though I cannot claim to be a Canadian, except that I he a warm spot in my heart for Canada, I do want Canada to he the benefit of these Canadian boys.” —Alexander Graham Bell in support of Canadian iation pioneers, Canadian Club of Ottawa, March 27, 1909

During the 1890s Bell shifted his attention to heier-than-air flight. Starting in 1891, inspired by the research of American scientist Samuel Pierpont Langley, he experimented with wing shapes and propeller blade designs. He continued his experiments even after Wilbur and Orville Wright made the first successful powered, controlled flight in 1903. In 1907 Bell founded the Aerial Experiment Association, which made significant progress in aircraft design and control and contributed to the career of pioneer iator Glenn Hammond Curtiss.

Throughout his life, Bell sought to foster the advance of scientific knowledge. He supported the journal Science, which later became the official publication of the American Association for the Advancement of Science. He succeeded his father-in-law, Gardiner Hubbard, as president of the National Geographic Society (1898–1903). In 1903 his son-in-law, Gilbert H. Grosvenor, became editor in chief of the National Geographic Magazine, and Bell encouraged Grosvenor to make the magazine a more popular publication through more photographs and fewer scholarly articles. Bell died at his Nova Scotia estate, where he was buried.

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