Inventions and Discovery----------Telephone


A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are not in the same vicinity of each other to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals suitable for transmission via cables or other transmission media over long distances, and replays such signals simultaneously in audible form to its user. The word telephone has been adapted into the vocabulary of many languages.

First patented in 1876 by Alexander Graham Bell and further developed by many others, the telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones rapidly became indispensable to businesses, government, and households, and are today some of the most widely used small appliances.


Credit for the invention of the electric telephone is frequently disputed. As with other influential inventions such as radio, television, the light bulb, and the computer, several inventors pioneered experimental work on voice transmission over a wire and improved on each other's ideas. New controversies over the issue still arise from time to time. Charles Bourseul, Antonio Meucci, Johann Philipp Reis, Alexander Graham Bell, and Elisha Gray, amongst others, have all been credited with the invention of the telephone.

In 1854 the French engineer Charles Bourseul wrote the first design of a telephone in a public memorandum, but Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. The Bell patents were forensically victorious and commercially decisive. That first patent by Bell was the master patent of the telephone, from which other patents for electric telephone devices and features flowed.

In 1876, shortly after the telephone was invented, Hungarian engineer Tivadar Puskás invented the telephone switch, which allowed for the formation of telephone exchanges, and eventually networks.

Early development

1844 — Innocenzo Manzetti first mooted the idea of a "speaking telegraph" or telephone. Use of the 'speaking telegraph' and 'sound telegraph' monikers would eventually be replaced by the newer, distinct name, 'telephone'.

    26 August 1854 — Charles Bourseul published an article in the magazine L'Illustration (Paris): "Transmission électrique de la parole" (electric transmission of speech), describing a 'make-and-break' type telephone transmitter later created by Johann Reis.

    26 October 1861 — Johann Philipp Reis (1834–1874) publicly demonstrated the Reis telephone before the Physical Society of Frankfurt.

    22 August 1865, La Feuille d'Aoste reported "It is rumored that English technicians to whom Mr. Manzetti illustrated his method for transmitting spoken words on the telegraph wire intend to apply said invention in England on several private telegraph lines". However telephones would not be demonstrated there until 1876, with a set of telephones from Bell.

    28 December 1871 — Antonio Meucci files patent caveat No. 3335 in the U.S. Patent Office titled "Sound Telegraph", describing communication of voice between two people by wire. A 'patent caveat' was not an invention patent award, but only an unverified notice filed by an individual that he or she intends to file a regular patent application in the future.

    1874 — Meucci, after having renewed the caveat for two years does not renew it again, and the caveat lapses.

    6 April 1875 — Bell's U.S. Patent 161,739 "Transmitters and Receivers for Electric Telegraphs" is granted. This uses multiple vibrating steel reeds in make-break circuits.

    11 February 1876 — Gray invents a liquid transmitter for use with a telephone but does not build one.

    14 February 1876 — Elisha Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.

    14 February 1876 — Alexander Bell applies for the patent "Improvements in Telegraphy", for electromagnetic telephones using what is now called amplitude modulation (oscillating current and voltage) but which he referred to as "undulating current".

    19 February 1876 — Gray is notified by the U.S. Patent Office of an interference between his caveat and Bell's patent application. Gray decides to abandon his caveat.

    7 March 1876 — Bell's U.S. patent 174,465 "Improvement in Telegraphy" is granted, covering "the method of, and apparatus for, transmitting vocal or other sounds telegraphically … by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound."

    10 March 1876 — The first successful telephone transmission of clear speech using a liquid transmitter when Bell spoke into his device, "Mr. Watson, come here, I want to see you." and Watson heard each word distinctly.

    30 January 1877 — Bell's U.S. patent 186,787 is granted for an electromagnetic telephone using permanent magnets, iron diaphragms, and a call bell.

    27 April 1877 — Edison files for a patent on a carbon (graphite) transmitter. The patent 474,230 was granted 3 May 1892, after a 15 year delay because of litigation. Edison was granted patent 222,390 for a carbon granules transmitter in 1879.


By 1874, Bell's initial work on the harmonic telegraph had entered a formative stage with progress it made both at his new Boston "laboratory" (a rented facility) as well as at his family home in Canada a big success.While working that summer in Brantford, Bell experimented with a "phonautograph", a pen-like machine that could draw shapes of sound waves on smoked glass by tracing their vibrations. Bell thought it might be possible to generate undulating electrical currents that corresponded to sound waves. Bell also thought that multiple metal reeds tuned to different frequencies like a harp would be able to convert the undulating currents back into sound. But he had no working model to demonstrate the feasibility of these ideas.

In 1874, telegraph message traffic was rapidly expanding and in the words of Western Union President William Orton, had become "the nervous system of commerce". Orton had contracted with inventors Thomas Edison and Elisha Gray to find a way to send multiple telegraph messages on each telegraph line to avoid the great cost of constructing new lines.When Bell mentioned to Gardiner Hubbard and Thomas Sanders that he was working on a method of sending multiple tones on a telegraph wire using a multi-reed device, the two wealthy patrons began to financially support Bell's experiments.Patent matters would be handled by Hubbard's patent attorney, Anthony Pollok.

In March 1875, Bell and Pollok visited the famous scientist Joseph Henry, who was then director of the Smithsonian Institution, and asked Henry's advice on the electrical multi-reed apparatus that Bell hoped would transmit the human voice by telegraph. Henry replied that Bell had "the germ of a great invention". When Bell said that he did not have the necessary knowledge, Henry replied, "Get it!" That declaration greatly encouraged Bell to keep trying, even though he did not have the equipment needed to continue his experiments, nor the ability to create a working model of his ideas. However, a chance meeting in 1874 between Bell and Thomas A. Watson, an experienced electrical designer and mechanic at the electrical machine shop of Charles Williams, changed all that.

With financial support from Sanders and Hubbard, Bell hired Thomas Watson as his assistant,and the two of them experimented with acoustic telegraphy. On June 2, 1875, Watson accidentally plucked one of the reeds and Bell, at the receiving end of the wire, heard the overtones of the reed; overtones that would be necessary for transmitting speech. That demonstrated to Bell that only one reed or armature was necessary, not multiple reeds. This led to the "gallows" sound-powered telephone, which could transmit indistinct, voice-like sounds, but not clear speech.


As is sometimes common in scientific discoveries, simultaneous developments can occur, as evidenced by a number of inventors who were at work on the telephone. Over a period of 18 years, the Bell Telephone Company faced 587 court challenges to its patents, including five that went to the U.S. Supreme Court, but none was successful in establishing priority over the original Bell patent and the Bell Telephone Company never lost a case that had proceeded to a final trial stage. Bell's laboratory notes and family letters were the key to establishing a long lineage to his experiments. The Bell company lawyers successfully fought off myriad lawsuits generated initially around the challenges by Elisha Gray and Amos Dolbear. In personal correspondence to Bell, both Gray and Dolbear had acknowledged his prior work, which considerably weakened their later claims.

                                              Alexander Graham Bell's telephone patent drawing, March 7, 1876.

On January 13, 1887, the U,S. Government moved to annul the patent issued to Bell on the grounds of fraud and misrepresentation. After a series of decisions and reversals, the Bell company won a decision in the Supreme Court, though a couple of the original claims from the lower court cases were left undecided. By the time that the trial wound its way through nine years of legal battles, the U.S. prosecuting attorney had died and the two Bell patents (No. 174,465 and dated March 7, 1876 and No. 186,787 dated January 30, 1877) were no longer in effect, although the presiding judges agreed to continue the proceedings due to the case's importance as a "precedent". With a change in administration and charges of conflict of interest (on both sides) arising from the original trial, the US Attorney General dropped the lawsuit on November 30, 1897 leaving several issues undecided on the merits.

During a deposition filed for the 1887 trial, Italian inventor Antonio Meucci also claimed to have created the first working model of a telephone in Italy in 1834. In 1886, in the first of three cases in which he was involved, Meucci took the stand as a witness in the hopes of establishing his invention's priority. Meucci's evidence in this case was disputed due to a lack of material evidence for his inventions as his working models were purportedly lost at the laboratory of American District Telegraph (ADT) of New York, which was later incorporated as a subsidiary of Western Union in 1901.Meucci's work, like many other inventors of the period, was based on earlier acoustic principles and despite evidence of earlier experiments, the final case involving Meucci was eventually dropped upon Meucci's death.However, due to the efforts of Congressman Vito Fossella, the U.S. House of Representatives on June 11, 2002 stated that Meucci's "work in the invention of the telephone should be acknowledged", even though this did not put an end to a still contentious issue. Some modern scholars do not agree with the claims that Bell's work on the telephone was influenced by Meucci's inventions. 

                                 Bell at the opening of the long-distance line from New York to Chicago in 1892.

The value of the Bell patent was acknowledged throughout the world, and patent applications were made in most major countries, but when Bell had delayed the German patent application, the electrical firm of Siemens & Halske (S&H) managed to set up a rival manufacturer of Bell telephones under their own patent. The Siemens company produced near-identical copies of the Bell telephone without having to pay royalties. The establishment of the International Bell Telephone Company in Brussels, Belgium in 1880, as well as a series of agreements in other countries eventually consolidated a global telephone operation. The strain put on Bell by his constant appearances in court, necessitated by the legal battles, eventually resulted in his resignation from the company.


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