Invention of the telephone - AbsoluteAstronomy.com

The invention of the telephone is the culmination of work done by many individuals, the history of which involves a collection of claims and counterclaims. The development of the modern telephone

Telephone

The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

involved an array of lawsuits founded upon the patent claims

Claim (patent)

Patent claims are the part of a patent or patent application that defines the scope of protection granted by the patent. The claims define, in technical terms, the extent of the protection conferred by a patent, or the protection sought in a patent application...

of several individuals. This article covers the early years 1844–1898, from conception of the idea of an electric voice-transmission device, failed attempts to use "make-and-break" current, successful experiments with electromagnetic devices by Alexander Bell and Thomas Watson, to commercially successful telephones in the late 19th century.

The origins of the telephone date back to the non-electrical string telephone or "lover's telephone" that has been known for centuries, comprising two diaphragm

Diaphragm (acoustics)

In the field of acoustics, a diaphragm is a transducer intended to faithfully inter-convert mechanical motion and sound. It is commonly constructed of a thin membrane or sheet of various materials. The varying air pressure of the sound waves imparts vibrations onto the diaphragm which can then be...

s connected by a taut string or wire. Sound waves are carried as mechanical vibrations along the string or wire from one diaphragm to the other. The classic example is the tin can telephone

Tin can telephone

A tin can telephone is a type of voice-transmitting device made up of two tin cans, paper cups or similarly shaped items attached to either end of a taut string or wire.- How it works :...

, a children's toy made by connecting the two ends of a string to the bottoms of two metal cans, paper cups or similar items. The essential idea of this toy was that a diaphragm can collect voice sounds from the air, as in the ear, and a string or wire can transmit such collected voice sounds for reproduction at a distance.

Charles Grafton Page

American Charles Grafton Page

Charles Grafton Page

Charles Grafton Page was an American electrical experimenter and inventor, physician, patent examiner, patent advocate, and professor of chemistry....

(1812-1868) in 1837 passed an electric current through a coil of wire placed between the poles of a horseshoe magnet. He observed that connecting and disconnecting the current caused a ringing sound in the magnet. He called this effect "galvanic music".

Innocenzo Manzetti

Innocenzo Vincenzo Bartolomeo Luigi Carlo Manzetti was an Italian inventor born in Aosta. Following his primary school studies he went to the Jesuit-run Saint Bénin Boarding School and then on to Turin where he was awarded a diploma in land surveying before returning to Aosta.- Automaton :In 1849...

considered the idea of a telephone as early as 1844, and may have made one in 1864, as an enhancement to an automaton built by him in 1849.

Charles Bourseul

In 1854 Charles Bourseul

Charles Bourseul

Charles Bourseul was a pioneer in development of the "make and break" telephone about 20 years before Bell made a practical telephone....

, a French telegrapher, published a plan for conveying sounds and even speech by electricity in the magazine L'Illustration

L'Illustration

L'Illustration was a weekly French newspaper published in Paris. It was founded by Edouard Charton; the first issue was published on March 4, 1843....

(Paris). Bourseul's ideas were also published in Didaskalia (Frankfurt am Main) on September 28, 1854:
"Suppose", he explained, “that a man speaks near a movable disc sufficiently flexible to lose none of the vibrations of the voice; that this disc alternately makes and breaks the currents from a battery: you may have at a distance another disc which will simultaneously execute the same vibrations.... It is certain that, in a more or less distant future, speech will be transmitted by electricity. I have made experiments in this direction; they are delicate and demand time and patience, but the approximations obtained promise a favourable result."

This make-or-break signaling was able to transmit tones and some vowels, but since it did not follow the analog shape of the sound wave (the contact was pure digital, on or off) it could not transmit consonants, or complex sounds. Bourseul's phrase "make and break the current" was inaccurately applied to later work by Philipp Reis who successfully transmitted faint voice sounds with unbroken current.

Johann Philipp Reis

In 1860 Johann Philipp Reis was the first who produced a functioning electromagnetic device that could transmit musical notes, indistinct speech, and occasionally distinct speech by means of electric signals. Reis also introduced the term "telephon" for his device. The first sentence spoken on it was "Das Pferd frisst keinen Gurkensalat" (the horse doesn't eat cucumber salad). In the Reis transmitter, a diaphragm was attached to a needle that pressed against a metal contact. This resembled the make-or-break design of Bourseul, although Reis used the term "molecular motion" (molekulare Bewegung) to describe the contact points of his transmitter. The Reis transmitter was very difficult to operate, since the relative position of the needle and the contact were critical to the device's operation. This can be called a "telephone", since it did transmit voice sounds over distance, but was hardly a commercially practical telephone in the modern sense, as it failed to reliably transmit a good copy of any supplied sound.

Thomas Edison tested the Reis equipment and found that "single words, uttered as in reading, speaking and the like, were perceptible indistinctly, notwithstanding here also the inflections of the voice, the modulations of interrogation, wonder, command, etc., attained distinct expression."

Prior to 1947, the Reis device was tested by the British company Standard Telephones and Cables

Standard Telephones and Cables

Standard Telephones and Cables Ltd was a British telephone, telegraph, radio, telecommunications and related equipment R&D manufacturer. During its history STC invented and developed several groundbreaking new technologies including PCM and optical fibres.The company began life in London as...

(STC). The results also confirmed it could faintly transmit and receive speech. At the time STC was bidding for a contract with Alexander Graham Bell's American Telephone and Telegraph Company

AT&T

AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...

, and the results were covered up by STC's chairman Sir Frank Gill to maintain Bell's reputation.

Antonio Meucci

An early voice communicating device was invented around 1854 by Antonio Meucci

Antonio Meucci

Antonio Santi Giuseppe Meucci was an Italian inventor, a compatriot of revolutionary Giuseppe Garibaldi. He was best known for developing a voice communication apparatus which several sources credit as the first telephone....

, who called it a telettrofono. In 1871 Meucci filed a caveat

Patent caveat

A patent caveat was a legal document filed with the United States Patent Office. Caveats were instituted by the US Patent Act of 1836, but were discontinued in 1909. A caveat was like a patent application with a description of an invention and drawings, but without claims. It was an official...

at the US Patent Office. His caveat describes his invention, but does not mention a diaphragm, electromagnet, conversion of sound into electrical waves, conversion of electrical waves into sound, or other essential features of an electromagnetic telephone.

The first American demonstration of Meucci's invention took place in Staten Island

Staten Island

Staten Island is a borough of New York City, New York, United States, located in the southwest part of the city. Staten Island is separated from New Jersey by the Arthur Kill and the Kill Van Kull, and from the rest of New York by New York Bay...

, New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

in 1854. In 1860, a description of it was reportedly published in an Italian-language New York newspaper, although no known copy of that newspaper issue or article survived to the present day. Meucci claimed to have invented a paired electro-magnetic transmitter and receiver, where the motion of a diaphragm modulated a signal in a coil by moving an electromagnet, although this was not mentioned in his 1871 U.S. patent caveat. A further discrepancy observed was that the device described in the 1871 caveat employed only a single conduction wire, with the telephone's transmitter-receivers being insulated from a 'ground return' path.

In the 1880s Meucci was credited with the early invention of inductive loading of telephone wires to increase long-distance signals. Unfortunately, serious burns from an accident, a lack of English, and poor business abilities resulted in Meucci failing to develop his inventions commercially in America. Meucci demonstrated some sort of instrument in 1849 in Havana, Cuba, but the evidence is clear that this was not an electromagnetic telephone and may have been a variant of a string telephone

Tin can telephone

A tin can telephone is a type of voice-transmitting device made up of two tin cans, paper cups or similarly shaped items attached to either end of a taut string or wire.- How it works :...

that used wire. Meucci has been further credited with invention of an anti-sidetone

Sidetone

Sidetone is audible feedback to someone who is speaking. The term is most used in telecommunication contexts.-Telephony:In telephony, sidetone is the effect of sound that is picked up by the telephone's mouthpiece and in real-time introduced at a low level into the earpiece of the same handset,...

circuit. However, examination showed that his solution to sidetone was to maintain two separate telephone circuits, and thus use twice as many transmission wires. The anti-sidetone circuit later introduced by Bell Telephone instead cancelled sidetone through a feedback process.

An American District Telegraph

ADT Security Services

ADT Security Services, originally American District Telegraph, now also known as simply ADT, is a division of Tyco International and a worldwide supplier of electronic security systems, fire alarm systems, communication systems, and integrated building management systems.-History:There were many...

(ADT) laboratory reportedly lost some of Meucci's working models, his wife reportedly disposed of others and Meucci, who sometimes lived on public assistance, chose not to renew his 1871 teletrofono patent caveat

Patent caveat

after 1874.

Meucci was recognized for his pioneering work on the telephone by the United States House of Representatives

United States House of Representatives

The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...

in 2002. The resolution stated that "if Meucci had been able to pay the $10 fee to maintain the caveat after 1874, no patent could have been issued to Bell." No such patent could have issued to Bell in March 1876. If Meucci had renewed his caveat, he would have been given an opportunity to prove to the examiner that the device described in his caveat was the electromagnetic telephone described in Bell's patent application.

The Meucci resolution by the US Congress was promptly followed by a Canada legislative motion by Canada's 37th Parliament

37th Canadian Parliament

The 37th Canadian Parliament was in session from January 29, 2001, until May 23, 2004. The membership was set by the 2000 federal election on November 27, 2000, and it changed only somewhat due to resignations and by-elections until it was dissolved prior to the 2004 election.It was controlled by...

, declaring Alexander Graham Bell

Alexander Graham Bell

Alexander Graham Bell was an eminent scientist, inventor, engineer and innovator who is credited with inventing the first practical telephone....

as the inventor of the telephone. Others in Canada disagreed with the Congressional resolution, some of whom provided criticisms of both its accuracy and intent.

Chronology of Meucci's invention

An Italian researcher in telecommunications, engineer Basilio Catania, and the Italian Society of Electrotechnics, "Federazione Italiana di Elettrotecnica", have devoted a Museum to Antonio Meucci, constructing a chronology of his invention of the telephone and tracing the history of the two legal trials involving Meucci and Alexander Graham Bell. Both claim that Meucci was the real inventor of the telephone, and base their argument on the reconstructed evidence. What follows, if not otherwise stated, is a résumé

Résumé

A résumé is a document used by individuals to present their background and skillsets. Résumés can be used for a variety of reasons but most often to secure new employment. A typical résumé contains a summary of relevant job experience and education...

of their historic reconstruction.

In 1834 Meucci constructed a kind of acoustic telephone as a way to communicate between the stage and control room at the theatre "Teatro della Pergola" in Florence. This telephone is constructed on the model of pipe-telephones on ships and is still working.
In 1848 Meucci developed a popular method of using electric shocks to treat rheumatism
Rheumatism
Rheumatism or rheumatic disorder is a non-specific term for medical problems affecting the joints and connective tissue. The study of, and therapeutic interventions in, such disorders is called rheumatology.-Terminology:...

. He used to give his patients two conductors linked to 60 Bunsen batteries and ending with a cork. He also kept two conductors linked to the same Bunsen batteries. He used to sit in his laboratory, while the Bunsen batteries were placed in a second room and his patients in a third room. In 1849 while providing a treatment to a patient with a 114V electrical discharge, in his laboratory Meucci heard his patient's scream through the piece of copper wire that was between them, from the conductors he was keeping near his ear. His intuition was that the "tongue" of copper wire was vibrating just like a leave of an electroscope; which means that there was an electrostatic effect. In order to continue the experiment without hurting his patient, Meucci covered the copper wire with a piece of paper. Through this device he heard inarticulated human voice. He called this device "telegrafo parlante" (litt. "talking telegraph").
On the basis of this prototype, Meucci worked on more than 30 kinds of sound transmitting devices inspired by the telegraph model as did other pioneers of the telephone, such as Charles Bourseul
Charles Bourseul
Charles Bourseul was a pioneer in development of the "make and break" telephone about 20 years before Bell made a practical telephone....

, Philipp Reis, Innocenzo Manzetti
Innocenzo Manzetti
Innocenzo Vincenzo Bartolomeo Luigi Carlo Manzetti was an Italian inventor born in Aosta. Following his primary school studies he went to the Jesuit-run Saint Bénin Boarding School and then on to Turin where he was awarded a diploma in land surveying before returning to Aosta.- Automaton :In 1849...

and others. Meucci later claimed that he did not think about transmitting voice by using the principle of the telegraph "make-and-break" method, but he looked for a "continuous" solution that did not interrupt the electric current.
In 1856 Meucci later claimed that he constructed the first electromagnetic telephone, made of an electromagnet with a nucleus in the shape of a horseshoe bat, a diaphragm of animal skin, stiffened with potassium dichromate and keeping a metal disk stuck in the middle. The instrument was hosted in a cylindrical carton box. He said he constructed this as a way to connect his second-floor bedroom to his basement laboratory, and thus communicate with his wife who was an invalid
Patient
A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....

.
Meucci separated the two directions of transmission in order to eliminate the so-called "local effect", adopting what we would call today a 4-wire-circuit. He constructed a simple calling system with a telegraphic manipulator which short-circuited the instrument of the calling person, producing in the instrument of the called person a succession of impulses (clicks), much more intense than those of normal conversation. As he was aware that his device required a bigger band than a telegraph, he found some means to avoid the so-called "skin effect" through superficial treatment of the conductor or by acting on the material (copper instead of iron). He successfully used an insulated copper plait, thus anticipating the litz wire used by Nikola Tesla
Nikola Tesla
Nikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer...

in RF coils.
In 1864 Meucci later claimed that he realized his "best device", using an iron diaphragm with optimized thickness and tightly clamped along its rim. The instrument was housed in a shaving-soap box, whose cover clamped the diaphragm.
In August 1870, Meucci later claimed that he obtained transmission of articulate human voice at a mile distance by using as a conductor a copper plait insulated by cotton. He called his device "teletrofono". Drawings and notes by Antonio Meucci dated September 27, 1870 show coils of wire on long distance telephone lines. The painting made by Nestore Corradi :it:Nestore Corradi in 1858 mentions the sentence "Electric current from the inductor pipe"

The above information was published in the Scientific American Supplement No. 520, December 19, 1885, based on reconstructions produced in 1885, for which there was no contemporary pre-1875 evidence. Meucci's 1871 caveat

Patent caveat

did not mention any of the telephone features later credited to him by his lawyer, and which were published in that Scientific American Supplement, a major reason for the loss of the 'Bell v. Globe and Meucci' patent infringement court case, which was decided against him. See Antonio Meucci – Patent caveat, for the full printed text of his 1871 teletrofono patent caveat.

Cromwell Varley

Around 1870 Mr. C. F. Varley

C. F. Varley

Cromwell Fleetwood Varley was an English engineer, particularly associated with the development of the electric telegraph and the transatlantic telegraph cable.-Family:...

, F.R.S., a well-known English electrician, patented a number of variations on the audio telegraph based on Reis' work. He never claimed or produced a device capable of transmitting speech, only pure tones.

Poul la Cour

Around 1874 Poul la Cour

Poul la Cour

Poul la Cour was a Danish scientist, inventor and educationalist. Today la Cour is especially recognized for his early work on wind power, both experimental work on aerodynamics and practical implementation of wind power plants. He worked most of his life at Askov Folk High School where he...

, a Danish

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

inventor, experimented with audio telegraphs on a telegraph line between Copenhagen

Copenhagen

Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...

and Fredericia

Fredericia

Fredericia is a town located in Fredericia municipality in the eastern part of the Jutland peninsula in Denmark, in a sub-region known locally as Trekanten, or The Triangle...

in Jutland

Jutland

Jutland , historically also called Cimbria, is the name of the peninsula that juts out in Northern Europe toward the rest of Scandinavia, forming the mainland part of Denmark. It has the North Sea to its west, Kattegat and Skagerrak to its north, the Baltic Sea to its east, and the Danish–German...

. His experiment used a vibrating tuning-fork to interrupt the line current, which, after traversing the line passed through an electromagnet

Electromagnet

An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. The magnetic field disappears when the current is turned off...

that acted upon the tines of another tuning-fork, making it resonate at the same pitch of the transmitting fork. Moreover, the hums were also recorded on paper by turning the electromagnetic receiver into a relay

Relay

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...

, which actuated a Morse code

Morse code

Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...

printer by means of a local battery

Battery (electricity)

An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...

. Again, la Cour made no claims of transmitting voice, only pure tones.

Daniel Drawbaugh

Daniel Drawbaugh was a purported inventor of the telephone for which he sought a patent in 1880. His claims were contested by the Bell Telephone Company, which won a court decision in 1888....

, a bearded rustic tinkerer from Pennsylvania, claimed to have invented a telephone using a teacup as transmitter as early as 1867, and to have applied for a patent about 1880, but his case was dismissed in the 1880-88 legal challenge to Bell (see The Telephone Cases

The Telephone Cases

The Telephone Cases were a series of U.S. court cases in the 1870s and 1880s related to the invention of the telephone, which culminated in the 1888 decision of the United States Supreme Court upholding the priority of the patents belonging to Alexander Graham Bell...

), and also in 1896.

Elisha Gray

Main article: Elisha Gray
Elisha Gray
Elisha Gray was an American electrical engineer who co-founded the Western Electric Manufacturing Company...

, See also: Elisha Gray and Alexander Bell telephone controversy

Elisha Gray

Elisha Gray was an American electrical engineer who co-founded the Western Electric Manufacturing Company...

, of Highland Park, Illinois

Highland Park, Illinois

Highland Park is a suburban municipality in Lake County, Illinois, United States, about north of downtown Chicago. As of 2009, the population is 33,492. Highland Park is one of several municipalities located on the North Shore of the Chicago Metropolitan Area.-Overview:Highland Park was founded...

(near Chicago) also devised a tone telegraph of this kind about the same time as La Cour. In Gray's tone telegraph, several vibrating steel reeds tuned to different frequencies interrupted the current, which at the other end of the line passed through electromagnets and vibrated matching tuned steel reeds near the electromagnet poles. Gray's 'harmonic telegraph,' with vibrating reeds, was used by the Western Union Telegraph Company. Since more than one set of vibration frequencies — that is to say, more than one musical tone — can be sent over the same wire simultaneously, the harmonic telegraph can be utilised as a 'multiplex' or many-ply telegraph, conveying several messages through the same wire at the same time. Each message can either be read by an operator by the sound, or from different tones read by different operators, or a permanent record can be made by the marks drawn on a ribbon of travelling paper by a Morse recorder. On 27 July 1875, Gray was granted U.S. patent 166,096 for "Electric Telegraph for Transmitting Musical Tones" (the harmonic telegraph).

On 14 February 1876, Gray filed a patent caveat

Patent caveat

for a telephone on the very same day in 1876 as did Bell's lawyer. The water transmitter

Water microphone

A water microphone or water transmitter is based on Ohm's law that current in a wire varies inversely with the resistance of the circuit. The sound waves from a human voice cause a diaphragm to vibrate which causes a needle or rod to vibrate up and down in water that has been made conductive by a...

described in Gray's caveat was strikingly similar to the experimental telephone transmitter tested by Bell on March 10, 1876, a fact which raised questions about whether Bell (who knew of Gray) was inspired by Gray's design or vice versa. Although Bell did not use Gray's water transmitter in later telephones, evidence suggests that Bell's lawyers may have obtained an unfair advantage over Gray.

Alexander Graham Bell

Alexander Graham Bell was an eminent scientist, inventor, engineer and innovator who is credited with inventing the first practical telephone....

is commonly credited as the inventor of the first practical telephone. The classic story of his crying out "Watson, come here! I want to see you!" is a well known part of American history. Bell was the first to obtain a patent, in 1876, for an "apparatus for transmitting vocal or other sounds telegraphically", after experimenting with many primitive sound transmitters and receivers. Bell was also an astute and articulate business man with influential and wealthy friends.

As Professor of Vocal Physiology at Boston University

Boston University

Boston University is a private research university located in Boston, Massachusetts. With more than 4,000 faculty members and more than 31,000 students, Boston University is one of the largest private universities in the United States and one of Boston's largest employers...

, Bell was engaged in training teachers in the art of instructing deaf mutes how to speak, and experimented with the Leon Scott phonautograph

Phonautograph

The phonautograph is the earliest known device for recording sound. Previously, tracings had been obtained of the sound-producing vibratory motions of tuning forks and other objects by physical contact with them, but not of actual sound waves as they propagated through air or other media. Invented...

in recording the vibrations of speech. This apparatus consists essentially of a thin membrane vibrated by the voice and carrying a light-weight stylus, which traces an undulatory line on a plate of smoked glass

Smoked glass

The term smoked glass refers to two different types of glass. It can be either of the following: Smoked glass is a flat sheet of glass held in the smoke of a candle flame such that one surface of the sheet of glass is covered in a layer of smoke residue...

. The line is a graphic representation of the vibrations of the membrane and the waves of sound in the air.

This background prepared Bell for work with spoken sound waves and electricity. He began his experiments in 1873-1874 with a harmonic telegraph, following the examples of Bourseul, Reis, and Gray. Bell's designs employed various on-off-on-off make-break current-interrupters driven by vibrating steel reeds which sent interrupted current to a distant receiver electro-magnet that caused a second steel reed or tuning fork to vibrate.

During a June 2, 1875 experiment by Bell and his assistant Thomas Watson

Thomas A. Watson

Thomas Augustus Watson was an assistant to Alexander Graham Bell, notably in the invention of the telephone in 1876. He is best known because his name was one of the first words spoken over the telephone. "Mr. Watson - Come here - I want to see you." were the first words Bell said using the new...

, a receiver reed failed to respond to the intermittent current supplied by an electric battery. Bell told Watson, who was at the other end of the line, to pluck the reed, thinking it had stuck to the pole of the magnet. Mr. Watson complied, and to his astonishment Bell heard a reed at his end of the line vibrate and emit the same timbre of a plucked reed, although there was no interrupted on-off-on-off current from a transmitter to make it vibrate. A few more experiments soon showed that his receiver reed had been set in vibration by the magneto-electric currents induced in the line by the motion of the distant receiver reed in the neighborhood of its magnet. The battery current was not causing the vibration but was needed only to supply the magnetic field in which the reeds vibrated. Moreover, when Bell heard the rich overtones of the plucked reed, it occurred to him that since the circuit was never broken, all the complex vibrations of speech might be converted into undulating (alternating) currents, which in turn would reproduce the complex timbre, amplitude, and frequencies of speech at a distance.

After Bell and Watson discovered on June 2, 1875 that movements of the reed alone in a magnetic field could reproduce the frequencies and timbre of spoken sound waves, Bell reasoned by analogy with the mechanical phonautograph that a skin diaphragm would reproduce sounds like the human ear when connected to a steel or iron reed or hinged armature. On July 1, 1875, he instructed Watson to build a receiver consisting of a stretched diaphragm or drum of goldbeater's skin

Goldbeater's skin

Goldbeater's skin — the outer membrane of calf's intestine — is a parchment traditionally used in the process of making gold leaf by beating, reducing gold into mere 1μm-thick leaves....

with an armature of magnetized iron attached to its middle, and free to vibrate in front of the pole of an electromagnet in circuit with the line. A second membrane-device was built for use as a transmitter. This was the "gallows" phone. A few days later they were tried together, one at each end of the line, which ran from a room in the inventor's house in Boston to the cellar underneath. Bell, in the work room, held one instrument in his hands, while Watson in the cellar listened at the other. Bell spoke into his instrument, “Do you understand what I say?” and Mr. Watson answered “Yes”. However, the voice sounds were not distinct and the armature tended to stick to the electromagnet pole and tear the membrane.

Because of illness and other commitments, Bell made little or no telephone improvements or experiments for eight months until after his U.S. patent 174,465 was published.

Bell's success

The first successful bi-directional transmission of clear speech by Bell and Watson was made on March 10, 1876 when Bell spoke into the device, “Mr. Watson, come here, I want to see you.” and Watson answered. Bell tested Gray's liquid transmitter design in this experiment, but only after Bell's patent was granted and only as a proof of concept

Proof of concept

A proof of concept or a proof of principle is a realization of a certain method or idea to demonstrate its feasibility, or a demonstration in principle, whose purpose is to verify that some concept or theory that has the potential of being used...

scientific experiment to prove to his own satisfaction that intelligible "articulate speech" (Bell's words) could be electrically transmitted. Because a liquid transmitter was not practical for commercial products, Bell focused on improving the electromagnetic telephone after March 1876 and never used Gray's liquid transmitter in public demonstrations or commercial use.

Bell's telephone transmitter (microphone) consisted of a double electromagnet, in front of which a membrane, stretched on a ring, carried an oblong piece of soft iron cemented to its middle. A funnel-shaped mouthpiece directed the voice sounds upon the membrane, and as it vibrated, the soft iron “armature” induced corresponding currents in the coils of the electromagnet. These currents, after traversing the wire, passed through the receiver which consisted of an electromagnet in a tubular metal can having one end partially closed by a thin circular disc of soft iron. When the undulatory current passed through the coil of this electromagnet, the disc vibrated, thereby creating sound waves in the air.

This primitive telephone was rapidly improved. The double electromagnet was replaced by a single permanently magnetized bar magnet

Magnet

A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...

having a small coil or bobbin of fine wire surrounding one pole, in front of which a thin disc of iron was fixed in a circular mouthpiece. The disc served as a combined diaphragm and armature. On speaking into the mouthpiece, the iron diaphragm vibrated with the voice in the magnetic field

Magnetic field

A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...

of the bar-magnet pole, and thereby caused undulatory currents in the coil. These currents, after traveling through the wire to the distant receiver, were received in an identical apparatus. This design was patented by Bell on January 30, 1877. The sounds were weak and could only be heard when the ear was close to the earphone/mouthpiece, but they were distinct.

The first long distance telephone call was made on 10 August 1876 by Bell from the family homestead in Brantford

Brantford, Ontario

Brantford is a city located on the Grand River in Southern Ontario, Canada. While geographically surrounded by the County of Brant, the city is politically independent...

, Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, to his assistant located in Paris

Paris, Ontario

Paris, Ontario is a community on the Grand River in Ontario, Canada. The town was established in 1850. In 1999, its town government was amalgamated into that of the County of Brant, Ontario, thus ending about 149 years as a separate incorporated municipality.-History:The town was first settled in...

, Ontario

Ontario

, some 10 miles (16 km) apart.

Earliest public demonstration of Bell's telephone

In June 1876, Bell exhibited a telephone prototype at the Centennial Exhibition in Philadelphia, where it attracted the attention of Brazilian emperor Pedro II

Pedro II of Brazil

Dom Pedro II , nicknamed "the Magnanimous", was the second and last ruler of the Empire of Brazil, reigning for over 58 years. Born in Rio de Janeiro, he was the seventh child of Emperor Dom Pedro I of Brazil and Empress Dona Maria Leopoldina and thus a member of the Brazilian branch of...

and physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

and engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

Sir William Thomson

William Thomson, 1st Baron Kelvin

William Thomson, 1st Baron Kelvin OM, GCVO, PC, PRS, PRSE, was a mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging...

, the 1st Baron Kelvin (best known as "Lord Kelvin"). In August 1876 at a meeting of the British Association for the Advancement of Science, Thomson revealed the telephone to the European public. In describing his visit to the Philadelphia Exhibition, Thomson said, 'I heard [through the telephone] passages taken at random from the New York newspapers: "s.s. Cox has arrived" (I failed to make out the s.s. Cox); "The City of New York", "Senator Morton", "The Senate has resolved to print a thousand extra copies", "The Americans in London have resolved to celebrate the coming Fourth of July!" All this my own ears heard spoken to me with unmistakable distinctness by the then circular disc armature of just such another little electro-magnet as this I hold in my hand.'

Later public demonstrations

The later telephone design was publicly exhibited on May 4, 1877 at a lecture given by Professor Bell in the Boston Music Hall

Boston Music Hall

The Boston Music Hall was a concert hall located on Winter Street in Boston, Massachusetts, with an additional entrance on Hamilton Place.One of oldest continuously operating theaters in the United States, it was built in 1852 and was the original home of the Boston Symphony Orchestra. The hall...

. According to a report: Going to the small telephone box with its slender wire attachments, Mr. Bell coolly asked, as though addressing some one in an adjoining room, “Mr. Watson, are you ready!” Mr. Watson, five miles away in Somerville, promptly answered in the affirmative, and soon was heard a voice singing “America”. [...] Going to another instrument, connected by wire with Providence, forty-three miles distant, Mr. Bell listened a moment, and said, “Signor Brignolli, who is assisting at a concert in Providence Music Hall, will now sing for us.” In a moment the cadence of the tenor's voice rose and fell, the sound being faint, sometimes lost, and then again audible. Later, a cornet solo played in Somerville was very distinctly heard. Still later, a three-part song came over the wire from Somerville, and Mr. Bell told his audience “I will switch off the song from one part of the room to another, so that all can hear.” At a subsequent lecture in Salem, Massachusetts

Salem, Massachusetts

Salem is a city in Essex County, Massachusetts, United States. The population was 40,407 at the 2000 census. It and Lawrence are the county seats of Essex County...

, communication was established with Boston, eighteen miles distant, and Mr. Watson at the latter place sang “Auld Lang Syne

Auld Lang Syne

"Auld Lang Syne" is a Scots poem written by Robert Burns in 1788 and set to the tune of a traditional folk song . It is well known in many countries, especially in the English-speaking world; its traditional use being to celebrate the start of the New Year at the stroke of midnight...

”, “The Star-Spangled Banner

The Star-Spangled Banner

"The Star-Spangled Banner" is the national anthem of the United States of America. The lyrics come from "Defence of Fort McHenry", a poem written in 1814 by the 35-year-old lawyer and amateur poet, Francis Scott Key, after witnessing the bombardment of Fort McHenry by the British Royal Navy ships...

”, and “Hail Columbia

Hail, Columbia

"Hail, Columbia" is an American patriotic song. It was considered, with several other songs, one of the unofficial national anthems of the United States until 1931, when "The Star-Spangled Banner" was officially named the national anthem...

”, while the audience at Salem joined in the chorus.

Summary of Bell's achievements

Bell did for the telephone what Henry Ford

Henry Ford

Henry Ford was an American industrialist, the founder of the Ford Motor Company, and sponsor of the development of the assembly line technique of mass production. His introduction of the Model T automobile revolutionized transportation and American industry...

did for the automobile. Although not the first to experiment with telephonic devices, Bell and the companies founded in his name were the first to develop commercially practical telephones around which a successful business could be built and grow. Bell adopted carbon transmitters similar to Edison's transmitters and adapted telephone exchanges and switching plug boards developed for telegraphy. Watson and other Bell engineers invented numerous other improvements to telephony. Bell succeeded where others failed to assemble a commercially viable telephone system. It can be argued that Bell invented the telephone industry. Bell's first transmission of voice of electric wire was named an IEEE Milestone.

Water microphone - Elisha Gray

Elisha Gray

Elisha Gray was an American electrical engineer who co-founded the Western Electric Manufacturing Company...

recognized the lack of fidelity of the make-break transmitter of Reis and Bourseul and reasoned by analogy with the lover's telegraph

Tin can telephone

A tin can telephone is a type of voice-transmitting device made up of two tin cans, paper cups or similarly shaped items attached to either end of a taut string or wire.- How it works :...

, that if the current could be made to more closely model the movements of the diaphragm, rather than simply opening and closing the circuit, greater fidelity might be achieved. Gray filed a patent caveat

Patent caveat

with the US patent office on February 14, 1876 for a liquid microphone

Water microphone

. The device used a metal needle or rod that was placed — just barely — into a liquid conductor, such as a water/acid mixture. In response to the diaphragm's vibrations, the needle dipped more or less into the liquid, varying the electrical resistance and thus the current passing through the device and on to the receiver. Gray did not convert his caveat into a patent application until after the caveat had expired and hence left the field open to Bell.

When Gray applied for a patent for the variable resistance telephone transmitter, the Patent Office determined "while Gray was undoubtedly the first to conceive of and disclose the variable resistance

Electrical resistance

The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...

invention, as in his caveat of 14 February 1876, his failure to take any action amounting to completion until others had demonstrated the utility of the invention deprives him of the right to have it considered."

Carbon microphone - Thomas Edison

Thomas Alva Edison took the next step in improving the telephone with his invention in 1878 of the carbon grain "transmitter"

Carbon microphone

The carbon microphone, also known as a carbon button microphone or a carbon transmitter, is a sound-to-electrical signal transducer consisting of two metal plates separated by granules of carbon. One plate faces outward and acts as a diaphragm...

(microphone) that provided a strong voice signal on the transmitting circuit that made long-distance calls practical. Edison discovered that carbon grains, squeezed between two metal plates, had a variable electrical resistance

Electrical resistance

that was related to the pressure. Thus, the grains could vary their resistance as the plates moved in response to sound waves, and reproduce sound with good fidelity, without the weak signals associated with electro-magnetic transmitters.

The carbon microphone was further improved by Emile Berliner

Emile Berliner

Emile Berliner or Emil Berliner was a German-born American inventor. He is best known for developing the disc record gramophone...

, Francis Blake

Francis Blake (telephone)

Francis Blake, Jr. was born in Needham, Massachusetts, the son of Caroline Burling and Francis Blake, Sr. and died in Weston, Massachusetts....

, David E. Hughes

David E. Hughes

David Edward Hughes , was a British scientist and musician. Hughes was co-inventor of the microphone, a harpist and a professor of music.-Biography:...

, Henry Hunnings

Henry Hunnings

Henry Hunnings was a British clergyman and inventor from Bothwell, Yorkshire. Hunnings received a patent on September 16, 1878 for a new type of carbon microphone for use with telephones....

, and Anthony White

Anthony C. White

Anthony C. White was an electrical engineer who improved the carbon microphone for use with telephones manufactured by the American Bell Telephone company....

. The carbon microphone remained standard in telephony until the 1980s, and is still being produced.

Improvements to the early telephone

Additional inventions such as the call bell

Ringing (telephony)

A ringing signal operates a bell or other ringtone generator in a telephone, to alert the user to an incoming telephone call.Telephone bells or ringtones are rung by impressing a 105-volt RMS 20-Hertz sine wave across the tip and ring conductors of the subscriber line. This signal is produced by a...

, central telephone exchange

Telephone exchange

In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...

, common battery

Common battery

In telecommunication, a Common battery is a single electrical power source used to energize more than one circuit, electronic component, equipment, or system....

, ring tone, amplification

Amplifier

Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...

, trunk lines

Trunking

In modern communications, trunking is a concept by which a communications system can provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually. This is analogous to the structure of a tree with one trunk and many branches. Examples of...

, wireless phones, etc. were made by various engineers who made the telephone the useful and widespread apparatus it is now.

Telephone exchange - Tivadar Puskás

Tivadar Puskás

Tivadar Puskás was a Hungarian inventor, telephone pioneer, and inventor of the telephone exchange He was also the founder of Telefon Hírmondó.-Biography:...

was working on his idea for a telegraph exchange when Alexander Graham Bell

Alexander Graham Bell

Alexander Graham Bell was an eminent scientist, inventor, engineer and innovator who is credited with inventing the first practical telephone....

received the first patent for the telephone

Telephone

. This caused Puskás to take a fresh look at his own work and he refocused on perfecting a design for a telephone exchange

Telephone exchange

In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...

. Puskás got in touch with the American inventor Thomas Edison

Thomas Edison

Thomas Alva Edison was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and a long-lasting, practical electric light bulb. In addition, he created the world’s first industrial...

who liked the design. According to Edison, "Tivadar Puskas was the first person to suggest the idea of a telephone exchange". Puskás's idea finally became a reality in 1877 in Boston.
It was then that the Hungarian word "hallom" "I hear you" was used for the first time in a telephone conversation when, on hearing the voice of the person at the other end of the line, Puskás shouted "hallom". This cannot be confirmed by any original documents, however it has passed into Hungarian modern folklore. Hallom was shortened to Hello

Hello

Hello is a salutation or greeting in the English language. It is attested in writing as early as the 1830s.-First use:Hello, with that spelling, was used in publications as early as 1833. These include an 1833 American book called The Sketches and Eccentricities of Col...

, an older greeting that can be traced back to the Old English verb hǽlan.

Controversy

Bell has been widely recognized as the "inventor" of the telephone outside of Italy, where Meucci was championed as its inventor. In the United States, there are numerous reflections of Bell as a North American icon for inventing the telephone, and the matter was for a long time non-controversial. In June 2002, however, the United States House of Representatives

United States House of Representatives

passed a symbolic bill recognizing the contributions of Antonio Meucci "in the invention of the telephone" (not "for the invention of the telephone"), throwing the matter into some controversy. Ten days later the Canadian parliament

Parliament of Canada

The Parliament of Canada is the federal legislative branch of Canada, seated at Parliament Hill in the national capital, Ottawa. Formally, the body consists of the Canadian monarch—represented by her governor general—the Senate, and the House of Commons, each element having its own officers and...

countered with a symbolic motion conferring official recognition for the invention of the telephone to Bell.

Champions of Meucci, Manzetti, and Gray have each offered fairly precise tales of a contrivance whereby Bell actively stole the invention of the telephone from their specific inventor. In the 2002 congressional resolution, it was inaccurately noted that Bell worked in a laboratory in which Meucci's materials had been stored, and claimed that Bell must thus have had access to those materials. Manzetti claimed that Bell visited him and examined his device in 1865. And it is alleged that Bell bribed a patent examiner, Zenas Wilber, not only into processing his application before Gray's, but allowing a look at his rival's designs before final submission.

One of the valuable claims in Bell's 1876 was claim 4, a method of producing variable electrical current in a circuit by varying the resistance in the circuit. That feature was not shown in any of Bell's patent drawing

Patent drawing

A patent application or patent may contain drawings, also called patent drawings, illustrating the invention, some of its embodiments , or the prior art...

s, but was shown in Elisha Gray's drawings in his caveat

Patent caveat

filed the same day, 14 February 1876. A description of the variable resistance feature, consisting of seven sentences, was inserted into Bell's application. That it was inserted is not disputed. But when it was inserted is a controversial issue. Bell testified that he wrote the sentences containing the variable resistance feature before 18 January 1876 "almost at the last moment" before sending his draft application to his lawyers. A book by Evenson argues that the seven sentences and claim 4 were inserted, without Bell's knowledge, just before Bell's application was hand carried to the Patent Office by one of Bell's lawyers on 14 February 1876.

Contrary to the popular story, Gray's caveat was taken to the US Patent Office a few hours before Bell's application. Gray's caveat was taken to the Patent Office in the morning of 14 February 1876 shortly after the Patent Office opened and remained near the bottom of the in-basket until that afternoon. Bell's application was filed shortly before noon on 14 February by Bell's lawyer who requested that the filing fee be entered immediately onto the cash receipts blotter and Bell's application was taken to the Examiner immediately. Late in the afternoon, Gray's caveat was entered on the cash blotter and was not taken to the Examiner until the following day. The fact that Bell's filing fee was recorded earlier than Gray's led to the myth that Bell had arrived at the Patent Office earlier. Bell was in Boston on 14 February and did not know this happened until later. Gray later abandoned his caveat and did not contest Bell's priority. That opened the door to Bell being granted US patent 174465 for the telephone on 7 March 1876.

External links

Alexander Bell's Experiments - the tuning fork and liquid transmitter.
American Treasures of the Library of Congress, Alexander Graham Bell - Lab notebook I, pages 40-41 (image 22)
Scientific American Supplement No. 520, December 19, 1885
Telephone Patents

Patents

US 250126 Speaking Telephone by Francis Blake (November 29, 1881)
US 474230 Speaking Telegraph (graphite transmitter) by Thomas Edison (Western Union) May 3, 1892
US 485311 Telephone (solid back carbon transmitter) by Anthony C. White (Bell engineer) November 1, 1892
US 687499 Telephone Transmitter (carbon granules "candlestick" microphone) by W.W. Dean (Kellogg Co.) November 26, 1901
US 815176 Automatic Telephone Connector Switch (for rotary dial phones) by A E Keith and C J Erickson March 13, 1906

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Charles Grafton Page

Innocenzo Manzetti

Charles Bourseul

Johann Philipp Reis

Antonio Meucci

Chronology of Meucci's invention

Cromwell Varley

Poul la Cour

Daniel Drawbaugh

Elisha Gray

Alexander Graham Bell

Bell's success

Earliest public demonstration of Bell's telephone

Later public demonstrations

Summary of Bell's achievements

Water microphone - Elisha Gray

Carbon microphone - Thomas Edison

Improvements to the early telephone

Telephone exchange - Tivadar Puskás

Controversy

See also

Further reading

External links

Patents