By 1874, Bell's initial work on the harmonic telegraph had entered a formative stage, with progress made both at his new Boston "laboratory" (a rented facility) and 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 would correspond to sound waves. He also believed that he would be able to convert the undulating currents back into sound by tuning multiple metal reeds to different frequencies. 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 began to financially support Bell's experiments. Patent matters were handled by Hubbard's
patent attorney,
Anthony Pollok. In March 1875, Bell and Pollok visited the scientist
Joseph Henry, then the director of the
Smithsonian Institution, to ask his advice on the electrical multi-reed apparatus that Bell hoped would transmit the human voice by telegraph. Henry said Bell had "the germ of a great invention". When Bell said that he lacked the necessary knowledge, Henry replied, "Get it!" That declaration greatly encouraged Bell to keep trying, even though he had neither the equipment needed to continue his experiments nor the ability to create a working model of his ideas. But 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 that. With financial support from Sanders and Hubbard, Bell hired Watson as his assistant, and the two 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 reed's 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.
The race to the patent office In 1875, Bell developed an
acoustic telegraph and drew up a
patent application for it. Since he had agreed to share U.S. profits with his investors, Gardiner Hubbard and Thomas Sanders, Bell requested that an associate in Ontario,
George Brown, attempt to patent it in Britain, instructing his lawyers to apply for a patent in the U.S. only after they received word from Britain (Britain issued patents only for discoveries not previously patented elsewhere). Meanwhile,
Elisha Gray was also experimenting with acoustic telegraphy and thought of a way to transmit speech using a water transmitter. On February 14, 1876, Gray filed a
caveat with the U.S. Patent Office for a telephone design that used a water transmitter. That same morning, Bell's lawyer filed Bell's application with the patent office. There is considerable debate about who arrived first and Gray later challenged the primacy of Bell's patent. Bell was in Boston on February 14 and did not arrive in Washington until February 26. On March 7, 1876, the
U.S. Patent Office issued Bell patent 174,465. It covered "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" Bell returned to Boston that day and the next day resumed work, drawing in his notebook a diagram similar to that in Gray's patent caveat. On March 10, Bell succeeded in getting his telephone to work, using a liquid transmitter similar to Gray's design. Vibration of the diaphragm caused a needle to vibrate in the water, varying the
electrical resistance in the circuit. When Bell spoke the sentence "Mr. Watson—Come here—I want to see you" into the liquid transmitter, Watson, listening at the receiving end in an adjoining room, heard the words clearly. Although Bell was, and still is, accused of stealing the telephone from Gray, Bell used Gray's water transmitter design only after Bell's patent had been granted, and only as a
proof of concept scientific experiment, to prove to his own satisfaction that intelligible "articulate speech" (Bell's words) could be electrically transmitted. After March 1876, Bell focused on improving the electromagnetic telephone and never used Gray's liquid transmitter in public demonstrations or commercial use. The examiner raised the question of priority for the variable resistance feature of the telephone before approving Bell's patent application. He told Bell that his claim for the variable resistance feature was also described in Gray's caveat. Bell pointed to a variable resistance device in his previous application in which he described a cup of mercury, not water. He had filed the mercury application at the patent office on February 25, 1875, long before Gray described the water device. In addition, Gray abandoned his caveat, and because he did not contest Bell's priority, the examiner approved Bell's patent on March 3, 1876. Gray had reinvented the variable resistance telephone, but Bell was the first to write down the idea and test it in a telephone. The
patent examiner, Zenas Fisk Wilber, later stated in an
affidavit that he was an alcoholic who was much in debt to Bell's lawyer,
Marcellus Bailey, with whom he had served in the Civil War. He said he had shown Bailey Gray's patent caveat. Wilber also said (after Bell arrived in Washington D.C. from Boston) that he showed Bell Gray's caveat and that Bell paid him $100 (). Bell said they discussed the patent only in general terms, although in a letter to Gray, Bell admitted that he learned some of the technical details. Bell denied in an affidavit that he ever gave Wilber any money.
Later developments On March 10, 1876, Bell used "the instrument" in Boston to call Thomas Watson who was in another room but out of earshot. He said, "Mr. Watson, come here – I want to see you" and Watson soon appeared at his side. Continuing his experiments in Brantford, Bell brought home a working model of his telephone. On August 3, 1876, from the telegraph office in Brantford, Bell sent a telegram to the village of Mount Pleasant away, indicating that he was ready. He made a telephone call via telegraph wires and faint voices were heard replying. The following night, he amazed guests as well as his family with a call between the Bell Homestead and the office of the Dominion Telegraph Company in Brantford along an improvised wire strung up along telegraph lines and fences, and laid through a tunnel. This time, guests at the household distinctly heard people in Brantford reading and singing. The third test, on August 10, 1876, was made via the telegraph line between Brantford and Paris, Ontario, away. This test is said by many sources to be the "world's first long-distance call". It proved that the telephone could work over long distances, at least as a one-way call. The first two-way (reciprocal) conversation over a line occurred between Cambridge and Boston (roughly 2.5 miles) on October 9, 1876. During that conversation, Bell was on Kilby Street in Boston and Watson was at the offices of the Walworth Manufacturing Company. Bell and his partners, Hubbard and Sanders, offered to sell the patent outright to Western Union for $100,000, equal to $ today, but it did not work (according to an apocryphal story, the president of Western Union balked, countering that the telephone was nothing but a toy). Two years later, he told colleagues that if he could get the patent for $25 million (equal to $ today), he would consider it a bargain. By then, the Bell company no longer wanted to sell the patent. Bell's investors became millionaires while he fared well from residuals and at one point had assets of nearly $1 million. Bell began a series of public demonstrations and lectures to introduce the new invention to the
scientific community as well as the general public. A short time later,
his demonstration of an early telephone prototype at the 1876
Centennial Exposition in
Philadelphia brought the telephone to international attention. Influential visitors to the exhibition included Emperor
Pedro II of Brazil. One of the judges at the Exhibition,
Sir William Thomson (later Lord Kelvin), a renowned Scottish scientist, described the telephone as "the greatest by far of all the marvels of the electric telegraph". On January 14, 1878, at
Osborne House, on the
Isle of Wight, Bell demonstrated the device to
Queen Victoria, placing calls to Cowes, Southampton, and London. These were the first publicly witnessed long-distance telephone calls in the
UK. The queen found the process "quite extraordinary" although the sound was "rather faint". She later asked to buy the equipment that was used, but Bell offered to make "a set of telephones" specifically for her. The
Bell Telephone Company was created in 1877, and by 1886, more than 150,000 people in the U.S. owned telephones. Bell Company engineers made numerous other improvements to the telephone, which emerged as one of the most successful products ever. In 1879, the company acquired Edison's patents for the
carbon microphone from Western Union. This made the telephone practical for longer distances, and it was no longer necessary to shout to be heard at the receiving telephone. Pedro II of Brazil was the first person to buy stock in the Bell Telephone Company. One of the first telephones in a private residence was installed in his palace in
Petrópolis, his summer retreat from
Rio de Janeiro. In January 1915, Bell made the first ceremonial transcontinental
telephone call. Calling from the AT&T head office at 15 Dey Street in New York City, Bell was heard by
Thomas Watson at 333 Grant Avenue in San Francisco.
The New York Times reported:
Competitors As is sometimes common in scientific discoveries, simultaneous developments occurred, as evidenced by a number of inventors who were at work on the telephone. Over 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 Bell's original 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. 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 the trial had wound its way through nine years of legal battles, the U.S. prosecuting attorney had died and the two Bell patents (No. 174,465, 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
U.S. 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 hope of establishing his invention's priority. Meucci's testimony was disputed due to 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 incorporated as a subsidiary of Western Union in 1901. Meucci's work, like that of 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. But due to the efforts of Congressman
Vito Fossella, on June 11, 2002, the
U.S. House of Representatives stated that Meucci's "work in the invention of the telephone should be acknowledged". This did not put an end to the still contentious issue. Some modern scholars do not agree that Bell's work on the telephone was influenced by Meucci's inventions. The value of Bell's patent was acknowledged throughout the world, and patent applications were made in most major countries. When Bell delayed the German patent application, the electrical firm
Siemens & Halske set up a rival manufacturer of Bell telephones under its own patent. Siemens 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.{{multiref2|| {{Cite journal|date=June 1910 ==Family life==