How the biggest patent dispute of all time contributed to the development of the telephone

Prof. Dr.-Ing. Dieter Brückmann on Alexander Graham Bell and the success story of the telephone

Alexander Graham Bell, a native of Scotland, known in America as an audiologist, inventor, major entrepreneur and eugenicist, died on August 2, 1922. What was his outstanding achievement?

Brückmann: Alexander Graham Bell is always associated in the first place with the invention of the telephone, even though he was active in many different fields. Building on the ideas of other inventors, he developed the telephone to market maturity and applied for a patent for it in 1876, just hours before his biggest competitor, Elisha Gray. Despite years of litigation, Bell was awarded this patent, probably one of the most valuable patents ever granted. To market his invention, the Bell Telephone Company was founded by a group around Gardiner Hubbard with the participation of Alexander Graham Bell. Bell took on the role of technical advisor in this company. Although he largely withdrew from this company as early as 1880, it later developed into one of the world's most successful telephone companies.

Phonetic communication played a special role in the Bell family. Do you know why?

Brückmann: Both Alexander Graham Bell's grandfather and father were already involved in spoken communication, the latter even developing a universal phonetic phonetic transcription as part of his professorship in speech and elocution. Alexander Graham Bell's mother suffered from a hearing impairment and was almost deaf. Bell therefore employed special speech techniques that made it possible for him to converse with her nonetheless. She was also able to perceive his piano playing through the acoustic vibrations. Through this early awareness of spoken language communication, Alexander Graham Bell became a proponent of spoken language oriented methods of education for the deaf, as an alternative to signed language oriented methods. Even after moving to North America, he worked for several years in Northhampton, Massachusetts, as a teacher of the deaf and at Boston University as a professor of speech technology and physiology. He also met the deaf Mabel Hubbard, the daughter of one of his later supporters and business partners, through his work as a teacher of the deaf. In 1877, Mabel and he married.

Bell studied Latin and Greek and at 17 became a teacher of speech and music in Scotland. Even then he began his first research in acoustics and met the German polymath Hermann von Helmholtz, who influenced him greatly. In what?

Brückmann: Helmholtz, a German physicist and physiologist, had already published the work "Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik" in 1863. The approaches described in it had a great effect on the young Bell and strongly influenced him in his further work.

Bell studied anatomy and physiology in London. After two of his brothers died of tuberculosis, the family moved to Canada because of the better climate, where Bell later became a professor of speech technology and physiology of the voice at Boston University. In 1874, he conducted acoustic experiments to record sound waves and constructed a so-called phon automaton, a device that recorded the vibrations of sound on a sooted cylinder. Why were these experiments important?

Brückmann: In Alexander Graham Bell's phon automaton, sound was picked up by an ear and recorded on a sooted metal cylinder for optical viewing. The ear had previously been removed from a corpse. This was to make the composition of the sound optically recognizable, which in turn was to enable the deaf to better control speech. Sound reproduction was not yet considered. Even though the experiments were not very successful at first, they made an important contribution to the construction of a functioning telephone. Here, too, sound had to be implemented in a similar way.

In 1876, he achieved the most lasting historical success to date. In doing so, he drew on the preliminary work of the Italian Antonio Meucci, who was only thanked posthumously for his achievements in 2002. What is this about?

Brückmann: The Italian scientist and inventor Antonio Meucci had already discovered in the 1830s that sound can be transmitted by electrical oscillations in copper wire. In 1850, he moved to the USA where he further developed his telephone. He applied for a patent for his so-called "Telettrofono" as early as 1871, but this was not granted for over two years, so the application lapsed. Meucci submitted his papers and equipment to Edward B. Grant, vice president of the American District Telegraph Co. to have his invention tested on their telegraph cable, but was stalled for more than two years. In the meantime, Bell, now working in Meucci's former workshops at the American District Telegraph Co. used its materials and records to further develop his own telephone. In 1876, Bell finally became the first to apply for a patent for this. Despite decades of disputes with Bell, Meucci did not succeed in obtaining the patent or at least financial compensation. He died an impoverished man.

Bell also profited from the basic research of the German Philipp Reis, who had already developed a sound-transmitting device that he called "Telephon". Can one say that Bell made use of other, non-proprietary scientific findings?

Brückmann: You could say that the time was ripe for the telephone when Bell filed his patent in 1876. Important basic research in the field of spoken communication was done by Philip Reis, but also by others. Philip Reis developed his "telephone" already in the period from 1858 to 1863 and sold it in larger numbers as a demonstration object. Through this, it also reached foreign countries. This device in turn inspired a number of inventors to experiment and further develop it. Bell also came into contact with it both in Edinburgh and later in the USA. It is undisputed that he certainly benefited greatly from the basic research of Philip Reis, which was very important to him. Even though Bell was greatly inspired by the preliminary work of others, he also contributed his own important improvements. Finally, he had good contacts with people who promoted his work, so that he was the first to successfully apply for a patent for acoustic sound transmission.

Bell filed his patent for a telephone just two hours before another application by Elisha Gray, and a fractious patent battle ensued, with Gray's model actually working. Nevertheless, Bell prevailed. Was it all above board at the time?

Brückmann: Both Bell and Gray were working on the so-called "harmonic telegraph" before they filed their patent applications. This was intended to transmit different tones over a telegraph line. Presumably, both of them independently further developed the knowledge they had gained and incorporated it into their patent applications. The dispute between the two over the priority of their inventions was, however, a constant from the very beginning. In contrast to Gray, Bell did not have a working device, but he had already gained experience in preparing patent applications. In his application, he described the principle for the transmission of sounds in a form that was completely sufficient at that time to be recognized as a patent. The application was filed on February 14, 1876, through his attorney Gardiner Greene Hubbard. Only two hours later, but still later, Elisha Gray filed his application, whereby he could also refer to a functioning device. The application filed by Bell through Hubbard led to the largest patent dispute ever. After the patent was issued on March 7, 1876, some suspected an illegal connection between Bell and the patent office. Because the patent was broadly worded, there were nearly 600 oppositions to the patent over the years, but all were rejected. Bell's patent was unreservedly upheld in all the lawsuits. Even from today's point of view, it is not possible to say with certainty whether everything was in fact above board. In any case, Bell was very well connected and had financially strong friends in the background.

In 1881, the Bell telephone was finally ready for use, because he was now using electromagnetic induction. How do I have to imagine this?

Brückmann: If you move a coil, which is located around a fixed magnet, in one direction, an electromagnetic field is created. This generates a current in the coil in one direction. Moving the coil in the opposite direction creates a current flow in the opposite direction. This principle was discovered by the English physicist Faraday and is called electromagnetic induction. This principle can be used in a microphone by connecting the coil to a diaphragm. If the membrane is moved by the acoustic waves, this movement is transferred to the coil and a current is induced proportional to the movement. If this principle is reversed, a loudspeaker is created, so that acoustic signals can be generated again from the alternating currents. This principle was now also used by Bell in his telephones with further improvements.

Bell founded the Bell Telephone Company in 1877, but it was not successful at first. Why not?

Brückmann: To market his invention, the Bell Telephone Company was founded in July 1877 by a group around Gardiner Hubbard with the participation of Alexander Graham Bell and his assistant Watson. However, the company had great sales difficulties in the initial phase because the demand for telephones was not yet very great. Finally, the patents were offered to the big competitor, the Western Union Telegraph Company, where Elisha Gray was also employed. However, the latter refused, which in retrospect turned out to be a big mistake. After several mergers of the Bell Telephone Company with other companies, the "American Telephone and Telegraph Company" (AT&T) was founded as a subsidiary in 1885. This company later became one of the world's most successful telephone companies.

After several transfer activities, the success story of the telephone began, which today is marketed by the American Telephone and Telegraph Company, or AT&T for short. When Bell died in 1922, all telephone traffic in the United States rested for one minute. What does science think about him today?

Brückmann: While in American and Anglo-Saxon literature Bell is usually named first as the inventor of the telephone, in German-language literature this is very often Philip Reis. In Italy and some other countries, the merits of Meucci are also emphasized in particular, and he was even subsequently recognized as the inventor of the telephone by a resolution of the U.S. House of Representatives on June 11. In any case, it is undisputed worldwide that Bell succeeded, based on his patent application and the support of wealthy friends, in designing a functional telephone that could also be produced in large quantities. This represented the breakthrough for telephony, which subsequently spread all over the world with exponential growth. Bell's success can certainly be attributed to several factors. These include, in particular, his intuition, his extensive knowledge in the field of sound technology, his broad scientific and technical understanding, his good networking, including with financial backers, and ultimately also the luck of having done the right thing at the right time. In the later course of his life Bell received numerous honors, even the unit for the level Bel or decibel is named after him. This clearly shows the esteem in which he is held worldwide.

Uwe Blass (conversation of 24.05.2022)

Prof. Dr.-Ing Dieter Brückmann is head of the Department of Communications Engineering, Components and Circuit Technology in the Faculty of Electrical Engineering, Media Technology and Information Technology at Bergische Universität.