Philipp Reis
Antonio Meucci
Elisha Gray
Alexander Graham Bell
Bell Telephone Company
The Telephone Network
Hello
Almond Strowger

History of Telephony

The idea of ​​the Telephone

Telegraphy was the established technology for telecommunications in the mid-19th century. However, it wasn’t very efficient. Like a letter, information first had to be written down, then it was transmitted and had to be converted back into words by the recipient.

• Information is converted into words
• Words are converted into letters
• Letters are converted to (Morse) code
• Morse code is converted into electrical pulses
• The pulses are transmitted
• The pulses are received and recorded in codes
• The codes are converted into letters
• Letters is converted into words
• Words are converted into information

It would be a tremendous advantage if spoken language could be directly transmitted electrically.

• Information is converted into (acoustic) speech
• Speech is converted into an electrical signal
• The signals are transmitted
• The signals are converted into speech
• Speech is converted into information

Aside from the higher efficiency, it is also possible save the staff that is required for the conversions. However, something revolutionary new has to happen. An acoustic wave (sound wave) must be converted into an „electrical wave“. Information passes from one physical medium (acoustic/mechanical) to another physical medium (electromagnetic) and vice versa. The magic „converters“ are called microphones and loudspeakers. Naturally, they were developed together as „The Telephone“.

Philipp Reis

One of the first engineers to convert sound into electrical waves was Philipp Reis. He was not a renowned scientist like Gauss and Weber, but a simple teacher. His model for a microphone was initially the human ear. For demonstrations to his students, he built an ear-like funnel and placed a membrane at the end. Obviously a membrane, when it is thin enough, starts to vibrate, especially when it is placed at the and of a funnel. Now it was just necessary to pick up these vibrations electrically. For this purpose, Reis used a fine platinum foil in front of a metal plate. There was voltage between the foil and the plate and a current circuit was interrupted by the oscillations of the current and thus “modulated”. The receiving end consisted of a magnetized knitting needle placed in a coil through which the current from the „microphone“ passed. This caused the knitting needle to vibrate back and forth. These vibrations were amplified by a resonator.

In 1861, Reis was able to demonstrate his telephone and write a report about it. Unfortunately, the report did not get much attention. The renowned scientists even suppressed a publication in a specialist journal. From their point of view, the work had no scientific value. So it happened that the phone was not built in large numbers. From today’s perspective, the microphone is very rudimentary and it’s no wonder speech was barely intelligible when transmitted. But the principles were all correct to say that Philipp Reis was (one of) the inventors of the telephone. Unfortunately, Philip Reis did not live to see the successful breakthrough of the telephone.

„The horse doesn’t eat cucumber salad“ was the sentence Philipp Reis used in 1861 to demonstrate his telephone. It is believed to be the first publicly transmitted voice message using electricity.

Antonio Meussi

Another inventor of the telephone came from Italy. His name was Antonio Meucci. He was involved Italian war of indepedence in the 19th century and fled to America. Here he became an entrepreneur and produced stearin candles. Meucci had probably already built a telephone in 1856, which he described in his notes. His microphone consisted of a membrane attached to a coil. This in turn vibrated over a magnet which caused the current in the coil to be modulated by the sound waves. It was a significantly better microphone than the simple microphone of Philipp Reis.

However, Meucci was unable to build working prototypes of his phone. His candle factory went bankrupt and he himself became impoverished. Although he continues to work on his phone, he did not found any investors. In 1870 he finally found a financier but this investor just stepped back as Meucci was ready for a patent. So Meucci was unable to apply for a patent. Alexander Bell gained knowledge of the writings of Meucci and probably used them for his own developments. Meucci later sued Bell’s patent but without success.

Elisha Gray

There was a third inventor of the telephone: Elisha Gray. His invention primarily concerned the microphone. He also used a membrane to pick up the acoustic vibrations. He connected the membrane to a needle dipped in an acidic liquid. A current was passed through the needle and acid and thus modulated by the vibrations of the needle. In February 1876 Gray wanted to secure this telephone in the patent office. However, he was a few hours late and a certain Bell patented the phone before him.

Alexander Graham Bell

A fourth engineer was also working on a telephone. Alexander Graham Bell saw a telephone demonstrated by Philipp Reis in the 1960s. Since then he had the ambition to improve it and make a real product. Unlike Reis and Meucci, Bell was a mediocre inventor but a good and sometimes unscrupulous, businessman. He knew about Reis‘ and Meucci’s phones and built his own phone based on their findings. Bells phone did not have a good solution for a microphone. As a matter of fact, Bell didn’t even have a working phone when he filed a patent for it.

Curiously, he changed his patent specification around the microphone at exactly the same time as Gray was about to patent his telephone (February 1876). Now his phone suddenly had an acid microphone like the one from Elisha Grey. His attorneys managed to get the Bell patent into the patent office a few hours before Gray’s application. The Patent Office saw the similarity to Gray’s patent and asked Bell for an explanation. Bell brazenly claimed he had been working with liquid switches for years, and the patent office believed him. Not only did Bell get the patent, he also fought all other engineers who thought they invented the telephone. Mainly he sued Gray and Meucci.

Bell didn’t invent the telephone, but he marketed it in the best possible way.

Especially in America, Graham Bell is still portrayed, as the great inventor of the telephone. It wasn’t until 2002 that the United States Congress acknowledged that it was Meucci’s invention.

The Bell Telephone Company

Bell, aware of the value of the telephone, founded the Bell Telephone Company in 1877. This company, which later became the American Telephone and Telegraph Company (AT&T), is now one of the largest telecommunications companies in the world. The research department, Bell Laboratories, was the best research laboratory of the 20th century. Many of the discoveries discussed here came from this laboratory.

Bell’s company was not an immediate source of money. As a matter of fact it needed capital so badly that Bell wanted to sell the rights to the phone to Western Union for just $100,000. Western Union was the leading telegraph company in America at the time. The President of Western Union refused to buy the patent. „What’s a company like ours supposed to do with a toy like this,“ he sneered. He had the phone checked by his own engineers and got the feedback that the performance of this phone was poor and that this instrument could never cover more than a few miles. The push back of the phone was the most serious mistakes Western Union made. In the coming years Western Union lost more and more of its business to the Bell telephone company. In the end they were forced to focus just on the transfer of money, which they still do today.

The leading telecommunications company Western Union thought the phone was a gimmick with no future.

Bells was able to significantly improve his phone over time. The phone’s weak point, the microphone, was improved by using coal dust as a conductor. When a membrane presses on this coal dust, the resistance changes. This leads to well performing and solid converter, which was also easy to manufacture. Also this carbon microphone was not invented by Bell. In 1880 Bell had developed a telephone that could be produced in large numbers.

But not only Bell built telephones. In Germany, where Bell’s patent was not valid, Siemens, for example, began to improve and sell Bell telephones. In Sweden, Lars Magnus Ericsson worked with the telephone and founded a company in 1876 that is now one of the largest manufacturers of telecommunications equipment. Ericsson himself did not believe in the spread of the telephone. He thought it was a gimmick for rich businessmen.

In 1880 there were only 50,000 telephones in the world. Twenty years later there were already over two million.

The Telephone Network

The usage and popularity of telephones brought a new problem: switching. In the beginning, a telephone was just a voice connection between two devices, e.g. in different rooms, via an electrical line. This could be seen as a further development of telegraphy. Instead of transmitting a message in the form of a telegram, the message could now simply be spoken. You could even have a conversation if the connection was two-way. To do this, however, it would have been necessary for the participants to go to the telegraph stations and establish the connection there. Obviously it would be much more convenient to have the phone at home or at work and make a call from there. This required two things:

• A Call need to be initialized. „The other side“ need to be informed that there is an incoming call.
• A physical connection needed to be established.

The first problem was easy to solve. The „telephone bell“ was quickly invented and a crank was installed in the first telephones, which caused the telephone on the other side to ring.

To solve the second problem, it was required to route a telephone line to a control center: „The Office“. The office was also connected to many other telephones. A call was done via the office. First the Office was called and the „officer“ was informed which other participant should be connected. The Officer was then calling the other participant and finally established a direct connection by a „switch“.

A lot of terms we are using today in communication are still from this time

• To be connected (or to be disconnected)
• To be online (today you are online even though you don’t use a wire anymore)
• To ring somebody (eventhough no phone has a ring anymore today)
• Hang-Up, which was the the „hanging of the phone in the cradle“ which also disconnected the phone from the line.

The operators in the offices, later called switching centers where mostly female.

If somebody wanted to call people from another office, you had to establish a connection from office to office. Thus, there were local and long-distance calls. Long-distance calls were naturally more expensive because only one or a few lines were available for a potentially large number of participants. In addition, it was technically complex to conduct telephone calls over long distances, above all since there were no signal amplifiers for electrical signals in the early days.

Hello

There was another communication problem that came with the phone. You didn’t know exactly when and if a connection was made. When establishing a connection with the phone, the first thing the receiver had to do was to confirm that the connection was established and the sender could now start communicating. Bell and also the great industrialist and inventor Thomas Edison proposed a code word for this. Bell wanted „ahoy“, as used on ships at the beginning of a communication. Edison suggested the word „Hello“. Hello wasn’t very common before the usage of a phone, nobody used to say „Hello“ to somebody. The origin probably comes from the old Middle High German from „hol over“ the call for a ferryman.

The „hello“ prevailed. On the phone everybody started a call now with Hello. The ladies in the switching center were soon jokingly called „Hello Girls“.

Almond Strowger

Thanks to a funeral director named Almon Strowger, the female operators disappeared and were replaced by automatic switching systems. Allegedly, Strowger got fewer orders over the phone than its competitor. He saw the reason in the fact that the competitor’s sister worked in the telephone switching center. If someone asked for an undertaker, she would immediately put the customer through to her brother. So he looked for a system to replace the lady. In 1881 he invented a switching system in which a switch could move up and down vertically, creating 10 contacts and rotating at the same time, making 10 more connections. Thus 1 to 100 connections could be switched. If several such connections were connected in series, the number increased considerably. Two systems could select 10,000 endpoints. Controlling the lift and turn switch from the phone was pretty unreliable at first. You had to enter the impulses to move the switches yourself by hand. Therefore, in 1896, employees of his later company invented a “selection dial”. This had all the digits and had to be rotated. Turning 1 generated one pulse, turning 2 generated two pulses, etc. For decades this was the way dialing was done. In the end, the Strowger switching system also led to the telephone numbers that still exist today, even on mobile phones. Until the 21st century, a telephone network was developed which connects telephones all over the world. Because it is still based on real interconnection of lines, it is still referred to as „the fixed network“. In international jargon it is called the Public Switched Telephone Network PSTN (Public Switched Telephone Network).