In the 1870s, two inventors Elisha Gray and Alexander Graham Bell both independently designed devices that could transmit speech electrically (the telephone). Both men rushed their respective designs to the patent office within hours of each other; Alexander Graham Bell patented his telephone first. Elisha Gray and Alexander Graham Bell entered a famous legal battle over the invention of the telephone, which Bell won.

Alexander Graham Bell – Evolution of the Telegraph into the Telephone

The telegraph and telephone are both wire-based electrical systems, and Alexander Graham Bell’s success with the telephone came as a direct result of his attempts to improve the telegraph.

When Bell began experimenting with electrical signals, the telegraph had been an established means of communication for some 30 years. Although a phenomenally successful system, the telegraph, with its dot-and-dash Morse code was basically limited to receiving and sending one message at a time. Bell’s extensive knowledge of the nature of sound and his understanding of music enabled him to conjecture the possibility of transmitting multiple messages over the same wire at the same time. Although the idea of a multiple telegraph had been in existence for some time, Bell offered his own musical or harmonic approach as a possible practical solution. His “harmonic telegraph” was based on the principle that several notes could be sent simultaneously along the same wire if the notes or signals differed in pitch.

Alexander Graham Bell patented his telephone on the 14th of February 1876. The system consisted of a microphone and a speaker. The microphone was like a funnel, the wide end open and the narrow end pointing into a membrane connected to a rotor that followed the vibrations of the membrane. This vibrating rotor was connected to a coil to induce a voltage with the same frequency of the voice sent into the funnel. Bell’s microphone changed sound waves into a pulsating voltage which is faster and easier to transmit than sound waves. The speaker was made in similar fashion to the microphone.

Initially, nobody was interested in Bell’s invention. When he asked the Western Telegraph Company to buy his patent for $100,000, the response was “What shall we do with a toy like that?” this occurred in 1877. A few years later the same company offered him $25,000,000 for his patent but this time he was the one to refuse the offer. In contrast to other inventors Bell believed in the commercial use of his telephone system. He published his invention just after he had patented it. At the world exhibition in Philadelphia in 1876 he demonstrated his telephone and caused a sensation. On the 6th of October 1877, the Scientific American published Bell’s idea in a way it had not been realized so far. The invention itself was a long way from being put into practice but Bell’s communications system finally reached the public’s attention, despite many others having done similar experiments. There were about 30 other telephone systems patented within the following years.

One year after the invention, five banks in Boston ordered Bell’s telephone systems. These systems revealed several shortcomings. His telephone was better receiving than transmitting. The microphone was not sensitive enough. This was improved by David Edward Hughes’ (1831-1900) invention of the carbon microphone (1878) which was more sensitive.

In 1880 in the USA the telephone net had already 50 000 subscribers.

In all higher industrialized countries, the telephone soon became very popular. The speed of this development slowed down only during wars or economic crisis. In the following years telephony became more and more sophisticated. When you wanted to give somebody else a call, he or she had to talk to an operator first who made the connection manually on a connecting board. This took a long time as each individual telephone subscriber had to have his own socket which was connected and disconnected by hand. The manual exchange was the only way of making telephone calls until in 1889 Almon B. Strowger invented a system that allowed each individual telephone subscriber to establish their own telephone connections. Strowger was a funeral director who’s competition was quickly alerted upon news of deaths, their wives and daughters worked as telephone operators! Strowger vowed to eliminate the human element and set himself the task of building a simple automatic switch. Utilizing collar bones from his shirts, a makeshift auto-switch was produced. After enlisting the financial and technical help of his nephew, he managed to engage the interest of the American telephone companies.

This development made people more independent because they could dial themselves to establish their telephone connections. In 1892 A. B. Strowger founded his “Strowger Automatic Telephone Exchange Company” which was the world’s first telephone exchange without operators.