"We picture inventors as heroes with the genius to recognize and solve a society's problems. In reality, the greatest inventors have been tinkerers who loved tinkering for its own sake and who then had to figure out what, if anything, their devices might be good for." Jared Diamond
On March 10, 1876, in Boston, Massachusetts, Alexander Graham Bell invented the telephone. Thomas Watson fashioned the device itself; a crude thing made of a wooden stand, a funnel, a cup of acid, and some copper wire. But these simple parts and the equally simple first telephone call -- "Mr. Watson, come here, I want you!" -- belie a complicated past. Bell filed his application just hours before his competitor, Elisha Gray, filed notice to soon patent a telephone himself. What's more, though neither man had actually built a working telephone, Bell made his telephone operate three weeks later using ideas outlined in Gray's Notice of Invention, methods Bell did not propose in his own patent.
" . . . an inspired black-haired Scotsman of twenty eight, on the eve of marriage, vibrant and alive to new ideas." Alexander Graham Bell : The Life and Times of the Man Who Invented the Telephone
Intrigue aside for now, the story of the telephone is the story of invention itself. Bell developed new and original ideas but did so by building on older ideas and developments. Bell succeeded specifically because he understood acoustics, the study of sound, and something about electricity. Other inventors knew electricity well but little of acoustics. The telephone is a shared accomplishment among many pioneers, therefore, although the credit and rewards were not shared equally. That, too, is often the story of invention.
Telephone comes from the Greek word tele, meaning from afar, and phone, meaning voice or voiced sound. Generally, a telephone is any device which conveys sound over a distance. A string telephone, a megaphone, or a speaking tube might be considered telephonic instruments but for our purposes they are not telephones. These transmit sound mechanically and not electrically. How's that?
Speech is sound in motion. Talking produces acoustic pressure. Speaking into the can of a string telephone, for example, makes the line vibrate, causing sound waves to travel from one end of the stretched line to the other. A telephone by comparison, reproduces sound by electrical means. What the Victorians called "talking by lightning."
A standard dictionary defines the telephone as "an apparatus for reproducing sound, especially that of the voice, at a great distance, by means of electricity; consisting of transmitting and receiving instruments connected by a line or wire which conveys the electric current." Electrical current 1) operates the telephone and 2) your voice varies that current to communicate. With those two important points established, let's look at telephone history.
The telephone is an electrical instrument. Speaking into the handset's transmitter or microphone makes its diaphragm vibrate. This varies the electric current, causing the receiver's diaphragm to vibrate. This duplicates the original sound. Take a look at this image to make this point much more clear.
Modern telephones don't use carbon in their handsets. They use electret microphones for the transmitter and piezoelectric transducers for receivers but the principle described in the image linked above is the same. Sound waves picked up by an electret microphone causes "a thin, metal-coated plastic diaphragm to vibrate, producing variations in an electric field across a tiny air gap between the diaphragm and an electrode."[Britannica definition] A piezoelectric transducer uses material which converts the mechanical stress of a sound wave upon it into a varying electrical signal.
Telephone history begins at the start of human history. Man has always wanted to communicate from afar. People have used smoke signals, mirrors, jungle drums, carrier pigeons and semaphores to get a message from one point to another. But a phone was something new. Some say Francis Bacon predicted the telephone in 1627, however, his book New Utopia only described a long speaking tube. A real telephone could not be invented until the electrical age began. And even then it didn't seem desirable. The electrical principles needed to build a telephone were known in 1831 but it wasn't until 1854 that Bourseul suggested transmitting speech electrically. And it wasn't until 22 years later in 1876 that the idea became a reality. But before then, a telephone might have been impossible to form in one's consciousness.
While Da Vinci predicted flight and Jules Verne envisioned space travel, people did not lie awake through the centuries dreaming of making a call. How could they? With little knowledge of electricity, let alone the idea that it could carry a conversation, how could people dream of a telephonic future? Who in the fifteenth century might have imagined a pay phone on the street corner or a fax machine on their desk? You didn't have then, an easily visualized goal among people like powered flight, resulting in one inventor after another working through the years to realize a common goal. Telephone development instead was a series of often disconnected events, mostly electrical, some accidental, that made the telephone possible. I'll cover just a few.
There are many ways to communicate over long distances. I have reproduced a nice color diagram which shows the Roman alphabet, the international flag code, Morse Code, and semaphore signaling. Click here to view