Trying to trace the history of early communication is rather difficult; prior to modern communication devices, there is little recorded history of how civilizations and individuals transfered ideas over long distances. There are, however, some similarities between all forms of communication;
1. A “transmitter”, which takes information and converts it into signal
2. A “transmission medium”, through which the signal travels, and
3. A “receiver”, which converts the signal back into useful information.
While there is no concrete evidence, the first form of telecommunication (that is, communicating at a distance further than shouting) was probably percussion based, at least in forested areas. Africa is the home of “talking drums”, although a form of drum communication was also used in South America, and European explorers were often stunned to discover that information about their arrival would travel far faster than even the swiftest messenger. The transmitter, in this case, was a hollowed log and was struck with a stick in a simple pattern (often repeated) that would correspond to a message: “Under attack”, “Strangers approaching”, directions, warnings… as long as the listener knew the pattern being played, a wide variety of simple messages could be sent quickly. These early devices often had ranges of about 8 km (5 miles), and interesting or important messages would be “passed along” by the next village or way station equipped with such a drum.
Smoke signals, developed and used in both America and China, used optical receivers (that is the eye) instead of auditory ones. By covering a fire with a blanket, a small amount of smoke is stored and then released, forming a “puff” of smoke. With practice, the frequency and length of each puff of smoke can be controlled, and used to transmit simple signals. Since smoke signals used optical receivers, they were normally placed in areas with long horizons; the flatlands and stone bowls of America, and the towers of the Great Wall of China.
Semaphores, also called “optical telegraphs”, were another form of early telecommunication. By placing mechanical components in specific positions, signals are transmitted to the receiver; the best known semaphores are the flags used on ships, in which the transmitter holds two flags and places them at various places around himself, each position corresponding to a message. Optical semaphore towers predated electrical telegraph lines, the first proposed by an English scientist (Robert Hooke) in 1684. France had a network of semaphore towers covering the entire country by the late 1700s, with 556 stations over 4,800 kilometers, and used it for national and military communication until 1850. Competition with electrical telegraphs would eventually force semaphores out of business; it cost nearly 10 times more to send a message via semaphore than it did by telegraph.
The first commercial telegraph (using pulses of electrical power to cause a small hammer to tap out a message) was created in 1839 by two Englishmen, followed shortly by the invention of a code for transmission by Samuel Morse (named, unsurprisingly, the Morse Code). The first transatlantic telegraph line was completed in 1866, allowing the first direct communication between the New and Old World.
1876 saw the simultaneous (and independent) invention of the telephone by Alexander Bell and Elisha Gray. This device directly transforms audio signal into electrical signal, which is transmitted over a wire and then converted back into audio signal.
The last significant “early” form of communication was in 1901, when G. Marconi established wireless communication between St. John’s, Newfoundland (Canada) and Poldhu, Cornwall (England). Radio communication had already been demonstrated by Nikola Tesla, but Marconi took his demonstration principles and made the world’s first operational radio, transforming audio signal into radio waves (which were then received and transformed back into audio signals).