In ancient times, according to one story, a chain of fi res on mountaintops was used to relate the news of
the fall of Troy to people in Greece. In the past, native people in the Americas used smoke from fi res to
transmit messages. They developed a code—in which certain combinations of smoke rising had special
meanings. For example, two parallel columns of smoke indicated the successful return of a war party.
Almost anything that makes a noise has been used for signaling. Cyrus, an ancient Persian ruler,
established lines of signal towers. At each one, people with powerful voices shouted a message to the
next tower, and in this way, news and information was passed on through the kingdom. A kind of
drum talk is still used in Central Africa today, although few who are not natives have been able to
understand it. The sender uses a drum that can produce a high or low tone. Because the local dialect
alternates in these tones, the sender is able to simulate speech with the drums.