Wireless Signaling in Ancient Times
‘Wireless communication is as old as Biblical times’
( John Kingman — National Geographic Society 1919)
When we think of present-day wireless applications our mind only goes as far back as the early seventies when they started becoming widely known to the general public. Wireless communication giants like T-Mobile that have already launched the one and only massive nationwide 5G network covering almost all United States seem like normal today.
Who can forget the amazement that we felt in witnessing a Motorola engineer Martin Cooper making the world’s first ever wireless phone call on April 3rd, 1973 from Sixth Avenue in New York city. The wireless phone resembled a heavy brick. This spectacle caught our imagination — a phone call without wires!
The wireless revolution really caught on in the nineties and suddenly this was an invention that no one could live without.
Nowadays mobile phones, smart watches, tablets and countless wireless gadgets are ubiquitous and are considered a must have part of modern life. But wireless signaling is not new and has been with us for centuries — even thousands of years. Consider.
Lighthouses and beacon fires figure prominently in Bible verse. Although they conveyed different meanings in their respective verses but their appearance in Bible nevertheless gives an idea about the widespread awareness that the masses had at the time. Beacon fires for signaling were in use during the times of early Greeks. Heliographs which are considered the very first wireless telegraphs using flashes of sunlight reflected by a mirror were employed by Greeks in their many wars of conquest. First recorded use of heliographs as an optical communication device occurred during the Battle of Marathon (490 BC) when the Persians invaded Greece. Greeks faced a massive Persian force many times their size and employed every advantage available in their arsenal. Famous Greek writers like Herodotus, Virgil and Aeschylus frequently alluded to the use of signaling as a common military practice among the ancients. A much smaller Greek force routed a numerically superior Persian army in the Battle of Marathon by employing advanced military tactics and cutting edge optical signaling.
Herodotus in his writings mentions an interesting case of long distance signaling in which it appears that messages were sent to Xerxes (Persian Emperor 519–465 BC) in Asia by means of a line of beacon fires arranged through the Greek islands.
Recorded history tells us about the widespread use of signaling mirrors employed by Archimedes during the siege of Syracuse in Sicily (397 BC). Historians postulate about the dual use of these mirrors — as signaling devices and as a weapon. They might not have been able to set the sails of the invading ships on fire but could have used these to signal allies for help. An ancient story tells us about Alexander the Great use of such mirrors for signaling.
‘Alexander the Great placed on the top of the tower a mirror constructed with so much art that by means of it he could see the fleets of his enemies at 100 leagues distant.’
Ancients not only signaled by mirrors but were technologically advanced enough to employ codes. Polybius (Greek historian 208–125 BC) goes into considerable detail in describing an ingenious and elaborate method invented by Cleoxenus and Democlitus that was later perfected by Polybius himself — known as the ‘Polybius Checkerboard’. Polybius did not originally intend this device as a cipher so much as an aid to telegraphy.
Briefly this ‘Polybius Checkerboard’ worked as follows, the letters of the alphabet were arranged in five boards. To send any letter, such as Sigma (∑), the signaling party raised three torches because Sigma is in the third column. Next, four torches were raised as Sigma is the fourth letter in the column. This is how this signaling cipher worked in brief. This system was effective at about ten miles and although it was designed for torches it could easily be modified for mirror signaling (by flashes). This would have made it possible to extend it to daylight hours as well.
It would seem likely that Romans, a century and a half later could have perfected this by use of mirrors. This form of mirror signaling was in use by American Indians with the Chief frequently been able to direct his warriors with certainty from a distant hill overlooking the battlefield.
Capri island in Sicily became famous as the world’s first ‘wireless station’. Tacitus — Roman senator and historian refers to this long distance signaling during the reign of Tiberius in his works. Second Roman emperor Tiberius assumed the throne after his stepfather and the first Roman emperor Augustus died. He ruled over the vast Roman empire for twenty-three years till his death (14–37 AD). In the last years of his reign he retired to the island of Capri in the southern portion of modern Italy. According to Tacitus, it was imperative for Tiberius to receive regular updates from Rome in order to control the day to day running of the empire. The way he may have achieved this was by use of signaling towers atop carefully selected mountains that litter the Italian landscape.
Capri island was the world’s first wireless station
The distance between Rome and Capri as the crow flies is about 130 miles — too long for signaling with mirrors. But strategically located mountaintops along the coast of Tyrrhenian Sea afford an opportunity from where the signals can be relayed.
According to historians a suggested line of stations with ranges less than 44 miles can be speculated. This can be attempted in the following way;
Rome to Monte Cavo (18 miles); then to Monte Circeo (39 miles); then to Monte Massico (44 miles); then finally to Capri (44 miles).
People have long suspected that Palatine Hill — the highest point in Rome was the ‘sending station’. The mirror system would cost no money to operate and would be easy to use. In adverse weather conditions the primitive beacon fires would have to be used when there was no sun. Tiberius lived in Capri for the last eleven years of his reign as Caesar and put down many revolts without even setting foot in Rome. Science, not fate was helping him.
History is littered with examples like these about the ingenuity of ancients. Earliest signaling may have started soon after humans discovered fire. It is amazing that some of the ancient’s methods of signaling were still used till the beginning of the century. In England and other places, the exposed fire beacons of the ancients were still used till 1816. Present day optical and digital signaling may appear indistinguishable from magic to the ancients. We have come a long way, but it all started when some human looking at the smoke rising from a fire started thinking.
References
1. The Isle of Capri: An Imperial Residence and Probable Wireless Station of Ancient Rome (By John Kingman — The National Geographic Society 1919)
2. Heliograph and Mirrors by Daniel Woods (Military Communications: From Ancient Times to the 21st Century)
3. The Battle of Marathon by Peter Krentz (2010 Yale University)
4. The Shield Signal at the Battle of Marathon by P.K. Baillie (Journal of Hellenic Studies 1919)
5. The Ancient Engineers by L Sprague De Camp (1993 Edition)
6. Wikipedia — Various sources and topics
