The telegraph

The telegraph was the first form of telecommunication. 'Telegraph' means 'writing from far away' or 'distant writing' and the word originally applied to semaphore systems. But the search for ways of sending signals over long distances had been around for thousands of years.

The first telegraph systems were developed thousands of years ago. They used many different ways of signalling: smoke, fiery beacon, drums, lights, mirrors, flags and semaphores. But the basic idea was always the same - transmit a message faster than a man could run or a horseman could ride. The limitations were always the same, too. Signals had to be relayed in stages defined by how far a human could see or hear. And the signals had to be simple, or in a code.

An ancient telegraph : fire and water

The first recorded telegraph was built by a Greek military author named Aeneas around 350 BC. Aeneas was frustrated by the limitations of beacon signals - you can only signal that something has happened, not what has happened. He used water to add time division - allowing different messages to be sent.

A flaming torch gave the start signal for both sender and receiver to allow the water to run out of out of identically sized vessels in which corks were floating, with rods attached.
As the water went down, so would the rods, each marked with a series of possible messages.
When the desired message aligned with the rim of the jar, the sender would signal again with the torch, and the other station to replace the bung. The receiver would then read off the message shown on the rod.
The Roman historian Polybius (ca. 200-118 BC) says this 'hydraulic telegraph' was used to send military messages from Sicily to Carthage during the First Punic War (264-241 BC).

Chappe's semaphore telegraph (1793) : the first national telegraph system

In the late 18th century, the Chappe brothers in France did much to develop the visual telegraph - in a series of machines designed to send messages quickly over long distances. Remarkably, they managed to do so during the turmoil of the French Revolution and the Reign of Terror (one of their early models was burned by the Paris mob).
In 1793, Chappe demonstrated his ultimate 'tachygraphe' - a system of semaphore arms that could quickly be manipulated to form different shapes.
The Chappe semaphore system was used to set up a telegraph network that spanned the whole of Napoleon's empire, and was still in use by the French military as late as the Crimean War - nearly 20 years after the electric telegraph had arrived.