THROUGHOUT HISTORY, groups and individuals have needed to communicate with one another secretly. Governments’ secret services work undercover to investigate covert activities in their own and other countries. During wartime, military information becomes a vital weapon and spies and intelligence gatherers are kept busy trying to discover the enemy’s next move. In war and peacetime, information needs to be communicated to colleagues without falling into the wrong hands. Sometimes, the best way to communicate secretly is to conceal the method of communication. In other cases, transmissions are coded so that they are unrecognizable to the enemy.
MESSENGER PIGEONS – Specially trained pigeons have been used to deliver secret messages since Julius Caesar (100–44 B.C.) used them during his campaigns in France. During World War II, the Allies used half a million pigeons to carry secret messages in tiny canisters attached to their legs.
ELIZABETHAN INTRIGUES – This portrait of Queen Elizabeth I of England contains a symbol of the activities of her secret service — the eyes, ears, and lips that decorate her dress. During her long reign (1558–1603), Elizabeth came under threat from various opponents, who planned to overthrow her and take the throne. Thanks to the activities of her secret service, all the plots against her were discovered and Elizabeth remained queen until her death.
DECIPHERING A CIPHER – Cipher wheels are one way of making messages unintelligible to anyone except the intended receiver. Letters or numbers are replaced with other letters or numbers by following the settings on the wheel. To decode the message, the receiver must know which setting of the cipher wheel has been used.
French biscuit tin
HIDDEN RADIO – This MCR 1 radio receiver, built during World War II, was used by members of the French resistance. It was fitted into a common biscuit tin (above) to disguise it from German forces during house searches. When the coast was clear, the components were quickly put together and tuned to British broadcasts. Many regular British radio programs — from dramatizations to weather forecasts — contained coded messages intended for resistance agents. – Power supply connectors
RADIO WRISTWATCH – This wristwatch was used during the 1980s by the Soviet secret service, the KGB, to monitor the movements of its spies. On its tiny screen, the watch displayed prearranged coded messages, sent in the form of radio signals. The spy wore a tiny radio receiver on his body that vibrated to let him know an incoming message had arrived.
Minox camera, shown actual size
MINOX MINI CAMERA – The Minox camera was invented by the Latvian engineer Walter Zapp in 1938. The camera is just over 3 in. (79 mm) long and uses special film a quarter of the size of standard 35 mm film. Although not developed especially for espionage, Minox cameras quickly became standard tools for spies. The fictional British spy James Bond was seen using one in the 1979 film Moonraker.
BUG IN A PLUG – A bug that fits inside an ordinary household plug adapter can be used to pick up sounds and transmit them to a listening station. The bug uses power from the outlet itself, so it can continue transmitting indefinitely if it is not detected.