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Semaphore, system of visual signaling using flags or lights to represent letters and numbers. The first such system was introduced by Claude Chappe (1763–1805) used 5–10 mi (8–16 km) apart. Semaphore is still used for signaling between ships and on some railroads.

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21st Century Webster's Family Encyclopedia21st Century Webster's Family Encyclopedia - Sato, Eisaku to Serra, Junípero