Optical telegraph
From Wikipedia, the free encyclopedia
Optical telegraph refers to a system of telecomunication using visual means of transmission. Types of systems include Semaphore, Aldis lamps, Heliograph, Ships flags and Smoke signals.
Optical telegraph refers to a system of telecomunication using visual means of transmission. Types of systems include Semaphore, Aldis lamps, Heliograph, Ships flags and Smoke signals.