Optical telegraph
From Free net encyclopedia
Optical telegraph refers to a system of telecomunication using visual means of transmition. 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 transmition. Types of systems include Semaphore, Aldis lamps, Heliograph, Ships flags and Smoke signals.