semaphore signal

释义

手旗通信，塔上信号，杆上信号；

Semaphore-signal
Semaphore-signal
Semaphore signal
Railway Signal
Railway Semaphore Signal
International maritime signal flags
Railway semaphore signal
ALEUT SEMAPHORE SIGNALS
A man standing barefoot on a plank of wood painting a semaphore railway signal, with a man on ladder and a supervisor standing below...
Semaphore signals
SEMAPHORE SIGNALS DANCE UMBRELLA'S OPENING
THE COAST SIGNAL STATIONS AND THE SEMAPHORE TELEGRAPH
Fear of the unknown: a history of wireless ... Part one: in an era where battlefield Signals were passed on by semaphore, heliograph...