What is visual signaling?

Some articles on visual, visual signaling, signaling:

Signal Corps (United States Army) - Early History
... He proposed that the Army use his visual communications system called "wig-wag", or "aerial telegraphy", while serving as a medical officer in Texas in 1856 ... Major Myer first used his visual signaling system on active service in New Mexico during the 1860–1861 Navajo expedition ... Using flags for daytime signaling and a torch at night, wigwag was tested in Civil War combat in June 1861 to direct the fire of a harbor battery at Fort Wool against the Confederate positions opposite Fort Monroe ...

Famous quotes containing the word visual:

    Nowadays people’s visual imagination is so much more sophisticated, so much more developed, particularly in young people, that now you can make an image which just slightly suggests something, they can make of it what they will.
    Robert Doisneau (b. 1912)