Each word is concluded by bringing the flag directly to the front, which motion is called 3.

Naval signalmen, generally apprentices, become very expert, and the rapidity with which they can wigwag sentences is really remarkable.
The Ardois system of night signalling consists of electric lights attached to the rigging.

There are four groups of double lamps, the two lamps in each group showing red and white respectively.

By the combination of these lights letters can be formed, and so, letter by letter, a word, and thence an order, can be spelled out for the guidance of the ships of a squadron.

The lamps are worked by a keyboard generally placed on the upper bridge.
The "flag hoist" system, as it is termed, consists of the displaying of different flags at some conspicuous place like the masthead.