Semaphore

[2][3] A semaphore can be performed with devices including: fire, lights, flags, sunlight, and moving arms.

In 1867, then Captain, later Vice Admiral, Philip Howard Colomb for the first time began using dots and dashes from a signal lamp.

[6] The modern lighthouse is a semaphore using a tower, building, or another type of structure designed to emit light from a system of lamps and lenses and to serve as a navigational aid for maritime pilots at sea or on inland waterways.

Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation.

Originally lit by open fires and later candles, the Argand hollow wick lamp and parabolic reflector were introduced in the late 18th century.

The advent of electrification and automatic lamp changers began to make lighthouse keepers obsolete.

[9] It is still used during underway replenishment at sea and is acceptable for emergency communication in daylight or using lighted wands instead of flags, at night.

They are brightly coloured and easily distinguishable, serving purposes such as spelling out messages, identifying letters and numbers, signalling distress or requests for assistance and communicating nautical procedures.

[10] The heliograph was a simple but effective instrument for instantaneous optical communication over long distances during the late 19th and early 20th century.

This early form of telegraph system was much more effective and efficient than post riders for conveying a message over long distances.

In 1837, the British inventors William Fothergill Cooke and Charles Wheatstone obtained a patent for the first commercially viable telegraph.

Telecommunication evolved replacing the electric telegraph with the advent of wireless telegraphy, teleprinter, telephone, radio, television, satellite, mobile phone, Internet and broadband.