Morse Code, named after inventor Samuel Morse, was the main type of high speed communication in the late 19th century and the first half of the 20th century. Though initially used with the telegraph, Morse Code can also be used effectively to communicate via flashing lights or repeated sounds. Although rapidly fading from usage, it is still popular with amateur radio operators and airline pilots must be familiar with it.JRG Beavon: Morse Code
SOS
Despite common misconceptions, SOS does not stand for "Save Our Ship" or "Save Our Souls". The sounds are easiest to hear through static, which is why they were selected as the standard international distress call. Though adopted in 1908 as the standard distress calls, others were also in use until shortly after the Titanic sinking on April 15, 1912