History
The use of radio to aid in rescuing survivors of accidents at sea came to the forefront after the sinking of the RMS Titanic in 1912. Lifeboats were equipped with spark gap transmitters such as the Marconi Type 241, c. 1920. These operated using Morse code on 500 kHz, the international distress frequency at the time. This frequency had the advantage of long range due to ground-wave propagation and was constantly monitored by all large ships at sea after the Titanic's sinking. However, due to its wavelength of 600 meters, a long antenna was required to achieve good range. Long wires on the order of 1/4 wavelength held up by kites or balloons were often used. Spark-gap continued to be used in lifeboats long after the technology was banned for general communication.
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“We know only a single science, the science of history. One can look at history from two sides and divide it into the history of nature and the history of men. However, the two sides are not to be divided off; as long as men exist the history of nature and the history of men are mutually conditioned.”
—Karl Marx (1818–1883)
“All things are moral. That soul, which within us is a sentiment, outside of us is a law. We feel its inspiration; out there in history we can see its fatal strength.”
—Ralph Waldo Emerson (1803–1882)
“History ... is, indeed, little more than the register of the crimes, follies, and misfortunes of mankind.
But what experience and history teach is this—that peoples and governments have never learned anything from history, or acted on principles deduced from it.”
—Georg Wilhelm Friedrich Hegel (1770–1831)