-
Around 150 BC fire, often located for easier viewing in a tower a lighthouse, may have been used to indicate “safe” or “not safe.” Fire, lanterns, horns or bells were also used for shiptoship signals, announcing “come aboard” or “stay away.”
-
The ancient Greeks who investigated the magnetic properties of lode stone, observing how it attracted small pieces of iron. And by the fifth century BC the Greeks also noted that rubbing amber with fur resulted in the amber’s ability to attract small objects, thus giving us terms like “electric” which are based on the Gre ek word for amber -“elektron.”
-
By 1600 William Gilbert described properties of magnetic forces.
-
The eighteenth century saw various experiments on eletrical force including studies of electrical current the flow of electrical charge by B. Franklin among others.
-
But the study of electrical currents really took off after the invention ofthe voltaic cell (battery) by alessandro volta in 1800.
-
Further interconnections were made with the di scovery in 1820 by Hans Christian Oersted that compass needles were deflected by nearby electric currents and, soon after, William Sturgeon found that he could make a strong magnet, now called an electromagnet, by winding wire around a piece of nonmagneti zed iron and connecting the wire across a battery. Thus, charges were seen to produce electric effects and, in addition, moving charges were seen to produce magnetic effects.
-
In 1831 Michael Faraday in England and, ind ependently, Joseph Henry in the United States demonstrated they could create a current in wires without batteries as long as the wires were in the vicinity of a changing magnetic field.
-
In 1844 the first long distance message was sent from Washington, DC to Baltimore, MD and by 1866 the first transatlantic cable connected the United States and Europe.
-
In 1864 James Clerk Maxwell combined the mathematical connections among charges, currents and electric and magnetic fields into four equations and he re alized that the solution to those equations is an electromagnetic wave that travels at the speed of light.
-
In 1888, Heinrich Hertz experimentally verified the existence of these waves when he demonstrated that they could be produced by a spark and receive d by a distant coil of wire. These were originally called Hertzian waves but are now known as radio waves, part of the electromagnetic spectrum.
-
Although we now know that rubbing amber with fur results in the transfer of subatomic charged particles we call electrons and that electrical phenomena are due to forces by and on these particles, electrons weren’t discov technology was well on its way before then.
-
The name most associated with wireless telegraphy is Guglielmo Marconi whose skill rested in making important improvements to what had come before. These improvements, beginning in 1895, greatly increased the distance with which signals could be sent, with shiptoshore transmission demonstrated in 1899.
-
the Giangantic Ship was seat to sea.
-
Were sent to Titanic Captain Edward John Smith, including one at about 5p.m. on the 14th from the California. But at 11:15 that evening, Phillips was deeply involved with relaying a large number of passenger messages to Cape Race, Newfoundland and when the California sent the message “We are stopped and surrounded by ice,” Phillips replied “Shut up. I’m busy. I am working on Cape Race.”
-
But even in this electronic age, the "International Regulations for the Prevention of Collision at Sea" established by the International Maritime Organization include references to s uch distress signals utilizing bells, gongs, foghorns, signal flags as well as signal lamps that flash messages via Morse code.
