U.S. #1500 pictures Marconi’s spark coil and spark gap, which enabled him to transmit across the Atlantic Ocean by wireless radio.

First Transatlantic Radio Transmission

On December 12, 1901, Guglielmo Marconi successfully sent the first radio transmission across the Atlantic Ocean.

Born in Italy in 1874, Marconi was a physicist before he became interested in the transmission of radio waves. He ran his first experiments in Bologna in 1894. Soon, Marconi was able to send radio signals up to one-and-a-half miles. However, many of his contemporaries in Italy didn’t see the merit in his experiments, so Marconi moved to England in 1896.

After settling into his new home, Marconi established a wireless telegraph company. By this point, he was able to send radio transmissions over 10 miles. And in 1899 Marconi hit a major milestone – he sent a transmission across the English Channel from two points over 27 miles apart. That same year, Marconi outfitted two U.S. ships with his technology to transmit the progress of the America’s Cup yacht race back to newspapers in New York. This sparked widespread interest in his wireless company.

U.S. #890 – Marconi’s first radio message used Morse Code, which was created by Samuel Morse in the 1830s.

By the turn of the century, Marconi was convinced that radio waves could be transmitted over much longer distances. Many disagreed, citing that the waves wouldn’t travel along the earth’s curvature. He set out to prove them wrong. In 1901, Marconi set up two radio stations – one in Cornwall, England and the other in Newfoundland, Canada – some 2,000 miles away. On December 12, Marconi floated a kite above the station in Canada and waited at the receiver. At about 12:30 in the afternoon, he received a signal from his assistants at the England station. It was a series of three “pips” – Morse code for the letter “S.” Marconi excitedly called over his assistant, George Kemp, who confirmed he heard the weak signal as well. They heard it two more times that day and another 11 the next day.

While Marconi had succeeded, the skeptics were also right. The signal couldn’t travel along the curvature of the earth. Instead, the waves traveled into the upper atmosphere and bounced back down. In fact, Marconi’s experiment led Arthur Kennelly and Oliver Heaviside to suggest a layer of ionized air existed in the upper atmosphere. Today we call this the ionosphere.

Some doubted Marconi’s claim, as the only witness was his personal assistant. He repeated the experiment two months later, with additional witnesses, and received an even stronger signal.

According to Marconi, “The result meant much more to me than the mere successful realization of an experiment… I now felt for the first time absolutely certain that the day would come when mankind would be able to send messages without wires not only across the Atlantic but between the farthermost ends of the earth.” And he was right. This “wireless telegraphy” led to the widespread use of radio around the world.

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  1. Isn’t it amazing how far we have come, from some three feint dots to instant voice and video anywhere anytime, Wow!

  2. I’m going to send a copy to my grandsons. They should realize how it is that modern technology of that sort got its start: some imagineering and quite a lot of persistence. And, how recent it was: my own father was born in 1898, altho they never knew him.

  3. Physics is an interesting and challenging part of science. Over time, we have learned to change energy from one source to another, from heat to light to sound, etc. We have progressed from the early smoke signal to discoveries in the extremes of space but even to this day we still have trouble communicating with each other.

    1. Stu Hoyt, excellent point. Do you notice that the science community disregards philosophical disagreements (religion, politics) in favor of the progressive common goal? There is something there to be learned.

  4. Marconi was a path setting physicist. Truly a difference maker. It seems that today individuals are not the pioneers, but groups such as NASA or Universities around the world. Interesting history.

  5. Look where we are today. Amazing! All from the mind, inventiveness, temerity and persistence of this incredible man. Thanks for sharing this information, Mystic, through TDIH.

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