Guglielmo Marconi, inventor of wireless telegraphy and pioneer of radio communication, was born on April 25, 1874.

Born into a wealthy family with Italian and Irish roots, he never pursued higher education as he was a poor student, but from an early age he showed an affinity for science and electricity. 

His daughter Degna, in her book about her father (My father, Marconi), recounts, among other things, his early experiments, which eventually led to the invention of wireless telegraphy: 

In the period 1894-1895 Guglielmo lived with his family in the commune of Pontecchio, just outside Bologna. Having converted the attic of the house into a laboratory, he experimented with wireless message transmission, influenced by the work of physicists James Maxwell, Heinrich Hertz and Oliver Lodge. Such was his dedication that his mother was forced to leave food outside the closed door for him, as he rarely left the room.

During a visit by his four cousins, the locked door of the laboratory piqued the curiosity of the girls, who persistently demanded that he allow them to enter. Guglielmo, with much ado, submitted, but the sight they beheld left them rather indifferent: jars and pots filled with water and two curved planks of wood covered with tin.

Faced with his cousins' questions, Guglielmo explained that they were reflectors. Daisy, the youngest of them and his favourite, not understanding their usefulness wondered: "And what exactly did you discover?".

"Do you see the needle?", Guglielmo asked her. "Watch it now while I put it on the table." He then took a nautical compass and placed it on the opposite side of the room. "Now watch Daisy. I'm going to make the needle move without touching it".

Daisy laughed, knowing that her cousin used to do various magic tricks to impress her. Guglielmo then sat in front of a pear-shaped electronic bowl that emitted a blue light, and as soon as she touched it the needle and the compass began to move simultaneously.

This time his magic was very easy to explain: a wire, as long as a hair, connected the needle and the compass. Daisy caught it and dragged it between her fingers, Guglielmo looking at her in embarrassment. The girls didn't understand what exactly they were watching, but they were visibly impressed.

The show in the attic had turned into Daisy's personal triumph. Years later Guglielmo would tell Degna that he hated revealing his secrets and this secret he kept locked away in his little makeshift workshop was the most important secret of his life.   

Photo

Guglielmo Marconi with the spark-gap transmitter (right) and coherer receiver (left) he used in some of his first long distance radiotelegraphy transmissions. (Image reproduction rights: Wikimedia Commons)