Preece carried his experiments much further. In 1885 he laid out two great squares of insulated wire, a quarter of a mile to the side, and at a distance of a quarter of a mile from each other. Telephonic communication was established between them, and thus he had attained wireless telephony by induction. In 1887, another Englishman, A.W. Heaviside, laid circuits over two miles long on the surface and other circuits in the galleries of a coal-mine three hundred and fifty feet below, and established communication between the circuits. Working together, Preece and Heaviside extended the distances over which they could communicate. Preece finally decided that a combination of conduction and induction was the best means of wireless communication. He grounded the wire of his circuit at two points and raised it to a considerable height between these points. Preece's work was to put the theories of Professor Trowbridge to practical use and thus bring the final achievement a step nearer.
But conduction and induction combined would not carry messages to a distance that would enable extensive communication. A new medium had yet to be found, and this was the work of Heinrich Hertz, a young German scientist. He was experimenting with two flat coils of wire, as had many others before him, but one of the coils had a small gap in it. Passing the discharge from a condenser into this coil, Hertz discovered that the spark caused when the current jumped the gap set up electrical vibrations that excited powerful currents in the other coil. These currents were noticeable, though the coils were a very considerable distance apart. Thus Hertz had found out how to send out electrical waves that would travel to a considerable distance.
What was the medium that carried these waves? This was the question that Hertz asked himself, and the answer was, the ether. We know that light will pass through a vacuum, and these electric waves would do likewise. It was evident that they did not pass through the air. The answer, as evolved by Hertz and approved by other scientists, is that they travel through the ether, a strange substance which pervades all space. Hertz discovered that light and his electrical waves traveled at the same speed, and so deduced that light consists of electrical vibrations in the ether.
With the knowledge that this all-pervading ether would carry electric waves at the speed of light, that the waves could be set up by the discharge of a spark across a spark-gap in a coil, and that they could be received in another coil in resonance with the first, the establishment of a practical wireless telegraph was not far away.
XVI
AN ITALIAN BOY'S WORK
The Italian Youth who Dreamed Wonderful Dreams—His Studies—Early
Detectors—Marconi Seeks an Efficient Detector—Devises New Sending
Methods—The Wireless Telegraph Takes Form—Experimental Success.
With the nineteenth century approaching its close, man had discovered that the electric waves would travel through the ether; he had learned something of how to propagate those waves, and something of how to receive them. But no one had yet been able to combine these discoveries in practical form, to apply them to the task of carrying messages, to make the improvements necessary to make them available for use at considerable distances. Though many mature scientists had devoted themselves to the problem, it remained for a youth to solve it. The youth was Guglielmo Marconi, an Italian.
We have noticed that the telegraph, the cable, and the telephone were the work of those of the Anglo-Saxon race—Englishmen or Americans—so it came as a distinct surprise that an Italian youth should make the next great application of electricity to communication. But Anglo-Saxon blood flows in Marconi's veins. Though his father was an Italian, his mother was an Irishwoman. He was born at Villa Griffone near Bologna, Italy, on April 25, 1874. He studied in the schools of Bologna and of Florence, and early showed his interest in scientific affairs. From his mother he learned English, which he speaks as fluently as he does his native tongue. As a boy he was allowed to attend English schools for short periods, spending some time at Bedford and at Rugby.
One of his Italian teachers was Professor Righi, who had made a close study of the Hertzian waves, and who was himself making no small contributions to the advancement of the science. From him young Marconi learned of the work which had been accomplished, and of the apparatus which was then available. Marconi was a quiet boy—almost shy.