Even with the caution Guglielmo Marconi displayed in this interview, there were a few technical errors in the comments, understandable in a technology that was only a few years old. According to the author, thunderstorms had no effect on the signals, but actually they were a major source of static interference. Marconi noted that they was no difference in operation during the day and night, which was true for short distances, but two years later he would find to his surprise that over long distances signals travelled much farther at night. And the inventor's belief that tuning would make it nearly impossible for unauthorized persons to intercept messages not intended for them bordered on wishful thinking, and would quickly be shown to be untrue.
Success, December 2, 1899, pages 3-4:
* MARCONI AND WIRELESS TELEGRAPHY *
The Famous Inventor Talks With a Representative of "Success" Regarding the Great Discovery Which Has Been Adopted by the United States Navy Department, and is to be Used by the British in the South African War
CHARLES H. GARRETT
THE reporting of the international yacht races by wireless telegraphy, by Chevalier Marconi, for the New York "Herald," has awakened general interest in America, in an invention that has worked successfully abroad for the past two years. "Telegraphy without a wire! How almost uncanny it seems! And what are its bounds? May it span the ocean?"
"I am averse to speaking of the possibilities of wireless telegraphy," said Chevalier Marconi, when I asked the question. "I will neither say such a thing is possible, nor impossible. It has always been my policy to accomplish a thing first, and to speak of it afterwards."
Chevalier Marconi is the Morse of wireless telegraphy. He does not lay claim to the discovery. But it is he who has perfected it, and made it of commercial value. He is only twenty-five years old, having been born at Griffore, near Bologna, on April 25, 1874. He was educated at Leghorn and at the University of Bologna, where he was graduated as an electrical engineer, and in England. He is slender, of an average height, and in manner, although he is affable, he appears prëoccupied. He has a long, well-shaped head; fine, light hair; and thoughtful blue eyes. He is nervous, and when he smiles, wrinkles collect around his mouth and eyes, and disappear quickly.
"I have always followed up scientific discoveries," he continued. "Even as a boy, I was always on the track of anything new. It was thus that I became interested in the discovery of wireless telegraphy by Hertz, of Germany.
"In 1893, Hertz demonstrated that waves propagated by electricity can be sent for thirty or forty yards, and can be recorded. Lodge detected their influence of seventy yards from the transmitter. It was then thought that a great distance could not be covered in this way. I erected poles on my father's estate near Bologna, and experimented; and through subsequent discoveries of my own, I was able to send messages from one pole to another, a distance of two miles." This occurred in 1895, when Marconi discovered that by connecting "one pole of a transmitter and one pole of a receiver to earth, and the other end to wires held vertically, the electric rays polarized at right angles to the surface of the earth, which then did not absorb them, as it did before, but left them free to go to a greater distance."
To speak more lucidly, a wire extended upward from a pole or a mast and connected with a transmitter at the bottom, will, through the discharge of electricity into the air, cause waves, or rays, that may be received and recorded by a similar wire at a distance.
"The whole principle," continued Marconi, "is that, if the wires are horizontal, the earth will collect the rays instead of the opposing perpendicular wire. The vertical wires are insulated. By tapping a Morse key on the transmitter, a spark is caused by the leaping of the electricity between two brass balls, the electricity jumps to the vertical wire, and instantaneously causes oscillations or rays.
"These are wave pulsations in the ether, and have nothing to do with the air.
"They journey in all directions in the same manner as circles on the surface of a pond, caused by the dropping of a stone; and they continue to journey till they are spent. Neither mountains nor artificial obstructions can stop them."
"Then they are light?"
"Yes, electrical rays, that the eye is unable to detect. But the vertical receiving wire catches them, a Morse instrument is influenced, and records dots and dashes."
"What is the necessity of a vertical wire one hundred and fifty feet high, or less," I asked, "if the rays are not stopped?"
"To allow for the curvature of the earth," replied Marconi. "A certain length of wire radiates them a certain distance. The rays, after journeying a certain distance, become faint, and do not influence the recorder. The electricity is generated by dry batteries. The more powerful the batteries, and the greater the 'spark gap,' the shorter may be the poles."
"Then, possibly, you may be able, in the near future, to do away with the poles altogether," I suggested.
"Already," he replied, "I have sent messages for two miles without using the elevated wires. But whether with prospective improvements I will be able to send messages great distances without them, I do not care to say. By continually improving the transmitter, and by making the recorder more sensitive, I have been able to shorten the vertical wire. At present, to send a message four times the distance, you must double the length of the vertical wires.'
The invention seems simple enough; still, Marconi said:--
"There is much that I do not understand. I know that by certain experiments I have produced certain results."
To describe the instruments briefly is not an easy task, yet one may give a general idea of the subject in a few words.
Mr. Marconi said: "To treat it scientifically, one would have to fill a book."
In the first place, there is a battery, consisting of, say, ninety-eight dry cells, which are connected, fourteen in a series, and joined in parallel with eight accumulator cells. These are joined to an induction coil, such as is used for the X-rays. In front of the coil are two brass spheres. The discharge of the coil passes between these two spheres. One sphere is connected with the earth, the other with the vertical wire, or conductor which flashes the message into space. The current is controlled by a Morse telegraphic key. When the key is pressed, a spark flashes between the two spheres, and they produce long, or short, effects, according to the duration of the pressure. For one dot, a single spark jumps; for one dash, a stream of sparks. Each spark indicates an oscillating impulse from the battery that actuates the coil.
The whole apparatus may be put on a four-foot table.
"As they reach the vertical wire attached to the receiving apparatus, similar, though weaker, oscillations are set up, and are communicated to the receiving instrument," by the aerial wire. This consists of a coherer, which is a small glass vacuum-tube, with two silver plugs in the top, about one thirteenth of an inch apart. Between these two plugs are silver and nickel filings. The electrical rays make the filings cohere, and transmit the waves to the other silver plug, which is connected with the home battery and the earth, thus completing the circuit.
"The circuit," said Marconi, "starts the battery by electro-magnetic induction, which works a Morse printing instrument. The battery also works a small hammer, which hits the glass tube a smart tap after each impulse, to decohere the filings, so as to restore them to their normal high resistance."
The peculiar fact about the coherer is, that it will only sympathize with Hertzian waves. No other electrical disturbances act upon it, not even those of a thunderstorm.
"And how is it affected by changes in atmospheric conditions?" I asked.
"Not even fog, rain, storm, hail or snow, night or day, varies its operation. At all times, and under all conditions, the electrical rays flash through space and intervening obstacles."
"And why may not other similar instruments receive the messages?" I asked.
"Because," replied Marconi, with a smile, "transmitters and receivers must be tuned to each other. One transmitter may be tuned for any number of receivers, within a regulated radius. For instance, a news agency may flash news to its subscribers within one hundred miles in all directions, and none but its subscribers can receive it, because others are not tuned to that particular transmitter."
"And this may apply to the stock quotations," I suggested, "to the police stations, mail offices, railroad stations, fire departments, signal service, to a naval squadron, and to many other cases where general news is to be conveyed?"
"But," I asked, "will it dispute the field of the general telephone?"
"On that question, I wish to keep silent. It would depend upon the number of tunings and on other things."
Here Marconi's manner led me to think that he had given the idea experimental attention.
"Can the transmitter be tuned to a certain length, or radius of wave?" I asked, "irrespective of the vertical wire?"
"It can be tuned to a certain length of wave, but the vertical wire must be taken into consideration," he replied, "for, under ordinary conditions, the distance that a wave may be sent depends largely on the height of a wire."
"Could you receive a message in this room without having a vertical wire fastened to a pole in the roof?"
"Yes, provided you could house a vertical wire corresponding to the vertical wire of the transmitter," he replied.
So its possibilities seem limitless.
"Can one vertical wire give forth and receive messages at the same time?"
"Not yet," he replied. "But the same wire may be used to receive or transmit messages, by disconnecting, for instance, the receiver, and putting on the transmitter. An understanding can be had to facilitate this. It is a very simple process.
Marconi's Invention Is Two Years Old
"You people over here do not seem to realize that my invention is two years old. It is working between Chelmsford, England, and Boulogne, France, a distance of one hundred and ten miles: between Dover and Bologne, thirty-two miles; between Dover and East Goodwin Lightship, eighteen miles; between Chelmsford and Harwich, forty miles; between Poole and the Isle of Wight, eighteen miles; and elsewhere; and between twenty places in Italy, and in all of these places continuously. Besides, other governments are considering it. The Italian navy has adopted it."
Chevalier Marconi received his title from the knighthood conferred upon him by the king of Italy, for his services to the world and to science.
Another invention in wireless telegraphy, by Marconi, is his wireless telegraphy by means of a parabolic copper reflector, with a Righi oscillator placed at the focus. In many ways, it is different from his other wireless telegraphic instruments. By this means, he is able to shoot a message in a narrow and direct line. It is caught by a circular, bowl-like reflector, which reports it to the receiver.
"Although I have not perfected this," said Marconi to me, "I have been able to send messages for four miles in a straight line, like a searchlight, except that you cannot see the rays. The advantages are obvious. A ship's mast equipped with a revolving reflector, or four revolving reflectors, would be able to flash messages of distress or warning to other ships, or to a lighthouse, which would be caught by receivers. The rays striking a particular receiver, would, through the battery, ring a bell and indicate the direction from which the signal came."
"Does the curvature of the earth affect this?" I asked.
How the Rays Shoot Off
"Yes," replied Marconi, "when the rays strike the surface of the water, they shoot off at an angle into space, but the elements have no effect whatever upon them.
"No, I will not speak of other possibilities of my inventions. I do not believe in theorizing. My wireless telegraphy was in operation in England for a month before I gave it to the public."
An interesting instance in connection with Chevalier Marconi's arrival in England is that, on his arrival, the custom house officials thought his instruments were infernal machines, and bombs, and destroyed them. But, not discouraged, Marconi set to work and had others made.
Mr. Goodbody, a director in the Wireless Telegraph and Signal Company, of Great Britain, and a close friend of Marconi, told me of the first demonstration of wireless telegraphy in England.
"Mr. Marconi," he said, "put the receiver in his cousin's room, and the transmitter in the bathroom of a London flat. One of us, a man, carried the receiver down stairs, and it kept ringing. He went to the street, and it kept ringing. He walked a few blocks, and still it rang. Finally, the man got into a cab and rode a couple of miles, and still it rang. The experiment was so convincing that I became interested."
"Have you any other inventions on hand, Mr. Marconi?" I asked.
"I am always at something," he answered, unaffectedly. "I have many ideas which I hope to realize, but I shall wait till I have perfected this."