Signor Marconi’s Magic Box: The invention that sparked the radio revolution. Gavin Weightman. Читать онлайн. Newlib. NEWLIB.NET

Автор: Gavin Weightman
Издательство: HarperCollins
Серия:
Жанр произведения: Биографии и Мемуары
Год издания: 0
isbn: 9780007402250
Скачать книгу
had produced a photographic image of the bone structure of a human hand. As he did not know what the electric waves were, he called them ‘X-rays’.

      News of Roentgen’s amazing discovery had broken on 5 January 1896 in a Vienna newspaper, and had rapidly been telegraphed around the world. There was much chatter about the danger of X-rays to the modesty of women: wicked inventors might be able to see through their clothing. Scientific discovery was often frightening as well as exciting, and the penetrating powers of X-rays were the subject of much anxious debate, though nobody then knew about the dangers of radiation. The issue was privacy.

      The publicity William Preece had afforded Marconi very quickly drew the attention of newspapers and magazines, and when news of his ‘Marconi waves’ began to spread the public were intrigued to know if they too might threaten the privacy and decency of English ladies. After all, his magic boxes sent and received invisible signals which could apparently travel much further than Roentgen’s X-rays. Young as he was, Marconi found himself called upon to provide extensive interviews. Just three months after the Toynbee Hall lecture, in March 1897, the Strand Magazine published an article by H.J.W. Dam with the tide ‘The New Telegraphy’. It was syndicated worldwide by the enterprising American magazine McClure’s.

      Dam had been to see Marconi at his home in Westbourne Park in the hope of learning something about this young man whose discoveries were ‘more wonderful, more important and more revolutionary’ than Roentgen’s ‘new photography’. He found himself greeted by a most unusual character, who was ‘completely modest’ and made no claims at all as a scientist. This ‘tall, slender young man’, who looked at least thirty, had a ‘calm, serious manner and a grave precision of speech’ which gave the impression that he was much older than he was. Speaking in his ‘perfect’ English, he told the reporter that he had been for ten years an ‘ardent amateur student of electricity’.

      In the calm, considered manner which was to be his hallmark whenever called upon to explain his discoveries to the public, Marconi told Dam how he had found to his surprise while experimenting with electric waves on his father’s country estate outside Bologna that he could generate signals which went through or over hills. He really had no idea how they got there, but he had proved over and again that a rise in the land three quarters of a mile across was no obstacle to the transmission and reception of these electronic signals. Marconi explained that he had begun by copying the laboratory equipment of the great German physicist Heinrich Hertz, and had adapted it so that he could send Morse messages. But whereas Hertz had sent his electro-magnetic waves only a few yards, Marconi had achieved much greater distances, and he was not sure if he had, by chance, discovered a previously unknown phenomenon: a new kind of ‘wave’.

      The science Marconi was working with was not well understood. In 1865 the Scottish physicist James Clerk Maxwell had proposed that electro-magnetic forces travelled in waves. These were analogous to sound and light waves, but could not be detected by the human ear or eye. They travelled at the speed of light, but were invisible, because the eye could only detect certain wavelengths. Maxwell’s model was purely mathematical, and he left it to others to find a way of generating and measuring these waves. Hertz had been the first to achieve this, publishing his findings in 1888. He used a spark to generate the waves which he bounced back and forth in his laboratory. Crudely speaking, the size of the spark ‘gap’ determined the length of the waves, and Hertz had worked with fairly short waves. Marconi had experimented with a whole range of different spark transmitters, and had produced results which appeared to be substantially different from those of Hertz. In fact, because he believed his apparatus could produce waves that could reach parts impenetrable by those generated by Hertz, Marconi thought he might have chanced upon some new kind of electromagnetic signal. Dam asked: What is the difference between these and the Hertz waves?’

      Marconi replied: ‘I don’t know. I am not a professional scientist, but I doubt if any scientist can tell you.’ He thought it might have something to do with the form of the wave. As to the nuts and bolts of his equipment, Marconi said apologetically that he could not say more because it was being patented, and was therefore top secret. What he could tell the astonished reporter was that his waves ‘penetrate everything and are not reflected or refracted’ even by solid stone walls or metal. He could even send them through an ‘ironclad’, a heavily reinforced battleship.

      This last claim set up instant alarm in the reporter: its implications were far more serious than the possibility of X-rays compromising the modesty of ladies. ‘Could you not from this room explode a box of gunpowder placed across the street in that house yonder?’ Dam asked.

      ‘Yes,’ Marconi replied confidently. ‘If I could put two wires or two plates in the powder, I could set up an induced current which would cause a spark and explode it.’

      ‘At what distance have you exploded gunpowder by means of electric waves?’

      ‘A mile and a half.’

      Could Marconi’s instruments ignite the explosive magazine of an ironclad and blow it up from a distance? Already the Royal Navy was concerned that if its ships carried wireless telegraphy equipment, the signals might blow up their own stores of powder. It could be a problem, Marconi conceded. Beams from electric lighthouses along the coast could destroy an unwary fleet in seconds. Warming to this notion, Dam wrote: ‘Of all the coast defences ever dreamed of, the idea of exploding ironclads by electric waves from the shore and over distances equal to modern cannon ranges is certainly the most terrible possibility yet conceived.’

      Blowing up ships, however, had never been in Marconi’s mind. Quite the reverse. From boyhood, when his father had bought him a yacht which he sailed in the Bay of Genoa, he had loved the sea. Though he had no clear idea how his wireless waves would be used in practical terms, he did imagine that there was a real prospect of communications between ships and shore, and between ships on the open ocean, where there were no telegraph cables.

      In London, Marconi and his mother could have enjoyed a glamorous social round: nightly balls, dinner parties, the opera, Ascot and all the trappings of the Season. Annie had many relatives in town, and always enjoyed her trips to England. But there was to be little time for frivolous socialising: Guglielmo had succeeded beyond their wildest dreams, and he was fearful that if he did not move fast someone else would overtake him in the exploitation of the new telegraphy. After all, he was only an amateur whose invention was homespun, devised after long hours working alone in the attic of the family country home in Italy.

       2

       Silkworms and Whiskey

      The Villa Griffone is set in its own grounds of orchards, vineyards and fields in rolling countryside outside the village of Pontecchio, near Bologna. Bologna had water-powered silk-weaving mills long before the Industrial Revolution transformed British industry in the late eighteenth century. The city had a distinguished history of scientific discovery, and was the home of the eighteenth-century pioneer of electrical forces Luigi Galvani. Nearly all the advances in the study of electro-magnetism had been achieved by trial and error, in the absence of any useful theory. In fact theory had sometimes got in the way of understanding, as is often the case. Galvani, a Professor of Anatomy at the ancient University of Bologna, had come to the conclusion that frogs could produce electricity after the chance discovery that specimens he was dissecting reacted to an electrical current. His disciple, and later his opponent, Alessandro Volta showed that the frogs were merely acting as crude batteries,