[BITList] Ruler of the waves

[John Feltham]

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Marconi,  Guglielmo  (1874-1937), physicist and inventor of wireless transmission, was born on 25 April 1874 in Bologna, Italy, the son of Giuseppe Marconi (1826-1904), a local administrator and landowner, and his second wife, Annie (b. c.1843), daughter of Andrew Jameson of the notable Irish family of whiskey distillers. Owing to his poor health Marconi was educated by private tutors. During his one year at the private Istituto Cavallero in Florence he developed a lifelong friendship with the young Marchese Luigi Solari, later one of his most important collaborators. At Leghorn in 1891 he attended the physics lectures given by Professor Giotto Bizzarini at the technical institute, and concurrently took private instruction in physics from Professor Vincenzo Rosa, and learned the Morse code and techniques of transmission.

Education in physics

Marconi's health improved in the maritime climate of Leghorn, and, under his mother's influence, he was more fluent in English than Italian. His understanding of physics improved by reading technical articles about electricity, many of these having been sent from Britain by his relatives, and also by reading the biography of Benjamin Franklin. Contact with Rosa was interrupted when Rosa was transferred to Alessandria, in Piedmont, but resumed during the summer of 1894 when they were on holiday in the same area. This gave them the opportunity to discuss Oliver Lodge's recent publications on Hertz's experiments on electrical waves. Marconi's knowledge in that field had by then been augmented through his attendance at the laboratory of the well-known physicist Professor Augusto Righi of Bologna University. Righi's experiments, like those of Hertz, were concerned with Maxwell's electromagnetic theory of light (1873). Righi confirmed and extended Maxwell's theory, which was not yet accepted by physicists, including William Thomson, formerly Maxwell's adviser and correspondent. In Righi's laboratory Marconi had the opportunity to familiarize himself with Hertz's oscillators and resonators, including those for short waves and microwaves which Righi had improved, and to read Righi's numerous articles on this topic. At this time Hertz and Righi intended only to confirm Maxwell's theory; there is no proof that Righi was interested in signal transmission by means of Hertzian waves. It was Marconi who first had the idea of employing this apparatus to develop a practical and useful system of wireless telegraphy. It is clear that by the end of 1894 he had a thorough grasp of the physical background, and a practical and conceptual understanding of electricity which surpassed that of a student and had matured to that of an expert.

First patent for wireless transmission

During the winter of 1894 Marconi devoted himself to improving oscillators (as transmitters) and resonators (as receivers) and every part of a practical system of telegraphy without wires. In the spring of 1895, following experiments over shorter ranges, he arranged to transmit signals from his laboratory to a barn 1.5 km distant and hidden from sight behind a hill. He then sought to interest the Italian government, but received only the advice to apply for a patent. Having decided to leave Italy, and helped by his mother's cousin, the engineer Henry Jameson Davies, he arrived in England on 2 February 1896 with his apparatus. A letter of recommendation from the electrical engineer A. A. Campbell Swinton gained him the confidence and assistance of Sir William Henry Preece, chief engineer of the Post Office, who himself had previously succeeded in transmitting electromagnetic signals by the inductive method. After several demonstrations, including that of 27 July when signals were sent across 300 metres from the roof of the General Post Office at St Martins-le-Grand to a bank in Queen Victoria Street, Marconi succeeded in the more difficult task of transmitting over 14 km on Salisbury Plain. British army and navy experts were present at these demonstrations, which received good coverage in the newspapers.

Over the same period Marconi worked hard to prepare his patent specification. He withdrew his first application, filed in March 1896, substituting a new specification on 2 June. This, the first British patent for wireless telegraphy, was granted on 2 July 1896 as no. 12,039: 'Improvements in transmitting electrical impulses and signals and in apparatus thereof'. On 13 July an American patent was granted for the same specification. These patents are noteworthy for the drawings of his apparatus, clearly showing his apparatus with aerial antenna and earth, and in particular for the detailed information on his receiver (the coherer). To some extent it resembled those of Calzecchi-Onesti, Branly, and Lodge, but it was smaller and its improvements made it more reliable. Every part of Marconi's apparatus had been thoroughly tested, in the laboratory and out of doors, over longer ranges. In May 1897 signals sent the 15 km across the Bristol Channel were observed by the famous German scientist Professor A. Slaby. The Italian navy then showed interest and in July Marconi organized transmissions from the arsenal at La Spezia to various islands at up to 7 km distant, and then to the battleship San Martino 18 km out at sea.

Publicity and further advances

After returning to England, Marconi established, on 20 July 1897, the Wireless Signal and Telegraph Company, and in 1900 Marconi's Wireless Telegraph Ltd. During July and August he transmitted messages between Queen Victoria's residence at Osborne House on the Isle of Wight and the royal yacht, Osborne, carrying information about her son the prince of Wales. This service was much appreciated by the queen and was of course an invaluable advertisement for Marconi's company. Hoping to extend the transmission distances by the use of long waves and very high antennas, Marconi successfully transmitted from the Needles on the Isle of Wight to a ship 30 km out at sea, and then over the 50 km between Salisbury and Bath. The importance of these transmissions lay in their reception at locations below the horizon. Marconi also made experiments to syntonize the signals (that is, to tune them accurately), perhaps aware that Lodge had filed a patent for syntonic wireless telegraphy the previous year. On 27 March 1899, using aerials about 54 metres high, he transmitted Morse code signals across the English Channel from South Foreland to Wimereux, some 50 km. That same year Marconi followed the America's Cup regatta, sending about 1200 messages from the liner Ponce to inform the United States public of the challenges between the American Columbia II (the eventual winner) and the English Shamrock. It was his great opportunity to spread a wider understanding of the importance of wireless telegraphy for peaceful purposes. During this period, he established an American wireless telegraphy company on the lines of the existing British company.

Some technical aspects remained to be improved: to avoid interference between several transmissions and to preserve the secrecy of messages, Marconi developed, and in 1900 patented in the UK and USA, a syntonic system, which made it possible to send signals simultaneously from several stations without interference, using different wavelengths and appropriate induction coils. The principal was to have the same LC product (where L was the induction and C the capacity) in both primary and secondary circuits. With this system it was possible to have partial privacy and transmission distances up to 300 km out to sea. This experiment was of key importance in achieving confidence in the transatlantic transmission which Marconi intended to organize within a few months. This patent, however, was contested by Lodge and Braun. Their own patents were subsequently acquired by Marconi's company.

First transatlantic transmission

When, in 1901, Marconi announced his proposals for a transatlantic transmission some scientists were outraged at the news, believing that electromagnetic waves, like optical waves, must travel along straight paths and that it was impossible to send messages beyond such large visible barriers as the curvature of the earth which would intervene between the two sides of the Atlantic Ocean. They supposed that Marconi did not understand the laws of physics and mathematics. The great French physicist Henri Poincare declared that electromagnetic waves would fade within 300 km. Marconi, however, relied on his earlier trials, where he had already sent signals to receivers beyond the horizon, and confidently organized a transmission from Poldhu in Cornwall to Signal Hill in Newfoundland, about 3400 km. There were many difficulties to overcome in England and the USA, and in Canada severe storms destroyed his very tall antennas, obliging him to resort to a kite-borne antenna raised to about 180 metres. But on 12 December 1901 Marconi received the signal consisting of three dots of Morse code-the letter S. The transmission had been a success. Overnight Marconi became a household name. He was just twenty-seven years old.

Over the following years, while overcoming the initial deficiencies of his system and developing the technology needed for its practical use, Marconi battled with the telegraph cable companies and struggled against those who claimed priority for inventing wireless telegraphy, meanwhile continuing to develop the technology for its practical use. As the coherer did not function well on a rolling ship, Marconi substituted the magnetic detector as a more reliable receiver, first using rotating magnets, and then fixed magnets. His detector, patented in 1902, was perhaps inspired by Ernest Rutherford's article on this subject, published in 1896. From June to September 1902 Marconi, his friend and collaborator Solari, and their technician undertook experiments on board the Italian navy's royal battle cruiser Carlo Alberto during her cruise from Naples to Kronstadt and back through the Kiel Canal via Portsmouth and Gibraltar to La Spezia. During these experiments they discovered the negative effect of solar light on transmission, confirmed that signals could be transmitted beyond the high mountains of continental Europe without any negative effect on the reception of electromagnetic waves, and tried various prototypes of the magnetic detector.

Marconi was undoubtedly helped by the skilful technicians, engineers, and assistants, all knowledgeable about electricity, whom he recruited to his company. It was his great merit to bring together a scientific team, headed by J. A. Fleming, who had been Maxwell's pupil, was a consultant to Edison, and was professor of electrical technology at University College, London. Fleming was the inventor in 1904 of the thermionic valve (the diode) which, in the following years and with the De Forest triode of 1907, became so important for radio transmission. Marconi organized his team effectively and appreciated their qualities; in turn most of them regarded him with veneration.

The multiple spark generator introduced in 1904 and the rotating disc generator of 1905 resulted from Marconi's efforts to avoid the Rumkorff induction coils and the oscillators of Hertz and Righi with their high resistance which was responsible for wave attenuation. Also in 1905 Marconi developed his horizontal directional aerial, later especially for use with short waves. In the same year he married, in London, Beatrice O'Brien (b. 1882), daughter of Edward Donough O'Brien, fourteenth baron of Inchiquin, whose family had been kings of Ireland until the sixteenth century. There were two daughters and a son from this marriage. In 1909 Marconi shared the Nobel prize for physics with Ferdinand Braun, inventor of the cathode ray oscillator.

When the Italian war against the Turkish empire began in October 1911 Marconi was called in to assist the Italian army and navy, as a civil consultant, to connect the military forces on land and sea. He developed portable radio sets, and organized trench stations and aircraft transmitting systems. In November, with Solari's help, he opened powerful radio transmitting stations at Coltrano, near Pisa, inside the royal estate of San Rossore, to provide a military link to those in Tobruk and Darnah. In 1912 he developed a timed spark system to generate continuous waves, which were then modulated for signal transmission.

In 1912, during these military endeavours, Marconi was seen as a benefactor of humanity following the transmission of an SOS message that led to the rescue of about 700 of the 2300 people on board the stricken SS Titanic. Hot on the heels of this praise the Marconi scandal blew up. It began with rumours of certain assistance given to Marconi's company by British government ministers who were shareholders in the company. Journalists publicized the fact that these ministers would benefit financially if Marconi's company secured the passage into law of a bill setting up the British Imperial Wireless Network. Asquith's government was almost brought down, but although Marconi suffered some trouble, in the end his merits were recognized and he received an honorary GCVO in 1914.

Short-wave transmission

In 1913-14 Marconi investigated the use of the new thermionic valves as transmitters, bearing in mind Meissner's existing patent. Developing electronic tubes as transmitters, he created the M-round transmitter. At the start of the First World War he enlisted in the Italian army and was transferred to the navy, during which time he introduced short-wave beam systems for military use in sending secret messages and to economize on the energy needed for long-distance transmissions. He introduced more advanced radio range beacons, ground radio beacons, and radiogoniometers. These researches continued in peacetime and the results transformed and enhanced long-distance wireless communication. This was a bold step: about twenty years later the move to enormous radio stations with high and very costly antennas reversed the line of research, developing short-wave technology to improve reliability of communication. Speaking in Rome in 1928 he admitted having made a mistake in working with long waves, and that henceforth he would work with short waves. As usual, his company and other technicians followed his lead.

In his post-war short-wave experiments Marconi was helped by an outstanding new laboratory that he acquired in February 1919, namely the steam yacht Rowenska, previously owned by the archdukes of Austria. Renamed Elettra, it became his home, laboratory, and mobile receiving station. The Italian poet Gabriele D'Annunzio lauded it as 'la candida nave che naviga nel miracolo e anima i silenti aerei' ('the miraculous snow-white ship which gives life to the ethereal silence'). In 1919 Marconi attended the Versailles peace conference in Paris as the Italian government's plenipotentiary delegate. From the beginning of 1920, after several trials, broadcast transmissions were begun from Elettra, stationed in the Atlantic about 48 km from Lisbon, to Monsanto, near Lisbon, where Solari was listening to a loudspeaker connected to the receiver.

In a speech given on 20 June 1922 at the Institute of Radio Engineers in New York, Marconi described how electromagnetic waves could be reflected by conductive bodies, thereby predicting the possibility of receiving information about other ships or objects along a route although there was no direct line of sight. It was the germ of a radar detection system. In 1923 his wife sought an annulment, which was granted the following year. A few years later, in June 1927, Marconi married Maria Cristina Bezzi-Scali, a young woman of noble birth and member of an ancient and extremely well-connected family. They had one daughter, named Elettra. In the same year, on behalf of the British government, he established a radio telegraph network spanning the empire. Honorary degrees and many other marks of distinction were conferred on him from all over the world. The Italian government bestowed a marquessate on him in 1929 and the same year he became the founder president of the CNR (Italian Research Council), and the following year president of the Italian Academy. Marconi was a great propagandist for his own discoveries, thanks to the fame of his international experiments. He both had and made use of his sense of theatre. He was fond of music, a passion perhaps inherited from a musical mother.

During his last years Marconi was involved in several important experiments concerning microwaves, and is remembered for an official demonstration on 30 July 1934, carried out between S. Margherita Ligure and Sestri Levante, in which he demonstrated a radio-beam microwave (60 cm) technique enabling a ship to be steered blind, without compass or any exterior visibility, relying on an instrument to detect the silent zone produced by the interference of microwaves. Of greater military consequence were his further experiments on reflections from objects. According to A. Landini, one of his technicians, he made experiments near Civitavecchia to see if, with 50 cm microwaves, he could detect the movements of his car-another step along the way to radar detection. A great many fantastic discoveries were attributed to Marconi. Some, like the inevitable 'death rays', were mere journalistic fancy; it was true, however, that Marconi had for many years been exploring the possibility of extracting gold from seawater, of transmitting electrical energy over distance, of improving the yield of harvests, and of eliminating bacteria, all by the use of electromagnetic waves. Marconi died at his home, via Condotti 11, Rome, on 20 July 1937, following a series of heart attacks brought on by a form of angina pectoris which had afflicted him for several years.

Assessment

Marconi's character was summed up by Professor Quirino Majorana, professor of physics at Bologna University:

Guglielmo Marconi was not satisfied with his first success, which would have been sufficient to assure him perpetual celebrity; he always led the way in improving his already outstanding system. Thus it was for the syntonic problem, long-distance transmissions, directional transmissions, radiogoniometry, beam-system signalling and, more recently, the matter of short-waves and microwaves. (Q. Majorana, 1932)
No more appropriate, clear and accurate description of Marconi could have been given. The entire world was his experimental laboratory, and he persevered with confidence in the experimental method, though he often struggled against the 'official' scientific opinion. This capability distinguishes him from the numerous other pretenders to the title of inventor of wireless telegraphy.

Giorgio Dragoni 

Sources  D. E. Ravalico, Marconi giovane (1966) + M. C. Marconi, Mio marito Guglielmo (1995) + A. Colombini, La vita di Guglielmo Marconi (1974) + D. Marconi Paresce, Marconi mio padre (1993) + O. E. Dunlap, Marconi, the man and his wireless (1937) + W. K. Gesses, Guglielmo Marconi, 1874-1937 (1974) + W. P. Jolly, 'Marconi: a biography', Nature, 140 (1937) + W. J. Baker, A history of the Marconi Company (1970) + A. Righi, 'I rapporti fra Marconi e Righi', Ingeneri, Architetti, Construttori, 25 (1970), 360-61 + A. Righi, 'Giornale di Fisica', no. 4 (1974) + R. Poli, L'opera technico-scientifico di Guglielmo Marconi (1985) + G. Tabarroni, R. De Benedetti, and G. Masini, Marconi: cento anni dalla nascita (Turin, 1974) + B. Cavalieri Ducati, Guglielmo Marconi, la vita e l'ultima visita a Bologna nel 1934 (1995) + G. Paoloni, F. Monteleone, and M. G. Ianiello, eds., Cento anni di radio: da Marconi al futuro delle telecomunicazioni (Venice, 1995) + G. Pancaldi, ed., Radio da Marconi alla musica delle stelle: from Marconi to the music of the universe (1995) + P. Poli, Conosciamo veramente Guglielmo Marconi? (1979) + P. Poli, ed., Radiocommunicazioni a grande e a grandissmima distanza: celebrazione nazionale del centenario della nascita di Guglielmo Marconi (1976) + G. di Benedetto, Bibliografia Marconiana (1974) + CGPLA Eng. & Wales (1938)
Archives GEC Marconi Archives, Chelmsford + Inst. ET, Preece corresp., SC MSS 22/62-69, 122-176 FILM BFINA, actuality footage; documentary footage; news footage
Likenesses  photograph, 1896, Hult. Arch. [see illus.] · F. S. Baden-Powell, drawing, silhouette, 1900, NPG · H. Furniss, pen-and-ink drawing, NPG · A. P. F. Ritchie, cigarette card, NPG
Wealth at death  £48,529 4s. 1d.-in England: administration with will, 16 March 1938, CGPLA Eng. & Wales




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