Guglielmo Marconi
Guglielmo Giovanni Maria Marconi, 1st Marquis of Marconi was an Italian inventor and electrical engineer, known for his pioneering work on long-distance radio transmission, development of Marconi's law, and a radio telegraph system. He is credited as the inventor of radio, and he shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".
Marconi was also an entrepreneur, businessman, and founder of The Wireless Telegraph & Signal Company in the United Kingdom in 1897. He succeeded in making an engineering and commercial success of radio by innovating and building on the work of previous experimenters and physicists. In 1929, Marconi was ennobled as a Marchese by King Victor Emmanuel III of Italy, and, in 1931, he set up Vatican Radio for Pope Pius XI.
Biography
Early years
Marconi was born into the Italian nobility as Guglielmo Giovanni Maria Marconi in Bologna on 25 April 1874, the second son of Giuseppe Marconi and his Irish wife Annie Jameson. Marconi had a brother, Alfonso, and a stepbrother, Luigi. Between the ages of two and six, Marconi and his elder brother Alfonso lived with their mother in the English town of Bedford.Education
Marconi did not attend school as a child and did not go on to formal higher education. Instead, he learned chemistry, math, and physics at home from a series of private tutors hired by his parents. His family hired additional tutors for Guglielmo in the winter when they would leave Bologna for the warmer climate of Tuscany or Florence. Marconi noted an important mentor was professor Vincenzo Rosa, a high school physics teacher in Livorno. Rosa taught the 17-year-old Marconi the basics of physical phenomena as well as new theories on electricity. At the age of 18 and back in Bologna, Marconi became acquainted with University of Bologna physicist Augusto Righi, who had done research on Heinrich Hertz's work. Righi permitted Marconi to attend lectures at the university and also to use the University's laboratory and library.Radio work
From youth, Marconi was interested in science and electricity. In the early 1890s, he began working on the idea of "wireless telegraphy"—i.e., the transmission of telegraph messages without connecting wires as used by the electric telegraph. This was not a new idea; numerous investigators and inventors had been exploring wireless telegraph technologies and even building systems using electric conduction, electromagnetic induction and optical signalling for over 50 years, but none had proven technically and commercially successful. A relatively new development came from Heinrich Hertz, who, in 1888, demonstrated that one could produce and detect electromagnetic radiation. At the time, this radiation was commonly called "Hertzian" waves, and is now generally referred to as radio waves.There was a great deal of interest in radio waves in the physics community, but this interest was in the scientific phenomenon, not in its potential as a communication method. Physicists generally looked on radio waves as an invisible form of light that could only travel along a line of sight path, limiting its range to the visual horizon like existing forms of visual signaling. Hertz's death in 1894 brought published reviews of his earlier discoveries including a demonstration on the transmission and detection of radio waves by the British physicist Oliver Lodge and an article about Hertz's work by Augusto Righi. Righi's article renewed Marconi's interest in developing a wireless telegraphy system based on radio waves, a line of inquiry that Marconi noted other inventors did not seem to be pursuing.
Developing radio telegraphy
At the age of 20, Marconi began to conduct experiments in radio waves, building much of his own equipment in the attic of his home at the Villa Griffone in Pontecchio, Italy with the help of his butler Mignani. Marconi built on Hertz's original experiments and, at the suggestion of Righi, began using a coherer, an early detector based on the 1890 findings of French physicist Édouard Branly and used in Lodge's experiments, that changed resistance when exposed to radio waves. In the summer of 1894, he built a storm alarm made up of a battery, a coherer, and an electric bell, which went off when it picked up the radio waves generated by lightning.Late one night, in December 1894, Marconi demonstrated a radio transmitter and receiver to his mother, a set-up that made a bell ring on the other side of the room by pushing a telegraphic button on a bench. Supported by his father, Marconi continued to read through the literature and picked up on the ideas of physicists who were experimenting with radio waves. He developed devices, such as portable transmitters and receiver systems, that could work over long distances, turning what was essentially a laboratory experiment into a useful communication system. Marconi came up with a functional system with many components:
- A relatively simple oscillator or spark-producing radio transmitter;
- A wire or metal sheet capacity area suspended at a height above the ground;
- A coherer receiver, which was a modification of Édouard Branly's original device with refinements to increase sensitivity and reliability;
- A telegraph key to operate the transmitter to send short and long pulses, corresponding to the dots-and-dashes of Morse code; and
- A telegraph register activated by the coherer which recorded the received Morse code dots and dashes onto a roll of paper tape.
Transmission breakthrough
A breakthrough came in the summer of 1895, when Marconi found that much greater range could be achieved after he raised the height of his antenna and, borrowing from a technique used in wired telegraphy, grounded his transmitter and receiver. With these improvements, the system was capable of transmitting signals up to and over hills. The monopole antenna reduced the frequency of the waves compared to the dipole antennas used by Hertz, and radiated vertically polarized radio waves which could travel longer distances. By this point, he concluded that a device could become capable of spanning greater distances, with additional funding and research, and would prove valuable both commercially and militarily. Marconi's experimental apparatus proved to be the first engineering-complete, commercially successful radio transmission system.Marconi wrote to the Ministry of Post and Telegraphs, then under the direction of Pietro Lacava, explaining his wireless telegraph machine and asking for funding. He never received a response to his letter, which was eventually dismissed by the Minister, who wrote "to the Longara" on the document, referring to the insane asylum on Via della Lungara in Rome.
In 1896, Marconi spoke with his family friend Carlo Gardini, Honorary Consul at the United States Consulate in Bologna, about leaving Italy to go to Wales in the United Kingdom. Gardini wrote a letter of introduction to the Ambassador of Italy in London, Annibale Ferrero, explaining who Marconi was and about his extraordinary discoveries. In his response, Ambassador Ferrero advised them not to reveal Marconi's results until after a patent was obtained. He also encouraged Marconi to come to the United Kingdom where he believed it would be easier to find the necessary funds to convert his experiments into practical use.
Finding little interest or appreciation for his work in Italy, Marconi travelled to London in early 1896 at the age of 21, accompanied by his mother, to seek support for his work. Marconi arrived at Dover, and the Customs officer opened his case to find various apparatus. The customs officer immediately contacted the Admiralty in London. While there, Marconi gained the interest and support of William Preece, the Chief Electrical Engineer of the British Post Office. During this time Marconi decided he should patent his system, which he applied for on 2 June 1896, British Patent number 12039 titled "Improvements in Transmitting Electrical impulses and Signals, and in Apparatus therefor", which would become the first patent for a radio wave based communication system.
The British become interested
Marconi made the first demonstration of his system for the British government in July 1896. A further series of demonstrations for the British followed, and, by March 1897, Marconi had transmitted Morse code signals over a distance of about across Salisbury Plain. On 13 May 1897, Marconi sent the first ever wireless communication over open sea – a message was transmitted over Môr Hafren aka the Seven Sea from Flat Holm Island Off Cardiff Wales to Lavernock Point in Penarth also in Wales in the Vale of Glamorgan, a distance of. The message read "Are you ready". The transmitting equipment was almost immediately relocated to Brean Down Fort on the Somerset coast, stretching the range to.commemorates Marconi's first public transmission of wireless signals.
Impressed by these and other demonstrations, Preece introduced Marconi's ongoing work to the general public at two important London lectures: "Telegraphy without Wires", at the Toynbee Hall on 11 December 1896; and "Signalling through Space without Wires", given to the Royal Institution on 4 June 1897.
Numerous additional demonstrations followed, and Marconi began to receive international attention. In July 1897, he carried out a series of tests at La Spezia, in his home country, for the Italian government. A test for Lloyds between Ballycastle and Rathlin Island, Northern Ireland, was conducted on 6 July 1898. A transmission across the English channel was accomplished on 27 March 1899, from Wimereux, France to South Foreland Lighthouse, England. Marconi set up an experimental base at the Haven Hotel, Sandbanks, Poole Harbour, Dorset, where he erected a 100-foot high mast. He became friends with the van Raaltes, the owners of Brownsea Island in Poole Harbour, and his sailing boat, the Elettra, was often moored on Brownsea or at the Haven Hotel when he was not conducting experiments at sea.
In December 1898, the British lightship service authorized the establishment of wireless communication between the South Foreland lighthouse at Dover and the East Goodwin lightship, twelve miles distant. On 17 March 1899, the East Goodwin lightship sent the first SOS message, a signal on behalf of the merchant vessel Elbe which had run aground on Goodwin Sands. The message was received by the radio operator of the South Foreland lighthouse, who summoned the aid of the Ramsgate lifeboat.
In the autumn of 1899, the first demonstrations in the United States took place. Marconi had sailed to the U.S. at the invitation of the New York Herald newspaper to cover the America's Cup international yacht races off Sandy Hook, New Jersey. The transmission was done aboard the SS Ponce, a passenger ship of the Porto Rico Line. Marconi left for England on 8 November 1899 on the American Line's, and he and his assistants installed wireless equipment aboard during the voyage. On 15 November Saint Paul became the first ocean liner to report her imminent return to Great Britain by wireless when Marconi's Royal Needles Hotel radio station contacted her 66 nautical miles off the English coast.
Transatlantic transmissions
of Milan.
At the turn of the 20th century, Marconi began investigating a means to signal across the Atlantic in order to compete with the transatlantic telegraph cables. Marconi established a wireless transmitting station at Marconi House, Rosslare Strand, Co. Wexford in 1901 to act as a link between Poldhu in Cornwall, England and Clifden in Co. Galway, Ireland. He soon made the announcement that the message was received at Signal Hill in St John's, Newfoundland on 12 December 1901, using a kite-supported antenna for reception—signals transmitted by the company's new high-power station at Poldhu, Cornwall. The distance between the two points was about. It was heralded as a great scientific advance, yet there also was—and continues to be—considerable scepticism about this claim. The exact wavelength used is not known, but it is fairly reliably determined to have been in the neighbourhood of 350 meters. The tests took place at a time of day during which the entire transatlantic path was in daylight. It is now known that this was the worst possible choice. At this medium wavelength, long-distance transmission in the daytime is not possible because of heavy absorption of the skywave in the ionosphere. It was not a blind test; Marconi knew in advance to listen for a repetitive signal of three clicks, signifying the Morse code letter S. The clicks were reported to have been heard faintly and sporadically. There was no independent confirmation of the reported reception, and the transmissions were difficult to distinguish from atmospheric noise. A detailed technical review of Marconi's early transatlantic work appears in John S. Belrose's work of 1995. The Poldhu transmitter was a two-stage circuit.
for Vanity Fair, 1905
Feeling challenged by skeptics, Marconi prepared a better organised and documented test. In February 1902, the SS Philadelphia sailed west from Great Britain with Marconi aboard, carefully recording signals sent daily from the Poldhu station. The test results produced coherer-tape reception up to, and audio reception up to. The maximum distances were achieved at night, and these tests were the first to show that radio signals for medium wave and longwave transmissions travel much farther at night than in the day. During the daytime, signals had been received up to only about, less than half of the distance claimed earlier at Newfoundland, where the transmissions had also taken place during the day. Because of this, Marconi had not fully confirmed the Newfoundland claims, although he did prove that radio signals could be sent for hundreds of kilometres, despite some scientists' belief that they were limited essentially to line-of-sight distances.
On 17 December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada became the world's first radio message to cross the Atlantic from North America. In 1901, Marconi built a station near South Wellfleet, Massachusetts that sent a message of greetings on 18 January 1903 from United States President Theodore Roosevelt to King Edward VII of the United Kingdom. However, consistent transatlantic signalling was difficult to establish.
Marconi began to build high-powered stations on both sides of the Atlantic to communicate with ships at sea, in competition with other inventors. In 1904, he established a commercial service to transmit nightly news summaries to subscribing ships, which could incorporate them into their on-board newspapers. A regular transatlantic radio-telegraph service was finally begun on 17 October 1907 between Clifden, Ireland and Glace Bay, but even after this the company struggled for many years to provide reliable communication to others.
''Titanic''
The role played by Marconi Co. wireless in maritime rescues raised public awareness of the value of radio and brought fame to Marconi, particularly the sinking of the RMS Titanic on 15 April 1912 and the RMS Lusitania on 7 May 1915.RMS Titanic radio operators Jack Phillips and Harold Bride were not employed by the White Star Line but by the Marconi International Marine Communication Company. After the sinking of the ocean liner on 15 April 1912, survivors were rescued by the RMS Carpathia of the Cunard Line. Also employed by the Marconi Company was David Sarnoff, who later headed RCA. Wireless communications were reportedly maintained for 72 hours between Carpathia and Sarnoff, but Sarnoff's involvement has been questioned by some modern historians. When Carpathia docked in New York, Marconi went aboard with a reporter from The New York Times to talk with Bride, the surviving operator.
On 18 June 1912, Marconi gave evidence to the Court of Inquiry into the loss of Titanic regarding the marine telegraphy's functions and the procedures for emergencies at sea. Britain's postmaster-general summed up, referring to the Titanic disaster: "Those who have been saved, have been saved through one man, Mr. Marconi... and his marvellous invention." Marconi was offered free passage on Titanic before she sank, but had taken Lusitania three days earlier. As his daughter Degna later explained, he had paperwork to do and preferred the public stenographer aboard that vessel.
Continuing work
Over the years, the Marconi companies gained a reputation for being technically conservative, in particular by continuing to use inefficient spark-transmitter technology, which could be used only for radio-telegraph operations, long after it was apparent that the future of radio communication lay with continuous-wave transmissions which were more efficient and could be used for audio transmissions. Somewhat belatedly, the company did begin significant work with continuous-wave equipment beginning in 1915, after the introduction of the oscillating vacuum tube. The New Street Works factory in Chelmsford was the location for the first entertainment radio broadcasts in the United Kingdom in 1920, employing a vacuum tube transmitter and featuring Dame Nellie Melba. In 1922, regular entertainment broadcasts commenced from the Marconi Research Centre at Great Baddow, forming the prelude to the BBC, and he spoke of the close association of aviation and wireless telephony in that same year at a private gathering with Florence Tyzack Parbury, and even spoke of interplanetary wireless communication.Later years and Fascism
In 1914, Marconi was made a Senator in the Senate of the Kingdom of Italy and appointed Honorary Knight Grand Cross of the Royal Victorian Order in the UK. During World War I, Italy joined the Allied side of the conflict, and Marconi was placed in charge of the Italian military's radio service. He attained the rank of lieutenant in the Royal Italian Army and of commander in the Regia Marina. In 1929, he was made a marquess by King Victor Emmanuel III.
Marconi joined the Italian Fascist party in 1923. In 1930, Italian dictator Benito Mussolini appointed him President of the Royal Academy of Italy, which made Marconi a member of the Fascist Grand Council.
While helping to develop microwave technology, Marconi suffered nine heart attacks in the span of 3 years preceding his death. Marconi died in Rome on 20 July 1937 at age 63, following the ninth, fatal, heart attack, and Italy held a state funeral for him. As a tribute, shops on the street where he lived were "Closed for national mourning". In addition, at 6 pm the next day, the time designated for the funeral, all BBC transmitters and wireless Post Office transmitters in the British Isles observed two minutes of silence in his honour. The British Post Office also sent a message requesting that all broadcasting ships honour Marconi with two minutes of broadcasting silence as well. His remains are housed in the Villa Griffone at Sasso Marconi, Emilia-Romagna, which assumed that name in his honour in 1938.
In 1943, Marconi's elegant sailing yacht, the Elettra, was commandeered and re-fitted as a warship by the German Navy. She was sunk by the RAF on 22 January 1944. After the war, the Italian Government tried to retrieve the wreckage, to rebuild the boat, and the wreckage was removed to Italy. Eventually, the idea was abandoned, and the wreckage was cut into pieces which were distributed amongst Italian museums.
In 1943, the Supreme Court of the United States handed down a decision on Marconi's radio patents restoring some of the prior patents of Oliver Lodge, John Stone Stone, and Nikola Tesla. The decision was not about Marconi's original radio patents and the court declared that their decision had no bearing on Marconi's claim as the first to achieve radio transmission, just that since Marconi's claim to certain patents was questionable, he could not claim infringement on those same patents. There are claims the high court was trying to nullify a World War I claim against the United States government by the Marconi Company via simply restoring the non-Marconi prior patent.
Personal life
Marconi was a friend of Charles van Raalte and his wife Florence, the owners of Brownsea Island; and of Margherita, their daughter, and in 1904 he met her friend, Beatrice O'Brien, a daughter of The 14th Baron Inchiquin. On 16 March 1905, Beatrice O'Brien and Marconi were married, and spent their honeymoon on Brownsea Island. They had three daughters, Degna, Gioia, and Lucia, and a son, Giulio, 2nd Marchese Marconi. In 1913, the Marconis returned to Italy and became part of Rome society. Beatrice served as a lady-in-waiting to Queen Elena. At Marconi's request, his marriage to Beatrice was annulled on 27 April 1927, so he could remarry. Marconi and Beatrice had divorced on 12 February 1924 in the free city of Fiume.Marconi went on to marry Maria Cristina Bezzi-Scali, the only daughter of Francesco, Count Bezzi-Scali. To do this he had to be confirmed in the Catholic faith and became a devout member of the Church. He was baptised Catholic but had been brought up as a member of the Anglican Church. On 12 June 1927 Marconi married Maria Cristina in a civil service, with a religious ceremony performed on 15 June. Marconi was 53 years old and his second wife, Maria Cristina Bezzi-Scali, was 26 years old, just under half her new husband's age. They had one daughter, Maria Elettra Elena Anna, who married Prince Carlo Giovannelli in 1966; they later divorced. For unexplained reasons, Marconi left his entire fortune to his second wife and their only child, and nothing to the children of his first marriage.
Later in life, Marconi was an active Italian Fascist and an apologist for their ideology and actions such as the attack by Italian forces in Ethiopia.
In his lecture he stated: "I reclaim the honor of being the first fascist in the field of radiotelegraphy, the first who acknowledged the utility of joining the electric rays in a bundle, as Mussolini was the first in the political field who acknowledged the necessity of merging all the healthy energies of the country into a bundle, for the greater greatness of Italy".
Marconi wanted to personally introduce in 1931 the first radio broadcast of a Pope, Pius XI, and did announce at the microphone: "With the help of God, who places so many mysterious forces of nature at man's disposal, I have been able to prepare this instrument which will give to the faithful of the entire world the joy of listening to the voice of the Holy Father".
Legacy and honours
Honours and awards
- In 1902 he was appointed a Grand Officer of the Order of the Crown of Italy
- In 1909, Marconi shared the Nobel Prize in Physics with Karl Braun for his contributions to radio communications.
- In 1914 named senator by the king of Italy Vittorio Emanuele III
- In 1918, he was awarded the Franklin Institute's Franklin Medal.
- In 1920, he was awarded the IRE Medal of Honor, now the IEEE Medal of Honor.
- In 1929, he was made a marquess by King Victor Emmanuel III, thus becoming Marchese Marconi.
- In 1931, he was awarded with John Scott Medal by wireless telegraphy
- In 1933, he was awarded Order of the Rising Sun.
- In 1934, he was awarded the Wilhelm Exner Medal.
- In 1975, Marconi was inducted into the National Inventors Hall of Fame.
- In 1977, Marconi was inducted into the National Broadcasters Hall of Fame.
- In 1988, the Radio Hall of Fame inducted Marconi as a Pioneer.
- In 1990, the Bank of Italy issued a 2,000 lire banknote featuring his portrait on the front and on the back his accomplishments.
- In 2001, Great Britain released a commemorative British two pound coin celebrating the 100th anniversary of Marconi's first wireless communication.
- Marconi's early experiments in wireless telegraphy were the subject of two IEEE Milestones; one in Switzerland in 2003 and most recently in Italy in 2011.
- In 2009, Italy issued a commemorative silver €5 coin honouring the centennial of Marconi's Nobel Prize.
- In 2009, he was inducted into the New Jersey Hall of Fame.
- The Dutch radio academy bestows the Marconi Awards annually for outstanding radio programmes, presenters and stations.
- The National Association of Broadcasters bestows the annual NAB Marconi Radio Awards also for outstanding radio programs and stations.
Tributes
- A funerary monument to the effigy of Marconi can be seen in the Basilica of Santa Croce, Florence but his remains are in near the Mausoleum of Guglielmo Marconi in Pontecchio Marconi, near Bologna. His former villa, adjacent to the mausoleum is the Marconi Museum with much of his equipment.
- A statue of Guglielmo Marconi stands in Church Square Park in Hoboken, NJ.
- A Guglielmo Marconi sculpture by Attilio Piccirilli stands in Washington, D.C.
- A large collection of Marconi artefacts was held by The General Electric Company, p.l.c. of the United Kingdom which later renamed itself Marconi plc and Marconi Corporation plc. In December 2004 the extensive Marconi Collection, held at the former Marconi Research Centre at Great Baddow, Chelmsford, Essex UK was donated to the nation by the Company via the University of Oxford. This consisted of the BAFTA award-winning MarconiCalling website, some 250+ physical artefacts and the massive ephemera collection of papers, books, patents and many other items. The artefacts are now held by The Museum of the History of Science and the ephemera Archives by the nearby Bodleian Library. Following three years' work at the Bodleian, an Online Catalogue to the Marconi Archives was released in November 2008.
- A granite obelisk stands on the cliff top near the site of Marconi's Marconi's Poldhu Wireless Station in Cornwall, commemorating the first transatlantic transmission.
- An urban park square named in 1937 located Philadelphia, Pennsylvania at Oregon Ave and South Broad Street, including later in 1975 a bronze statue erected of Marconi on the east side of Marconi Plaza Park.
Places and organisations named after Marconi
Outer space
The asteroid 1332 Marconia is named in his honour. A large crater on the far side of the moon is also named after him.Europe
Italy
- Bologna Guglielmo Marconi Airport, of Bologna, is named after Marconi, its native son.
- Open University Guglielmo Marconi in Rome, Italy
- Ponte Guglielmo Marconi, bridge that connects Piazza Augusto Righi with Piazza Tommaso Edison, in Rome
- Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", Università di Bologna
Sweden
- The street Marconigatan in Frölunda in Gothenburg.
Oceania
Australia
- Australian football and social club Marconi Stallions.
North America
Canada
- The 'Marconi's Wireless Telegraph Company of Canada' in 2001.
- The Marconi National Historic Sites of Canada was created by Parks Canada as a tribute to Marconi's vision in the development of radio telecommunications. The first official wireless message was sent from this location by the Atlantic Ocean to England in 1902. The museum site is located in Glace Bay, Nova Scotia, at Table Head on Timmerman Street.
United States
California
- Marconi Conference Center and State Historic Park, site of the transoceanic Marshall Receiving Station, Marshall.
Hawaii
- Marconi Wireless Telegraphy Station on Oahu's North Shore, briefly the world's most powerful telegraph station.
Massachusetts
- Marconi Beach in Wellfleet, Massachusetts, part of the Cape Cod National Seashore, located near the site of his first transatlantic wireless signal from the United States to Britain. There are still remnants of the wireless tower at this beach and at Forest Road Beach in Chatham, Massachusetts.
New Jersey
- New Brunswick Marconi Station, now the Guglielmo Marconi Memorial Plaza in Somerset, NJ. President Woodrow Wilson's Fourteen Points speech was transmitted from the site in 1918.
- Belmar Marconi Station, now the InfoAge Science History Center in Wall Township, NJ.
New York
- La Scuola d'Italia Guglielmo Marconi on New York City's Upper East Side.
Pennsylvania
- Marconi Plaza, Philadelphia, Pennsylvania. Roman terrace-styled plaza originally designed by the architects Olmsted Brothers in 1914–1916, built as the grand entrance for the 1926 Sesquicentennial Exposition and renamed to honor Marconi.
Patents
British patents
- "Improvements in Transmitting Electrical impulses and Signals, and in Apparatus therefor". Date of Application 2 June 1896; Complete Specification Left, 2 March 1897; Accepted, 2 July 1897.
- "Improvements in Apparatus for Wireless Telegraphy". Date of Application 26 April 1900; Complete Specification Left, 25 February 1901; Accepted, 13 April 1901.
- British patent No. 5113 "Improvements in Transmitters suitable for Wireless Telegraphy". Date of Application 1 March 1904; Complete Specification Left, 30 November 1904; Accepted, 19 January August 1905.
- British patent No. 21640 "Improvements in Apparatus for Wireless Telegraphy". Date of Application 8 October 1904; Complete Specification Left, 6 July 1905; Accepted, 10 August 1905.
- British patent No. 14788 "Improvements in or relating to Wireless Telegraphy". Date of Application 18 July 1905; Complete Specification Left, 23 January 1906; Accepted, 10 May 1906.
US patents
- "Transmitting electrical signals", filed December 1896, patented July 1897
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Apparatus employed in wireless telegraphy".
- "Receiver for electrical oscillations".
- "Apparatus for wireless telegraphy"
- "Wireless telegraphy system". Filed 19 November 1901; Issued 19 April 1904.
- "Wireless signaling system". Filed 10 September 1903; Issued 24 May 1904.
- "Apparatus for wireless telegraphy"
- "Wireless telegraphy". Filed 13 October 1903
- "Wireless telegraphy". Filed 13 October 1903; Issued 13 June 1905.
- "Wireless telegraphy". Filed 28 November 1902; Issued 14 April 1908.
- "Wireless telegraphy".
- "Detecting electrical oscillations". Filed 2 February 1903; Issued 14 April 1908.
- "Wireless telegraphy". Filed 2 February 1903; Issued 14 April 1908.
- "Wireless signaling system". Filed 9 August 1906; Issued 8 June 1909.
- "Transmitting apparatus for wireless telegraphy". Filed 10 April 1908; Issued 28 September 1909.
- "Apparatus for wireless telegraphy".
- "Apparatus for wireless telegraphy". Filed 10 April 1908; Issued 28 September 1909.
- "Apparatus for wireless telegraphy". Filed 31 March 1909; Issued 12 April 1910.
- "Transmitting apparatus for wireless telegraphy". Filed 15 July 1910; Issued 11 July 1911.
- "Means for generating alternating electric currents". Filed 27 January 1914; Issued 7 July 1914.
- "Transmitting apparatus for use in wireless telegraphy and telephony". Filed 31 December 1913; Issued 15 May 1917.
- "Wireless telegraph transmitter".
- "Electric accumulator". Filed 9 March 1918
- "Transmitter for wireless telegraphy". Filed 20 July 1908; Issued 3 August 1915.
- "Thermionic valve". Filed 14 October 1926; Issued 20 November 1934.
Reissued (US)
- "Transmitting electrical impulses and signals and in apparatus, there-for". Filed 1 April 1901; Issued 4 June 1901.