William Gilbert was a pioneer of the experimental method and the first to explain the magnetic compass. In 1600, Gilbert published his great study of magnetism, De Magnete – "On the Magnet", in six volumes. He described the legends and scientific facts associated with magnets, lodestones, amber, and other materials that have the mysterious natural ability to attract or repel. Gilbert gave the first rational explanation of the puzzling ability of the compass needle to point north-south: the Earth itself is magnetic.
Also called magnetite, lodestone is a magnetic oxide of iron (Fe3O4) which was mined in the province of Magnesia in Thessaly (central Greece) from where the magnet gets its name.
De Magnete – the first ever book about experimental physics, and arguably the first ever scientific text – opened the era of modern physics and astronomy and started a century marked by the great achievements of Galileo, Kepler, Newton and others. The book is similar to a modern PhD thesis in layout, starting with a survey of previous work, moving on to experimental results, discussing these and setting them in the broader context of worldwide results, and ending with speculation and unsolved problems.
Title PageAnno MDC 1600 edition |
Title PageAnno MDCXXVIII 1628 edition |
Title PageAnno MDCXXXIII 1633 edition |
For a larger view, click on an image
Gilbert makes a clear distinction between the
attractive properties of magnets and rubbed amber: "for it pleases us
to call that an electric force".
Amber is called elektron in Greek, and electrum in Latin, so Gilbert decided to refer to the phenomenon by the adjective electricus and the noun electricitas, giving rise to the modern terms "electric" and "electricity". He was also the first person to use the terms "electric force," "magnetic pole," and "electric attraction". Gilbert was also court physician to Queen Elizabeth I of England, and briefly to James VI/I. De Magnete has never been out of print; an English translation in paperback is now listed for sale by Amazon.com.
Image of page 155, De Magnete (original edition) University of Glasgow
William Gilbert by BBC
William Gilbert: forgotten genius by Physics World
William Gilbert by Encyclopedia Britannica 1911
William Gilbert by Mary Bellis
William Gilbert by Russell Naughton
William Gilbert by Pierre Roberge
William Gilbert by Wikipedia
De Magnete by Wikipedia
(1) The Great Magnet, the Earth by David Stern
Commemorating the 400th anniversary of De Magnete by William Gilbert
(2) The Great Magnet, the Earth by David Stern (website hosted by NASA)
"On the Magnet" by William Gilbert of Colchester review by David Stern
"On the Magnet" by William Gilbert
reviewed in May 2000 by Stuart Malin and David Barraclough
Four hundred years might seem an excessively
long time for the production of a book review, even by slow-reading
reviewers, but there are reasons why a prompt review would have been
difficult... It is constantly necessary to remind oneself while reading
De Magnete of just how early it is. Here is science, based on
experiment and observation rather than hearsay...
The full title of Gilbert's book is: De Magnete, magneticisque coporibus, et de magno magnete tellure; Physiologia nova, plurimis et argumentis, et experimentis demonstrata. Note the last two words of the title, "experimental demonstrations", which has a very modern sound.
Click on the image for a full size view
...as the electric matter... operation is so secret, so rapid, and at times so tremendous; as it is so easily excited or put into action by friction, by heating and cooling, and perhaps by means we are totally unacquainted with; I think we may safely conclude, that electricity, as it is one of the most powerful, is also one of the most important, agents in nature. Many useful discoveries have been made respecting the action, influence, and effects of this subtle fluid; but certainly much remains to be done, and the field for future labourers [investigators] seems daily to enlarge. Indeed, notwithstanding the number of discoveries in electricity this age may justly boast of, I cannot but be of the opinion (which I mention as an incitement to the study) that, compared with the facts still undiscovered in that branch of philosophy [science], they bear but a very small proportion.
Experiments and Observations in Electricity, January 1777
by William Henly (?-1779) F.R.S. (Fellow of the Royal Society)
Philosophical Transactions of the Royal Society v67 Dec 1777, pages 97-98
http://www.bodley.ox.ac.uk/cgi-bin/ilej/image1.pl?item=page&seq=1&size=1&id=pt.1777.x.x.67.x.97
London, England
Internet Library of Early Journals
An eLib (Electronic Libraries Programme) Project by the Universities of Birmingham, Leeds, Manchester and Oxford, England
In 1800, after six years of experimenting with
chemicals in an effort to produce electric current, Alessandro Giuseppe
Volta asembled a device that was able to produce a large continuous
flow of electricity. He placed side-by-side several cups filled
with a salt solution, and then connected them with special strips of
metal that were copper at one end and tin or zinc at the other
end. Volta described his invention in a communication of
20 March 1800, to Sir Joseph Banks, President of the
Royal Society of London.
This was a revolution in electrical technology. It had
been known from very early times that a piece of amber, when rubbed,
acquired the ability to attract small pieces of paper or straw.
This curious behaviour was considered to be of no practical
significance, even after William Gilbert collected various scattered
observations and, adding many of his own, laid the foundations of
electricity in his great book De Magnete published in
1600. All through the 1600s and 1700s, static electricity
was well-known and the subject of many casual experiments, and some
serious investigation, by many people. Static electricity was
produced by rubbing an insulating object such as a glass or ebony or
sulphur cylinder with a cloth or animal fur (a cylindrical shape
was better than a sphere because it could be rubbed vigourously).
The presence of static electricity could easily be demonstrated by
bringing near any of a wide variety of materials, such as bits of paper
or silk ribbon.
These static electricity demonstrations generated high voltages but only very tiny currents. As a result the static properties of electricity were widely known but the magnetic effects were never observed because they require much larger electric currents than can ever be produced by static methods. Furthermore, anyone studying the magnetic effects has to have a steady electric current available over a significant period of time – at least several seconds, and several minutes is much better.
Volta's breakthrough invention suddenly made it possible for
people to have a reliable and predictable supply of significant
electric current. It is no accident that many important
electrical discoveries came in the next few decades.
In 1820, Oersted's observation of the magnetic effect of electric
current was reported; then Schweigger's galvanometer (the ancestor of
all of the now-familiar electrical instruments with a needle moving
across a marked dial); and in 1831, there were the crucial
discoveries by Faraday in England and Henry in the United States –
all involving some version of Volta's battery.
Useful electric telegraph systems, powered by batteries, began
to appear. In 1809, von Soemmering demonstrated a
working electric telegraph to the Munich Academy of Sciences – although
not very practical because it required 35 separate wires between
the sending and receiving ends, von Sommering's telegraph was able
to deliver messages reliably at a distance by electric current.
This quickly became widely known and stimulated others to
activity. In his 1835 trip to Germany, William Cooke saw the
electric telegraph built by Professor Muncke at Heidelberg; on
returning to England, Cooke worked with Wheatstone to develop an
electric telegraph good enough to be put into regular use in
May 1838. All of these telegraph systems, and all commercial
telegraph lines throughout the rest of the 1800s and well into the
1900s, were powered by batteries – all of them being close relatives of
Volta's battery made of two different metals immersed in a chemical
solution.
Alessandro Volta by Russell Naughton
Alessandro Volta by Pierre Roberge
Alessandro Volta by Wikipedia
Postage stamp: Alessandro Volta
Before 1820, the only magnetism known was that of iron magnets and of
lodestones
(natural magnets). This was changed by Hans Christian Oersted, an
obscure professor of science at the University of Copenhagen,
Denmark. In April 1820 Oersted arranged in his home a science
demonstration for friends and students. Using a voltaic battery
to supply electric current, he planned to demonstrate the heating of a
wire by an electric current, and also to carry out demonstrations of
magnetism with a compass needle mounted on a wooden stand. While
performing his electric heating demonstration, Oersted noted to his
surprise that every time the electric current was switched on, the
compass needle moved. Most surprising, the compass needle pointed
in a direction perpendicular to the wire. When the current in the
wire was reversed, the compass needle also reversed, pointing in the
opposite direction but still at a right angle to the wire. This
was the first demonstration of a connection between electricity and
magnetism. We now use the words "electromagnetic" and
"electromagnetism" to refer to the combined effects of magnetism and
electricity. Today, our world is dominated by electromagnetic
technology.
The Electromagnetic Revolution: Oersted's discovery
by the Magnetism Group, Physics Department, Trinity College, Dublin
Hans Christian Oersted by David Stern
Hans Christian Oersted by Russell Naughton
Hans Christian Oersted by Pierre Roberge
Hans Christian Oersted by Wikipedia
Lodestone by Wikipedia
A Ridiculously Brief History of Electricity and Magnetism Ross L. Spencer
A Brief Chronological History of Great Discoveries in Electricity Rudolf F. Graf
William Sturgeon was a shoemaker's apprentice as a boy, then he joined the British army where he got an education. He became interested in electricity while watching a severe thunderstorm in Newfoundland. He returned to civilian life in England and began experimenting with electricity. In the early 1820s, Sturgeon found that a coil of wire wound around a piece of iron would produce strong magnetic effect when the wire coil was connected to an electric battery. In 1825 he demonstrated his invention, displaying its strength by lifting nine pounds [4kg] with a seven-ounce [200g] horseshoe-shaped bar of iron wrapped with about eighteen turns of wire, connected to a one-cell (low voltage) battery. This was the first electromagnet – capable of lifting twenty times its own weight. It could hold the suspended weight indefinitely with no sign of fatigue or lessening of the magnetic effect so long as the battery was connected, but the suspended weight dropped immediately if the battery was disconnected (a discovery that later was used with longer wires to transmit messages by electric telegraph to faraway places). Sturgeon's 1825 electromagnet was an early practical demonstration of the close connection between electricity and magnetism that since then has had an enormous influence on communications technology, and many other scientific fields. In the 1830s, Sturgeon made his living partly by teaching; one of his students was James Prescott Joule.
William Sturgeon by Wikipedia
William Sturgeon by the Center for the Study of Technology and Society
Development of the Electromagnet by John D. Jenkins
What is now known as Ohm's law first appears in a book printed in Berlin in 1827: Die galvanische Kette, mathematisch bearbeitet (The Galvanic Circuit Investigated Mathematically). In the mid-1820s, Georg Simon Ohm, professor of mathematics at the Jesuit College of Cologne, Germany, had been studying how electricity is conducted through various materials, using a variety of voltages. He discovered that, in a particular material arranged in a particular form – an iron wire, or a copper bar, or a lead cylinder, etc. – the electric current in the circuit is directly proportional to the number of cells in the battery. This is what is now known as Ohm's law, one of the most fundamental principles of electricity.
In January 2007, several copies of the first edition of Die galvanische Kette, mathematisch bearbeitet by G.S. Ohm, 1827, are available from antique book dealers and listed on the WWW. One copy in good condition can be purchased from a dealer in Los Angeles for US$25,000. Another copy is available from another dealer for C$30,627. A third copy for sale in the Netherlands is priced at €20,000.
In 1831, Michael Faraday began his great series of
experiments in which he discovered electromagnetic induction, the
ability of a changing magnetic field to produce a voltage in a nearby
conductor. The important term is "changing" – it is not
the magnetic field, weak or strong, but a change
in the magnetic field that generates a voltage in any nearby
conductor. Any time a conductor (wire loop) is in the influence
of a magnetic field that varies in strength, an electric current is set
up in the conductor. It is this effect, that we now call
"electromagnetic induction," that is the basis of present-day
generation of electric power, the transmission of information using the
electromagnetic spectrum (radio, television, radar, microwave, etc.)
and many other useful applications of electricity.
Michael Faraday by Russell Naughton
Michael Faraday by Pierre Roberge
Michael Faraday by Encyclopedia Britannica 1911
Michael Faraday by Wikipedia
Electromagnetic induction by Wikipedia
Faraday and Henry
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|
Today, the unit of measure of electrical capacitance is called the farad,
named for Michael Faraday. Today, the unit of measure of electrical inductance is called the henry, named for Joseph Henry. Note: "henry" (lower-case "h") is the name of the unit of inductance while "Henry" (upper-case "H") is the name of the man. Similarly for "farad" and "Faraday", also "ampere" and "Ampere" "ohm" and "Ohm", "volt" and "Volta", and "coulomb" and "Coulomb". Having a measuring unit named for you is the highest accolate that a scientist can achieve. In the field of electricity, along with the farad and the henry, we now have the volt (Alessandro Volta), the ampere (Andre Ampere), the coulomb (Charles Augustin de Coulomb), the ohm (Georg Simon Ohm), the gauss (Johann Karl Friedrich Gauss), and the maxwell (James Clark Maxwell). The hertz (Heinrich Rudolf Hertz) is not an electrical unit, but it is often used by everyone working with electrical technology. Likewise, the watt (James Watt) is not an electrical unit, but it appears everywhere that electricity is used. |
In 1830, Joseph Henry began experimenting with
insulated wires wound an iron core, and succeeded in making powerful
electromagnets. In 1831 at Yale University, he demonstrated
a big electromagnet that could lift 2300 pounds 1045kg,
the largest in the world at that time. These magnets were powered
by an electric current from a battery made according to Volta's design.
While experimenting with these magnets, Henry needed to turn
the current on and off many times, by making and breaking the
circuit. Whenever the magnet circuit was broken, he observed a
large spark that was generated at the point where the break was
made. Over time, Henry built bigger electromagnets with more iron
in the core and more turns of wire around the core, and he noticed that
the larger the electromagnet, the more powerful the spark when the
circuit was broken.
(For magnets of this size, these circuit-breaking sparks
can be impressively powerful, even frightening. While opening
the field circuits of hydroelectric generators – electrically
identical to Henry's electromagnets – I've seen a few that
deserve adjectives such as vicious or dangerous. – ICS)
In 1830-1831, he deduced the property known as self-inductance, the
inertial characteristic of an electric circuit. The
self-inductance of a circuit tends to prevent the current from
changing; if a current is flowing, self-inductance tends to keep it
flowing; if an electromotive force is applied self-inductance tends to
keep it from increasing.
Joseph Henry by Alexander Leitch
Joseph Henry by Roger Sherman
Joseph Henry by Russell Naughton
Joseph Henry by Encyclopedia Britannica 1911
Joseph Henry by Wikipedia
In the decade 1880-1890, the most important advance in electrical physics was that which originated with the astonishing researches of Heinrich Rudolf Hertz. This illustrious investigator's great discovery was an experimental realization of a suggestion made by G.F. Fitzgerald in 1883 as a method of producing electric waves in space...
Click on the image for a full size view
Heinrich Hertz was the first to demonstrate the existence of radio waves. In 1888, in a corner of his physics classroom at the Karlsruhe Polytechnic in Berlin, Hertz generated electric waves using an electric circuit. The circuit contained two metal rods separated by a short gap, and when sparks crossed this gap strong oscillations of high frequency were produced. Hertz proved that these waves were transmitted through air by detecting them with some distance away with a simple wire loop. He discovered the progressive propagation of electromagnetic action through space, and measured the length and speed of these electromagnetic waves. He also showed that like light waves they were reflected and refracted. Hertz also noted that electrical conductors reflect the waves and that they can be focused by concave reflectors. He found that nonconductors allow most of the waves to pass through. These waves, originally called Hertzian waves but now known as radio waves, conclusively confirmed Maxwell's prediction on the existence of electromagnetic waves, both in the form of light and radio waves. Today, the term "hertz" (short form "Hz") is used as the unit of frequency for an electromagnetic oscillation or wave.
Heinrich Hertz by Russell Naughton
Heinrich Hertz by Pierre Roberge
Heinrich Hertz by Encyclopedia Britannica 1911
Heinrich Hertz by Wikipedia
Evidence for Electromagnetic Waves by University of Colorado
Electric Wavespage 203 |
Electric Wavespage 204 |
Electric Wavespage 205 |
Electric Wavespage 206 |
Electric Wavespage 207 |
Electric Wavespage 208 |
Click on thumbnail for full size view
The encyclopedia article "Electric Waves," (above)
by
J.J. Thomson, several times refers to "Leyden Jars,"
(the first electric capacitors).
Leyden Jars
Leyden Jars by PV Scientific Instruments
Leyden Jar by Wikipedia
Leyden Jar by Roger Curry
The experiments of Heinrich Hertz on electromagnetic waves form
"one of the greatest contributions ever made to experimental physics."
— Sir J.J. Thomson
In 1897,
Joseph John Thomson discovered the
first experimentally-proven atomic particle, the
electron.
Credit is due to Edouard (Edward) Branly (1844-1940) of France for inventing the coherer, the first practical instrument for detecting Hertzian waves. It consisted of two small metal plates or cylinders with wires attached, placed inside each end of a glass tube containing loose zinc or silver particles (filings). The instant an electric discharge – a spark or an arc – occurred in the vicinity the coherer's metallic filings became conductive, and then if it was tapped lightly its conductivity vanished and it became an insulator. In practice the tapping was done automatically by a tapper, similar to a small hammer, which acted each time the coherer became conductive. When connected in a low-voltage circuit, in its ordinary state a coherer had a resistance of millions of ohms, but this dropped dramatically to hundreds of ohms when electromagnetic waves were produced in the vicinity.
A Branly coherer consists of a glass tube filled with metal filings which acts as an insulator when placed in a circuit with a low-voltage battery. However, if an electric spark occurs anywhere in the vicinity, the coherer becomes a conductor and allows current to flow in the circuit. When the tube is tapped lightly, it becomes an insulator again and interrupts the current. This phenomenon was described by Branly in 1890. There has never been a satisfactory explanation of how a coherer works. Nevertheless, we can describe its behavior, even if we don't fully understand all the details of why it works.
The coherer was a very useful device in the early days of experimentation with electromagnetic waves. It was widely used from the early 1890s until about 1910, when what we now call vacuum tube rectifiers became available.
Edouard Branly by Wikipedia
Eugene Edouard Desire Branly by Russell Naughton
A Radio Receiver Using a Branly Coherer as a Detector
Electrical transport in granular media: the Branly Effect
The Branly Prize 2004
In lecture delivered in 1891, Frederick T. Trouton
noted that if an electrical alternator could somehow be run fast
enough, it would generate electromagnetic radiation. This
approach was later explored by Fessenden and Alexanderson.
United States Early Radio History by Thomas H. White
When Heinrich Hertz, who discovered wireless waves,
died in 1894, Augustus Righi – professor of physics at Bologna
University, a pioneer of work on wireless waves, and a friend of
Marconi's family – wrote an obituary that fired Marconi with the
idea of deploying these waves for telegraphy without wires between
sender and receiver ('wire-less').
Augusto Righi by Russell Naughton
In the early 1890s, Alexander Popov was working in Russia on a way to detect thunderstorms. Anyone who has listened to an AM radio receiver while a thunderstorm is active in the vicinity, can understand how a radio receiver works as a lightning detector. In the early 1890s, Popov was working on a way to predict thunderstorms, by using atmospheric radio waves to detect the occurrence of distant lightning strokes. Popov's work focused on lightning detection, but this can also be described as the ability to receive radio waves. In 1894 he built an apparatus that could register electrical disturbances due to lightning, and then suggested that it could be used for receiving man-made signals. It contained a coherer. Developed as a lightning detector, Popov presented it to the Russian Physical and Chemical Society on 7 May 1895. Without question, this was a primitive radio receiver. In 1896, he demonstrated the transmission of radio wave signals between different parts of the University of St. Petersburg.
Alexander Stepanovich Popov by Wikipedia
Alexander Stepanovich Popov by Saint Petersburg Electrotechnical University
Engineering Hall of Fame: Alexander Popov by IEEE, December 2005
Alexander Stepanovich Popov
Alexander Stepanovich Popov by Russell Naughton
Alexander Popov: Russia's Radio Pioneer by James P. Rybak
Russian Stamps Showing Alexander Popov
In February 2003, the History Committee of the IEEE
acknowledged Marconi's early wireless experiments in Salvan,
Switzerland, as a "Historical Milestone". A commemorative plaque
was dedicated on behalf of the IEEE by Raymond Findlay, IEEE Past
President, on 26 September 2003, in the presence of both Princess
Elettra Marconi-Giovanelli, youngest daughter of Guglielmo Marconi, and
Pascal Couchepin, president of Switzerland. The speakers recalled
that Salvan had been the theatre of a major event in the history of
electrical engineering and of mankind, as Marconi's discovery brought
people closer together. Through his intelligence and doggedness
of purpose, Marconi, father of wireless communications, provided an
example of creativity and inventiveness to younger generations.
President Couchepin concluded hoping that this ceremony would prompt us
to meditate on the importance of science and technical progress in our
civilization...
IEEE: Marconi Milestone in Salvan, 26 September 2003
On this spot in 1895, with local assistance,
Guglielmo Marconi carried out some of the first wireless experiments.
This was the beginning of Marconi's critical involvement in wireless
radio...
Photograph of the IEEE Marconi Milestone 1895 plaque
Salvan: Cradle of Wireless Microwave Journal, February 2006
Historical overview of Gugliemo Marconi's
early wireless experiments in Salvan, a resort town in the Swiss
Alps... Overlooking the village of Salvan is a flat-topped erratic rock
called the
Shepherdess Stone, on which Marconi set up his transmitter...
Guglielmo Marconi is awarded British Patent number 12039, the world's first patent for a system of telegraphy using Hertzian waves (radio).
At the Royal Institution in London, England, on Friday 29 January 1897, Jagdish Chandra Bose delivered his famous "Friday Evening Discourse" on "Electromagnetic Radiation and the Polarisation of Electric Rays". The Friday Evening Discourse tradition had been started in 1826 by Michael Faraday, and in the late 1800s was one of the most prestigious platforms for announcing new scientific discoveries. Some of the most prominent British scientists were members of the Royal Institution and participated in these discourses. In this 1897 lecture, Bose demonstrated his devices for the generation and detection of radio waves. More than five hundred people including Oliver Lodge, James John Thomson and Lord Kelvin had assembled to hear Bose. The lecture was not only praised but it was considered valuable enough for publication in the Transactions of the Royal Society. The University of London conferred on him the D.Sc. degree for his work on electric waves.
The date of Bose's "Friday Evening Discourse" has been reported in some sources as Friday 19th January 1897, or as Friday 19th July 1897. The problem is, in the year 1897, January 19th was a Tuesday, and July 19th was a Monday. However, the 1897 calendar shows January 29th as a Friday.
Jagadish Chandra Bose by Vigyan Prasar
Department of Science and Technology, Government of India
In 1897, with the help of wealthy relatives, Marconi founded the Wireless Telegraph and Signal Company, with Colonel Jameson Davis, a cousin of Marconi, as the first Managing Director. The company was registered (incorporated) on 20 July 1897. On 24 March 1900, the name was changed to Marconi Wireless Telegraph Company Limited.
On this day, the name of the Wireless Telegraph and Signal Company was changed to Marconi's Wireless Telegraph Company Limited. Samuel Flood Page became Managing Director on the same day.
The Marconi International Marine Company was incorporated on this day, to handle Marconi's marine (ship communications) business.
"...communication can be maintained while the vehicle is traveling..."
Marconi has found that the equipment works "for the transmission of messages over short distances, up to about 30 miles [50km]"
Military Automobile for Wireless Telegraphy Western Electrician, 27 July 1901
On this day, Marconi and his assistants were able to hear the three short bursts of the Morse code 'S' at the receiving station set up in a hospital in Signal Hill, St. John's Newfoundland. This first transatlantic telegraph transmission originated in Poldhu in Cornwall, England, 2100 miles [3400km] across the Atlantic Ocean.
In February 1902, a Marconi receiving station was installed on the steamship Philadelphia, proceeding from Southampton to New York. The receiving aerial was rigged to the mainmast, the top of which was 197 feet above the level of the sea, and a syntonic receiver was employed, enabling the signals to be recorded on the tape of an ordinary telegraph recorder. On this voyage readable messages were received from Poldhu (in Cornwall, England) up to a distance of 1550 miles, and test letters were received as far as 2100 miles.
1550 nautical miles = 2900km
2100 nautical miles = 3900km
It was on this voyage that Marconi made the
interesting discovery of the effect of sunlight on the propagation of
electric waves over great distances. He found that the waves were
absorbed during the daytime much more than at night and he eventually
reached the conclusion that the ultraviolet light from the sun ionized
the gaseous molecules of the air, and ionized air absorbs the energy of
the electric waves, so that the fact was established that clear
sunlight and blue skies, though transparent to light, serve as a fog to
the powerful Hertzian waves of wireless telegraphy. For that
reason the transmission of messages works better between England and
Newfoundland across the North Atlantic, than in the clearer atmosphere
of lower latitudes.
— Excerpted from:
The Story Of Electricity by John Munro, 1915
Marconi's 1902 experiments on the Philadelphia were performed at 366 metres wavelength (820 kilohertz). These effects are very frequency dependent, as Marconi and others gradually appreciated in the following years.
"On This Day" (in history), The National Post, 15 December 2006
• Messages are sent and received by ships at sea...
• The amount of electric power available aboard an ordinary passenger liner is
sufficient to send wireless messages 150 miles [280km] under favorable
circumstances. Knowing the sailing-days and speeds of the ships that
they are likely to meet or overtake, the navigating officers of a liner
can calculate roughly when they are likely to come within the required
radius of another floating telegraph office...
• Sometimes a vessel has been in almost daily communication with
others all the way across the North Atlantic. Such was a recent
experience of the Ivernia...
• To borrow money while at sea, from a ship 100 miles [190km] away,
would have been an impossible feat a year or so ago, but recently it
was accomplished by telegraph...
• The Marconi service to and from the Nantucket South Shoals
lightship is so reliable "that during a whole year there was but one
interruption".
The Work of a Wireless Telegraph Man The World's Work, February 1904
Marconi International Marine Communication Company, Circular No. 57:
It has been brought to our notice that the call "C.Q." (All Stations), while being satisfactory for general purposes, does not sufficiently express the urgency required in a signal of distress.
Therefore, on and after the 1st February, 1904, the call to be given by ships in distress or in any way requiring assistance shall be "C.Q.D."
This signal must on no account be used except by order of the Captain of the ship in distress, or other vessels or stations retransmitting the signal on account of the ship in distress.
All stations must recognise the urgency of this call and make every effort to establish satisfactory communication with the least possible delay.
Any misuse of the call will result in the instant dismissal of the person improperly employing it.
(CQ still means, literally, "attention" but in amateur radio its meaning is perhaps more accurately described by Thomas Raddall who compared it to yelling "Hey, Mac!" down a drain pipe.)
Alexanderson alternator by Wikipedia
Ernst Alexanderson by Wikipedia
Ernst Alexanderson, Pioneer Inventor by Barry Mishkind, 1998
Ernst Alexanderson by Mary Bellis
Transoceanic Radio Communication by Ernst F.W. Alexanderson, 1920
The Power that Made Radio Realistic by the Federal Communications Commission
Historical Review of Continuous Wave Radio Frequency Power Generators by Frank Lotito, 2002
An international radio agreement was signed at Berlin, Germany on 3 November 1906, by Germany, The United States of America, Argentina, Austria, Hungary, Belgium, Brazil, Bulgaria, Chile, Denmark, Spain, France, Great Britain, Greece, Italy, Japan, Mexico, Monaco, Norway, The Netherlands, Persia, Portugal, Roumania, Russia, Sweden, Turkey, and Uruguay.
Article 6: The High Contracting Parties shall notify one another of the names of coastal stations and stations on shipboard referred to in Article 1, and also of all data, necessary to facilitate and accelerate the exchange of wireless telegrams, as specified in the Regulations.
Article 9: Wireless telegraph stations are bound to give absolute priority to calls of distress from ships, to similarly answer such calls and to take such action with regard thereto as may be required.
This international agreement (treaty) went into effect on 1 July 1908.
"...every auto will be provided with a portable wireless telephone..."
In case of accident or breakdown, the phone can be used to call for help.
The Collins Wireless Telephone Modern Electrics, August 1908
(Brief)
Reminiscences of Old-Timers: William Dubilier
Radio-Craft, March 1938
(Complete)
Reminiscences of Old-Timers: William Dubilier (.pdf)
Gold Country Nuggets, Newsletter of the Nevada County Amateur Radio Club
Nov-Dec 2000
The SS Republic, a Royal Mail Ship (RMS) authorized
to carry both the British and U.S. mails, was flagship of the White
Star Line steamship company's Boston-European Service, and one of the
largest and most luxurious passenger liners in the world. On the
morning of 23 January 1909, the Republic, outbound from New York, was
rammed by the Florida, in heavy fog off the coast of Massachusetts.
Republic immediately began sending distress signals by Marconi
wireless. (This is reportedly the first practical application of the
then recently invented wireless in an open sea rescue effort.)
Although the Republic eventually sank, it stayed afloat long enough to
transfer all of its surviving crew and passengers to safety, and also
radioed for assistance from other ships, most importantly the Baltic.
The Republic's initial "CQD" distress signal, sent by Marconi operator
Jack Binns, was picked up by the Marconi land station "MSC" at
Siasconsett, Nantucket Island, Massachusetts. In this incident,
probably 1,500 lives saved by means of radio.
Operator Binns' Wireless Log Modern Electrics, February 1909
Within minutes of the collision, the Republic's Marconiman sent
the "CQD" ("CQ" meaning "[Attention] All Stations", and "D" meaning
"Distress"), the predecessor to today's "SOS" distress signal, over the
airwaves to the world at large. No less than seven ships, including
several major liners, responded. This was the first practical
demonstration of this "new" technology's ability to aid victims of
disasters at sea, and this "miracle" captured the wide attention. It
was one of the world's earliest "breaking-news" "live" mass-media
event. The Republic's passengers were transferred twice, first to the
less damaged Florida, then to the called-to-the-rescue White Star liner
Baltic. This double-transfer open-sea rescue maneuver remains the
largest on record.
RMS Republic
The 1909 Nobel Prize in Physics was awarded jointly to Guglielmo
Marconi and Carl Ferdinand Braun, in recognition of their contributions
to the development of wireless telegraphy.
Presentation Speech, Nobel Prize in Physics, 10 December 1909
Nobel Foundation Official Web Site
Guglielmo Marconi - Banquet Speech, 10 December 1909
Nobel Foundation Official Web Site
Guglielmo Marconi - Biography
Nobel Foundation Official Web Site
Swedish stamps 1969: the winners of the Nobel Prizes in 1909 including Marconi
Guglielmo Marconi: radio star by Physics World
There cannot be many people who screwed up at school, failed to get into university, and then went on to win a Nobel Prize for Physics. But at least one did, and with good reason: he made radio happen. In a few years of manic activity, Guglielmo Marconi managed to transform an obscure piece of maths into a social upheaval that makes the dot.com phenomenon look about as radical as a new bike for your postman... No intellectual, Marconi earned his Nobel prize the hard way by dragging a great chunk of physics out of the lab and holding it up for the world to see, approve and, more importantly, buy...
In 1903, Valdemar Poulsen began development of an arc transmitter which
increased the frequency range of Duddell's Singing Arc (1900) from
10 kHz to 100 kHz, enabling speech to be transmitted up to a
radius of 150 miles. By 1920 the Poulsen Arc transmitter was as
powerful as 1000kW with ranges of up to 2500 miles. The Poulsen
Arc Transmitter was extensively used in radio before the advent of
vacuum tube technology in the mid-1920s.
In 1909, the Poulsen Wireless Telephone & Telegraph
Company was founded in San Franscisco. The associated Poulsen
Wireless Corporation of Arizona was incorporated in 1910, and then
the Federal Telegraph Company. The Federal Telegraph Company,
specializing in manufacturing arc transmitters, brought Poulsen's arc
transmitter to the United States. When NAA, the United States
naval spark station at Arlington, Virginia, went into commission
in 1912, an arc transmitter also was installed; thus two rivals,
Fessenden with the spark, Poulsen with the arc met on a common proving
ground. Arc transmitters up to 500 kilowatts were
tested by the U.S. Navy. One main disadvantage was found in
that the arc emitted harmonics and arc mush. The arc produced so
much heat that a water cooling system was required.
Nevertheless, during the First World War a number of United
States Navy battleships carried arc transmitters. The U.S.S.
George Washington, which took President Wilson to the Peace Conference
in France in 1919, was equipped with an arc transmitter in hopes
that communication might be maintained all the way across the North
Atlantic. It was a triumph for radio when the Washington entering
the harbor at Brest, France, sent radio signals from its arc
transmitter which were picked up at Otter Cliffs, Bar Harbor, Maine,
and a 600-word message (sent in Morse code) was received without the
loss of a word.
L to R: Doug Perham, F. Albertus, and Peter V. Jensen.
Jensen left shortly after this photo was taken
to start the Magnavox [loudspeaker] Co.
Image source:
http://www.acmi.net.au/AIC/POULSEN_BIO.html
Valdemar Poulsen by Russell Naughton
Valdemar Poulsen by Wikipedia
Ocean Beach Wireless Transmitting Station by Virtual Museum of San Francisco
100 Years of Magnetic Recording 1898-1998: Poulsen's Patent
A dramatic demonstration of the value of wireless telegraphy in police work – the capture of Dr. Crippen and Miss Le Neve off Father Point, Quebec.
The following was published in 1911:
Electric wave telegraphy (the wireless telegraph) has
revolutionized our means of communication from place to place on the
surface of the earth, making it possible to communicate instantly and
certainly between places separated by several thousand miles, whilst at
the same time it has taken a position of the greatest importance in
connection with naval strategy and communication between ships and
ships and the shore in time of peace. It is now generally
recognized that Hertzian wave telegraphy, or radio-telegraphy, as it is
sometimes called, has a special field of operations of its own, and
that the anticipations which were at one time excited by uninformed
persons that it would speedily annihilate all telegraphy conducted with
wires have been dispersed by experience. Nevertheless,
transoceanic wireless telegraphy over long distances, such as those
across the Atlantic and Pacific oceans, is a matter to be reckoned with
in the future...
Wireless Telegraphy by Encyclopedia Britannica 1911
Article 11 requires some ships to have emergency radiotelegraph installations.
Article 21 dictates a distress signal for ships, and requires ships to suspend correspondence and reply when distress signals are heard.
Article 45, requires countries to supply their coast stations with meteorological telegrams, and requires them to facilitate the communication of the information regarding wrecks and casualties at sea.
Beginning in 1912, ten years before officially-licensed radio broadcasting began in the United States, Charles David Herrold transmitted weekly entertainment radio programs from his Herrold College of Wireless and Engineering in San Jose, California, to a small but loyal audience fron San Jose to San Francisco. This was before vacuum tubes, and his broadcasts were received by homemade crystal sets. He continued his weekly broadcasts until 1917 – when the United States entered World War One, the government shut down all private radio stations.
Note, by Mike Adams: – In our research, my
co-author Gordon Greb and I traveled to the Clark Papers
Collection at the Smithsonian to determine if there were any other
individuals in the world who had a radio station on the air as early as
Charles Herrold did in 1909. We found a few one-time
experimenters, but none who, as Herrold did:
(1) were broadcasting entertainment programming,
(2) on a regular basis,
(3) pre-announced,
(4) to a known audience...
Charles "Doc" Herrold by Russell Naughton
Doc Herrold's San Jose Broadcasting Station by John Schneider
Charles Herrold by Wikipedia
Charles Herrold by Mike Adams and Gordon Greb
Charles Herrold of San Jose California was on
the air every day between 1909 and 1917 broadcasting music and
information to an audience of experimenters who listened on home made
crystal radios...
Official Proclamation, 12 September 1994 by the Mayor of Oakland, California
A special section of Lloyd's Register is devoted to
ships fitted with wireless apparatus, and rates of insurance on such
ships are considerably lower than on vessels not so equipped...
The advance of maritime wireless telegraphy to the indispensable
part it now plays in the daily round of a ship at sea has been
extraordinarily rapid. At the beginning of 1909, after
eight years of development work, there were 125 ships of the
mercantile marine fitted with Marconi apparatus. By the end
of that year the number had risen to nearly 300; today the total
is well over 1500. On the North Atlantic route
– where, owing largely to the establishment by the Marconi
Companies of shore stations in Great Britain, Canada, and the United
States, wireless telegraphy has seen its greatest development –
182 vessels, comprising the principal vessels on all the leading
lines, are equipped, and many others are in course of being
fitted. On the South Atlantic route the figures are also
remarkable, and the number of ships fitted during the past two years
has increased almost threefold. On South African routes
similar rates of increase are to be noted...
Wireless Telegraphy and the Mercantile Marine
The Yearbook of Wireless Telegraphy and Telephony, 1913
The Otter Cliffs Naval Radio Station, located on Mt.
Desert Island, Maine, was commissioned on 28 August 1917, under
the command of then-Ensign Alessandro Fabbri. Fabbri, in
patriotic fervor after the declaration of war against Germany, cleared
the land, and built and equipped the station. He then offered it
to the government as a Navy radio station to support the war effort, in
exchange for a commission in the Naval Reserve and assignment as
officer in charge.
Fabbri sought to make Otter Cliffs the best radio station on
the east coast of the United States. Eventually, his efforts were
recognized in promotions to lieutenant junior grade in 1918, and
lieutenant the following year. Fabbri, who was released from
active duty in 1919, was eventually awarded the Navy Cross for
developing the "most important and most efficient station in the
world," according to U.S. Navy documents that detailed Fabbri's
contributions.
Otter Cliffs Radio Station continued to function long after
Fabbri left. Because of the lack of man-made electromagnetic
interference within many miles, and the unobstructed span of ocean
water between there and Europe, Otter Cliffs was among the best radio
sites along the east coast of the United States, and could receive
signals from Europe when no other station in the United States
could. It had been valuable in World War One, when radio
receivers were rather primitive.
By 1930, the station was handling weather reports from Iceland
and Newfoundland, and emergency traffic from Europe, when atmospheric
conditions were so bad that Portsmouth, Maine; Boston, Massachusetts;
and Washington D.C., could not copy the overseas transmissions.
On 28 February 1935, the U.S. Navy Radio and
Direction Finding Station Winter Harbor was officially commissioned, as
a replacement for Otter Cliffs. The new radio receiving station
was located on Big Moose Island, Maine, at the tip of Schoodic
Peninsula about five miles across the mouth of Frenchman Bay from Otter
Cliffs. This station continued to operate until June 2002.
End of an Era: NSGA Winter Harbor to Close Its Doors
NSGA: Naval Security Group Activity
Chapter XXV: Operation of the World's Largest Radio System
History of Communications-Electronics in the United States Navy
Captain Linwood S. Howeth, USN (Retired), 1963
Radio Corporation of America (RCA) was incorporated to control US communications patents of General Electric, AT&T, Westinghouse, and United Fruit Companies.
RCA acquires the assets of wireless radio company American Marconi from British Marconi.
David Sarnoff becomes General Manager of RCA.
This was the first ever advertised public broadcast program. A song recital by famous soprano Dame Nellie Melba was broadcast live, using a Marconi 15 kW telephone transmitter, from the Marconi works in Chelmsford, England.
The British Broadcasting Company (BBC) is formed by Marconi and five other companies.
The BBC officially began daily domestic radio service broadcasting with the 6:00pm news read by Arthur Burrows from 2LO, Marconi House, London. Manchester and Birmingham stations began operation the next day.
The British Government decides to control all broadcasting.
Wireless — Yesterday and Today
Wireless communication, as the term implies, enables information
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The basic measure of bandwidth is hertz, or wave cycles per second.
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