Communication Systems and Technology

Please Note:
The original copy of this page was prepared and  maintained by R. Victor Jones
Comments to: jones@deas.harvard.edu.
His Last update was August 20, 1999

I am making a copy of this page to share with students and make sure it does not disappear from the WWW
Anthony Luscre - ZTLearn.com

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A Chronology of Communication Related Events

4004 BCE - 1996 AD

A Statement of Purpose
 References and Sources  

-4004:
 According to Genesis with dating by Archbishop James Ussher (source-1 and source-2).  Portrait of Archbishop Ussher (source)
"And God said Let there be light: and there was light."
The first verses of Genesis give to light an absolute precedence in Creation: precedence over the sun which was created on the fourth day and over man who was created on the last day.   These words imply a theory of the nature of light  which attributes to light an existence of its own, independent of its source and of its receiver.
-2900:
Hieroglyphics, characters with a recognizably graphic character, are in use.


-1200:

In the Iliad, Homer tells of a chain of beacon fires prearranged to signal the return of Agamemnon's fleet to Mycenae and, thus, gave Clytemnestra and Aegisthus time to arrange the assassination of Agamemnon.

Richard Hennig, in 1908, calculated the approximate distances (total 600 km) between the stations that Aeschylus described the his drama Agamemnon: (source)
 

Location
Modern Name
Altitude (m)
Distance (km)
Troy
Troy
100
0
Mt. Ida 
Kaz Dagi 
1774
 55
Lemnos 
Skopia at Limnos
 430
  154
Mt. Athos
Athos
2033 
70
Macistus
 Kandilion at Euboea
1209
 177
 Messapius
Ktipas 
1020
30
 Cithaeron
Elatias
1410
 25
Mt. Aegiplanetus
Mt. Jeraneia
 1370
30
Arachnaean
Hgt  Arna 
 1199
 50
Mycenae
Mycenae
150
  20


 -580:

According to Greek tradition, Thales of Miletus (624-546 BC) is the first to have investigated magnetic and electric forces.  In particular, he is said to have noticed the phenomena of static electricity acquired by amber (in Greek elektron) -- i.e.,amber when rubbed with a piece of silk or fur develops the ability to attract little objects such as feathers. (source-1, source-2 and source-3)
-500
Greek and Chinese philosophers describe the principles of optics.

The philosophical concepts developed by the Greeks lie at the root of all later philosophical speculation in the western world.  The intuitive hypotheses of the 'golden age' (fifth and fourth centuries BC) philosophers has foreshadowed many theories of modern science and has provided a foundation for modern scientific thought.  The majority of the ideas  of the Greek philosophers deserve  to be consider as strictly logical reasoning, carried out not only with common sense , but even with noticeable acumen.  It was inevitable that these sages should turn their attention to light, but they were less interested in determining the nature of light than in explaining the mechanism of vision.  The main goal of thinkers was to learn to understand man, his functions and his facilities.  In the fifth century BC there was, without a doubt, an unceasing attempt to determine the link between the eye and the object seen.  Nowadays we call this link light  without reservations and without thinking as if it were an evident reality because of the studies and of the discussions which have gone on for over two thousand years.  In the fifth century BC this type of link between the eye and the object seen was rightly considered as a possible solution, but not the only one.  The Pythagoreans held that the link could be thought to be due to 'something' (quid ) which was emitted by the eye and traveled towards the object while the Atomists of the school of Democritus favored a theory of an emission of 'something' which traveled towards the eye from the object.  Empedocles of Agrigentum supported the notion of the coexistence of somethings' traveling in opposite directions.  Even with these conjectures, all the possible solutions were not exhausted, since some other type of link could be imagined, without any motion in either direction, but merely a modification of the medium interposed between the eye and the object seen (Aristotle).

-490:
The first marathon: In the Battle of Marathon
"the Persians lost seven ships to the Athenians.  However, Miltiades and his Athenian army realized that the Persian fleet could sail and attack the undefended city of Athens.  He called upon Phidippides to run to Athens to bring the news of victory and a warning of the approaching Persian ships.  Phidippides’ 26-mile run from Marathon to Athens, the first marathon ever, was successfully completed in about three hours.  Phidippides became a martyr, dying from exhaustion after fighting all day and completing the run.  However, he successfully warned the Athenians, and when the Persian fleet arrived at Athens, Athenian soldiers were ready to protect their land.  Upon seeing the prepared Athenian army, the Persians turned and sailed back to Persia in defeat...." (source)
-431 to 404:
Thucydides' (460 - 399) History of The Peloponnesian War is replete with references to the use of signal fires in various military operation of the Second Pelopennesian War. discusses in considerable detail the role of signal fires in military operations (The Early History of Data Networks quotes some of these references.  Richard Crawley has published an online translation of Thucydides which is mirrored as an annotated local copy).

Scott Rusch discusses a particularly interesting early example of the use of signal "jaming" in the seige of Plataea:

"...Meanwhile, beacon fires indicating danger from the enemy were lit by the garrison of the siege wall and flashed towards Thebes.  But the Plataeans in the town raised many beacon fires from their walls at the same time, having prepared for this action beforehand, in order that their enemy's beacon signals might be rendered unintelligible and the Thebans, mistaking the situation, might defer bringing aid until the escapees had gotten away.  This must be one of the first attempts to jam a signal in the history of communications.  Based on the number and position of the fires they lit, the besiegers apparently could send a variety of pre-arranged messages to Thebes. The Plataeans had seen that they could do this, but did not know the precise 'code' arrangement, so they simply lit a lot of fires and hoped to confuse the Thebans..." (source)
-350 or 360
As described by the historian Polybius (ca. 200-118 ),  "Aeneas the Tactician"  develops a "hydro-optical telegraph" that is described as a "synchronous telegraph." (images)
 
-330
Aristotle first describes image projection in terms of the camera obscura concept.  As eventually applied, the concept is demonstrated in a "darkened box or chamber" with a small hole on one side through which light is admitted.  An inverted image of the scene is projected onto an interior wall, where it can be viewed and traced by an artist. (source-1 and source-2)
-150
Polybius, building on ideas of Cleoxenus and Democleitus, designs a "code book" torch telegraphy (picture; [source]).
- 65
Titus Lucretius Carus - ( 98 - 55 BC ) 'De Rerum Natura' - Book 4 pp. 768 - First reference to persistence of vision
 ..."This ( perception c.f. movement ) is to be explained in the following way; that when the first image passes off, and a second is afterwards produced in another position, the former then seems to have changed its gesture"
also from another source...
 "Titus Lucretius Carus, a Roman poet and philosopher, describes frame sequential animation almost two thousand years before the advent of motion pictures."
BC


AD
 

113:

Roman Legions may have used signal beacons.  See one of a set of three Roman guard houses depicted on Trajan's Column (source-1 and source-2)
130:
From Ptolemy's 'Optica' "...if a sector of a disk be coloured, the whole will appear of that colour when rapidly revolved and if the sector be variously coloured at different distances from the centre, the disk will appear ringed".
180:
Inventor Ting Huan perfects a device, for projecting moving images. Similar inventions are reported in China as early as 207 B.C.
500:
It is said that lantern carrying kites were used as a communication vehicle during the siege of Nanking.  In any case,  very early use of "communication" kites in China is clearly substantiated by the many other instances of sending "red lanterns" aloft and dispatching messages from kite lines. (source)
1030:
Abu 'Ali Al-Hasan Ibn Al-Haitham, or Al-Hazen, writes the text Optical Illusion in which describes the "Camera Obscura" and the "Persistance of Vision."   Al-Hazen's theory is that light carries the reflection of an object to the eye, thus implying the eye's need to focus. These concepts significantly influence the work of Italian Rennaissance painter Brunelleschi, who applies them to his perspective painting.
1437 :
Architect Leon Battista Alberti demonstrates the art of perspective in drawings observed though a pinhole. Alberti is significantly influenced by the painter Brunelleschi, who is credited with the first paintings to manifest the concept of perspective. Alberti honors the artist by translating his perspective geometry into a Latin treatise on the subject that includes classical references, but is still simple enough for any painter or architect to understand.
1481:
Pigeon Post:  a woodcut from 1481 (source)
1550 :
Geronimo Cardano makes the first camera lens.
1553 :
Gemma Frisius constructs a functional "Camera Obscura"
1558 :
Giovanni Battista Della Porta, a physicist and philosopher in Naples publishes the book 'Natural Magic'.The first edition is in four volumes, the second - in 1589 - is in twenty. It will be reprinted more than twenty-seven times. The book discusses methods for exploiting the forces of nature to perform feats of "magic."  The first edition describes the "camera obscura."   Sections of the book deal with magnetism, optics and such topics of contemporary interest as demonology and astrology.  Della Porta also publishes books on meteorology, optics, pneumatics, architecture, astronomy, astrology and mnemonics.
1575 :
An Englishman, Thomas Ruckert, devises an instrument which records compass bearings on a paper tape.
1588:
A system of beacon fires successfully used to mobilize England against the onslaught of the Spanish Armada. (source-1 and source-2)
1600:
William Gilbert  (1544-1603), physician to Elizabeth I  James I of England, publishes the first and, perhaps, most significant treatise on electrical and magnetic phenomena,  De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure ("On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth").   Widely regarded as the founder of electrical science, he seems to be the first person to use the terms electricity, electric force and electric attraction and to suggest a link between static electricity and magnetism.  (source-1)
1604 :
The astronomer Johann Kepler publishes a work on the optical principles involved in the study of astronomy. He explains how the eye focuses light and demonstrates that as light travels from its source, its intensity falls at a rate of the distance squared.
1609:
Galileo Galilei (1564-1642) designs and presents to the Venetian doge Leonardo Donà a 10-power spyglass which is more powerful and of better quality than any telescope yet produced. (source)  The Dutch spectacle maker Hans Lippershey (1570-1619) is usually credited with making telescopes widely known.
1649:
Athansius Kircher, a German Jesuit, constructs his "projector" and publishes Ars Magna Lucis et Umbrae. 
1650:
Otto von Guericke (1602 - 1686) invents the air pump and demonstrates effects of vacuum. (picture; source)
1659:
Christiaan Huygens (1629-1695) constructs a "Magic Lantern."  (source)
1663:
Otto von Guericke develops the first frictional electric machine (picture-1 and picture-2; source-1 and source-2)
1671:
Athansius Kircher publishes a text on the principles of "Persistence of Vision."
1676:
The Danish astronomer Olaus Roemer (1644-1710) establishes that light travels at a finite velocity.
1675:
On his way home from the Paris Observatory one night, French astronomer Jean Picard discovers that the more he shakes his mercury-filled barometer, the more it glows with an unexplainable light. (source)
1678:
Dutch natural philosopher Christiaan Huygens (1629-1695) proposes his wave theory of light in Traite de la lumiere. It is overshadowed by Newton's corpuscular theory, but will finally be recognized in the 19th century. It marks the beginning of physical optics.
1684:
Robert Hooke (1635-1703)  proposes a coded optical telegraph system.  In a lecture entitled On showing a Way How to Communicate One's Mind At Great Distances Hooke describes an optical encoding device. (source) A dubious representation of a synchronized telegraph system. which is based, more or less, on Hooke's encoding scheme. (source).
1702-09:
Francis Hauksbee (c.1666-1713) conducts a brilliant series of seminal experiments.  Hauksbee is probable best known for his experiments with electroluminescence -- i.e. making something glow using electricity.  Of particular importance and enduring value is his invention of a two-cylinder air pump that is a great improvement on von Guericke's 1650 design.  (picture; source-1 and source-2)

In experiments before the Royal Society in 1705, Hauksbee establishes that sound needs a medium to support propagation by demonstrating that a ringing bell in an evacuated glass jar gives off no sound.

Also in 1705, Hauksbee is able to repeatably replicate the glow in mercury first observed by Jean Picard in 1675.  By adding an air valve to a barometer, he is able to demonstrate that the glow is best when the barometer was half-filled with air.  He hypothesizes that friction between the glass and mercury was responsible. Interestingly, the phenomenon is still not completely understood. (source)

In 1706, Hauksbee introduces new, more powerful and reproducible electrostatic generator, his so called influence machine.   It is essentially an improvement on von Guericke's friction electrical machine wherein a glass globe is substituted for von Guericke's sulfur sphere.

Hauksbee describes his extensive experiments in his book Physico-Mechanical Experiments on Various Subjects published 1709.

1704:
Newton's "Optics" is published, detailing his "corpuscular" theory of light. Newton believes light to be a particle phenomenon, and accounts for its occasional wave-like behavior by conceding that the particles may cause vibrations in the ether - a hypothetical substance which, it is assumed, pervades all space.
1720 :
Louis Bertrand Castel invents a "clavecin oculaire" or optical harpsichord. The keys of the instrument move colored tapes over a light source, creating a light show to accompany the music.
1727:
Johann Heinrich Schulze (1684-1744) discovers  the darkening action of light on mixtures of chalk and siver nitrate. (source)
1729:
Stephen Gray (1666-1736) demonstrates that the static charges of electricity can be conducted by some materials (e.g., wet twine) for distances as great as 765 feet while others (e.g., silk thread) do not conduct electricity.  His observations are published in a series of papers in the Philosophical Transactions of the Royal Society from 1731 to 1736. (source-1 and source-2)  (Also see picture of the Electric Boy)
1745:
Ewald Georg von Kleist (1715-1759), the dean of the cathedral at Cammin in Pomerania (Germany), and Pieter van Musschenbroek  (1692-1761),  a professor at the University of Leiden (sometimes spelled Leyden ) in the Netherlands, discover independently that a glass vessel filled with water and charged by a friction source can store the electric charge for later use. The device became known as the Leyden jar.  (source-1 and source-2)
"A glass vial is filled partly with water and stopped with a cork that is pierced with a wire or nail that dips into the water. When the wire is brought into contact with a device that produces static electricity, the jar stores that electricity so it can be used in later experiments." (source)
Somewhat later Sir William Watson (1715-87) and Dr. John Bevis (1693-1771) improved the jar by coating the inside and outside with tin foil.  Shortly after the discovery of the Leyden jar Benjamin Franklin, became the first electrical experimenter to understand and explain how it functioned. Franklin based his understanding on another of his observations that electrical energy has both positive and negative charges. (source)
1748:
In Britain, William Watson describes watching rays of electricity in a tube. Watson is a contemporary of Benjamin Franklin. Together they originate the principle of conservation of charge: the total quantity of electricity in an insulated system is constant.
1752:
Benjamin Franklin proves that lightning is electricity through a series of experiments culminating with the famous 'flying of a kite' during a thunderstorm. In theory ( the actual experiment is more one of folk lore ) the lightning is drawn to the steel-tipped kite and the electricity runs down the kite string to an iron key. The next two people to try this experiment are electrocuted. Following this experiment, Franklin mounts lightning rods on his own home and on two public buildings. The steel-pointed rods draw the lightning away from the buildings and discharge it into the ground. Although he does a great deal to popularize electricity, Franklin laments later that he has done nothing of direct use to mankind.
1753:
 In a letter, dated February 1st and published February 17th, to the Scots' Magazine entitled "An expeditious method for conveying intelligence," the mysterious C.M. (perhaps Charles Morrison or Charles Marshall) proposes the first practical telegraph based on the discharge of static electricity. (source-1 and source-2)
1760:
Tiphaigne de la Roche predicts photography in Giphantie.
1765:
Abbe Nollet wrote in his Lecons de Physique..."When an object moves very rapidly before our eyes, we often attribute to it size and shape which it does not possess".
1770:
John Cuthbertson, an English instrument maker living in Amsterdam, makes an electric battery out of 135 Leyden jars.
1774:
An electrostatic telegraph is demonstrated in Geneva, Switzerland by George Louis Lesage.  He built a device composed of 24 wires separated from each other by insulators.  At the end of the wire was a pith ball which was repelled when a current was initiated on that particular wire. Each wire stood for a different letter of the alphabet. When a particular pith ball moves, it represents the transmission of the corresponding letter. (picture)
1775:
Count Alessandro Volta, physicist and Professor of Natural Philosophy at Pavia, Italy, invents the 'Electrophorus', a device that produces static electricity by friction.
1781:
Painter and set designer Philippe Jacques de Loutherbourg creates a device he calls the Eidophusikon. This uses moving pictures to represent natural phenomena. Loutherbourg, who is known for his collaboration with the actor and manager David Garrick, exhibits his invention in London.
1784:
Charles Augustin de Coulomb (1736-1806) invents the torsion balance for measuring the force of magnetic and electrical attraction. With this invention, Coulomb is able to formulate the principle, to become known as Coulomb's law, governing the interaction between electric charges.

From the court at Versailles, Seraphin's famous 'Chinese Shadow Theatre' transferred to the Palais Royale and captivated Paris as a public attraction

1786:
Gilles-Louis Chrétien develops the 'Physionotrace' for profile portraits
1788:
An Irish painter, Robert Barker, paints a panorama, a 360° view of Edinburgh, around the wall of a circular building.
1788-91:
Luigi Galvani (1737-98) develops a theory of "animal electricity" or, as it comes to be called, 'Galvanic Electricity', after observing that a salinated dead frog lying on a zinc surface twitches when touched with a scalpel. These findings will lead to the invention of the 'Voltaic Pile', the world's first battery. (source)
1792:
Claude Chappe (1763-1805), a mechanic, and Abraham Louis Breguet, a watchmaker, are the first to construct a functioning semaphore (T-type moving arms) optical telegraph  machine. After a successful demonstration of the machine before representatives of the National Convention on July 12, 1793, the Chappe Telegraph Line will be established between Paris and Lille in 1794. In the wake of the French Revolution, the optical telegraph was to acquire great military importance.  The optical semaphore telegraph system will eventually covered France with a total of 556 stations spanning 4800 KM. (source)
1794:
Robert Barker opens the first 'Panorama', a prototype of future movie houses

Volta finds elecricity is generated by different metals

1798:
Belgian physicist Etienne Gaspard Robert professionally known as 'Robertson' develops the 'Fantasmagorie'
1800:
Inspired by Luigi Galvani's discovery of animal electricity in 1786, Alessandro Volta (1745-1827), professor of natural philosophy at Pavia, discerns that Galvani induced a twitch in a frog's leg by using dissimilar metals in his experiment. Volta then groups sheets of zinc and copper in acid to produce a continuous flow of electricity. He calls it a 'continuous current pile', and the marketed version - the "Voltaic Pile."  (source-1, source-2, source-3; picture)
Sir William Herschel, a British astronomer (born in Germany), discovers (the existence of infrared rays) the infrared region of the spectrum of light.

Inauguration of the first U.S. optical sema-phore/telegraph system between Martha's Vineyard and Boston.

1801:
Depillon, a former artillery officer in the French Army, develops a semaphore system for a signal machine with three or four arms. This system has a vocabulary of 301 signals. Depillon's machines are installed all along the French coastline to signal ships at sea.

Cambridge scientist Thomas Young formulates the wave theory of light.

1802:
Thomas Wedgewood, following experiments of Schulze and Scheele, produces silhouettes by use of siver nitrate but is unable to fix the images
1807:
Dr. William Hyde Wollaston, the London chemist and physicist, invents the 'Camera Lucida'. This is an optical device that projects the virtual image of an object onto a screen.
1808:
Humfrey Davy produces the first electric arc light


1808-10:

A complex telegraphic system, based on an electrochemical current, is designed and demonstrated before he Munich Academy of Science by S.T. von Sommering (or von Soemmerring) (1755-1830).  Commissioned by Margrave Leopold of Bavaria, an ally of Napoleon, the electrolytic telegraph consisting thirty-five wires, one for each letter of the alphabet and one for each number. At the transmitting end of his system, arrangements are provided for passing currents from a "voltanic pile" through any one of the signal wires.  At the receiving end each wire is connected to one of a series of thirty-five electrodes that are immersed in an acid bath. Completion the circuit caused the evolution of bubbles of hydrogen at the electrode corresponds to a particular letter or a number. (picture)
1816:
A French inventor, Joseph Nicephore Niepce, produces the first photograph through a process he calls heliography or sun drawing. Niepce's process uses an instrument like the camera obscura to record an image on paper coated with silver chloride. The image is only temporary, however. It will be another six years before Niepce is able to capture images permanently.

Joseph Henry proposes a single wire telegraph. Sir Francis Ronalds demonstrates such a device in 1816, in his garden at Hammersmith. Others do not share his vision, though, and his ideas, published in 1823, go largely ignored. In the words of the British Admiralty, to whom Ronalds has offered his invention, "Telegraphs of any kind are wholly unnecessary..."

Admiral Sir Home Riggs Popham tests a semaphore telegraph, mounting the semaphores on ships in the English Channel. The trial run takes place sixteen years after the initial invention of the Popham system. It is a success, the Admiral receives £2000, and lines are thereafter established between Whitehall, Portsmouth, Plymouth, Chatham and Dover.

1817:
Swedish Baron Jons Berzelius isolates the element selenium and shows that its electric conductivity reacts to light.
1819-20:
Hans Christian Oersted (1777- l851), professor of physics at the University of
Copenhagen, discovers the link between electricity and magnetism during a lecture he gives at Kiel University. A wire from the galvanic battery he is using accidentally falls on a compass, whose needle is thus deflected from the Polar North position. Inadvertently, he gives the first demonstration of electromagnetic induction. His discovery will lead to William Sturgeon's development of the electromagnet.
1820:
Davy shows that electric current forms a magnetic sheath around the wire

Ampere formulates the right-hand rule

John Herschel discovers the photographic fixative, hyposulfite of soda.

James Bowman Lindsay conduced experiments in communication utilizing the conductive properties of water.

1821:
A theater for the display of large panoramas is designed by showman and scene painter Louis Jacques Mande Daguerre. Known as the Diorama, its effects are enhanced by dramatic lighting. (In 1824 Daguerre will attempt to capture and preserve the images of the camera obscura, unaware that Nicephore Niepce has already accomplished this goal. In 1826, Daguerre will become aware of Niepce's work and begin corresponding with him. In 1829, after Daguerre overcomes Niepce's initial reluctance, they will become partners.)

Schweigger invents the galvanometer.

1822:
Seebeck discovers thermoelectricity
1823:
In England, Sir Francis Ronalds builds a 'telegraph' in his garden; no one is interested.
1824:
William Sturgeon creates a practical application for magnetism with the electromagnet. He discovers that by running an electric current through a coil of copper wire wrapped around a soft piece of iron, a magnetic field is produced. This discovery lays one of the cornerstones for Bell's invention of the telephone.

Physicist Andre-Marie Ampere demonstrates the galvanometer at the National Institute of Paris, a device that uses a freely moving needle to measure electric current. The unit of electricity known as the ampere or "amp," is named after him.

Peter Mark Roget discovers ability of retina to retain image for 1/20 - 1/5 of a second - demonstrates the persistence of vision with his 'Thaumatrope'

1825:
André-Marie Ampère establishes mathematical basis for electrodynamics

An English doctor, John Ayrton Paris, invents the 'Thaumatrope', an optical parlor toy that exploits the phenomenon of persistence of vision. A small piece of cardboard with a different picture on either side is rotated quickly. As one image replaces the other, the eye combines the two pictures into one. Paris had based his idea on work by the astronomer Herschel and William Fritton.  Thaumatropes are also referred to as 'Magic Disks'

1826:
Joseph Nicéphore Niépce uses Bitumen of Judea for photographs on metal
1827:
What is now known as Ohm's law appears in Die galvanische Kette, mathematisch bearbeitet. Between 1825-27, Georg Simon Ohm (1789-1854), professor of mathematics at the Jesuit College of Cologne, had been studying electrical conduction following as a model Fourier's study of heat conduction.   Ohm's Law states that the strength of an unvarying electric current is directly proportional to the electromotive force, and inversely proportional to the resistance of the circuit concerned. Need it be said, the unit of resistance is named after him. (source 1 and source 2)

The visionary English inventor Charles Wheatstone, increasingly intrigued by the transmission and amplification of sound and voice, designs a microphone. Wheatstone's work in acoustics will win him a professorship of experimental physics at King's College in London in 1934. It is here that he will conduct his groundbreaking experiments in electricity.

1829:
Niépce and Louis Jacques Mandé Daguerre form a 10 year partnership to develop photography

Belgian physicist Joseph Plateau invents a parlor toy, the 'Phenakistoscope'. A series of drawings showing successive stages of a continuous motion are displayed on a spinning disc. When the drawings are seen one at a time through a small opening, an illusion of motion is created.This is considered the first motion picture device.

1830:
Joseph Henry discovers phenomenon of electrical self inductance. The unit of inductance known as the 'henry' is named after him

Michael Faraday passes electricity through vacuum tube.

1831:
The Englishman Michael Faraday and the American Joseph Henry independently discover the phenomenon of electromagnetic induction. (However, Henry discovered the properties of mutual- and self-induction) In independent experiments, Faraday and Henry observe that an electric current is induced in a closed coil of wire when a magnet is passed through it.
Henry, a teacher of mathematics in Albany, New York, demonstrates his findings with a bell that rings when stimulated by an electrical impulse.

Faraday, the son of an English blacksmith and Professor of Chemistry at the Royal Institute in London, discovers electromagnetic induction using an electromagnet. He is credited with building the first electrical transformer, and his findings lead directly to the development of electrical machinery for industry.

Faraday proposes a single wire telegraph based on this discovery. The work of both men will inspire Samuel Morse to develop the telegraphic receiver. Further, it will play a significant role in Bell's invention of the telephone.


In Paris, physicist Antoine Cesar Becquerel investigates electromagnetic balance.

1832:
Charles Wheatstone invents a non-photographic 'stereoscopic viewing device' ( This is also reported as far ahead as 1838 ? )

Belgian physicist Joseph Plateau invents a parlor toy - the Phenakistoscope. A series of drawings showing successive stages of a continuous motion are displayed on a spinning disc. When the drawings are seen one at a time through a small opening, an illusion of motion is created. This is considered the first motion picture device. It is marketed as the 'Phantascope' ( also called in England the 'Fantascope' ) Plateau loses his eyesight by conducting too many experiments on his own retinae.

The Wheel of Life, or Daedalum, an optical toy, is introduced by W.H. Horner. Thirty years later, the device will be patented in the US by the Milton Bradley toy company.

Simon Von Stampfer invents the stroboscope, ( a phenakistiscope in reverse ) which casts regular flashes of light on moving objects - making their motions appear jerky and abrupt.

William Henry Fox Talbot begins experiments with photogenic drawings

On a visit to Berlin, Tsar Nicholas 1 saw a demonstration of the first telegraph system which did not need a wire for each letter. It was developed by a Russian diplomat, Baron Schilling, based on Oersted's electromagnetic ideas and German inventor Samuel Thomas von Sömmering's early experiments. Signals were sent along between one and six wires, causing movement in compass needles, suspended over coils, which indicated the letters.

Carl Friedrich Gauss, the mathematician, physicist and astronomer, constructs the first electric telegraph, assisted by physics professor Wilhelm Eduard Weber.

Scientist S.H. Christie invents an electrical bridge circuit for measuring the value of a resistance. Though created by Christie, the device is named for Sir Charles Wheatstone, who popularizes its use ten years later.

1834:
William George Horner patents the 'Daedelum' - The wheel of the Devil. Later ( around 1864 ) French inventor Pierre Desvignes refines the device and markets it under the name 'Zoetrope' - The Wheel of Life.
The device consists of a drum with equally spaced vertical slits ( peepholes ) down the side and a series of images on strip of paper ( showing a figure or object in graduating stages of motion ) laid flat against the inside surface below the line of slits. As the drum spins and the viewer looks through the slits at the strip of spinning images ( faster than 12 images per second ), the individual frames merge into one sequence and the figure or object appears to move.

This truly was the beginning of what we now call cinema - a series of sequential images presented to the eye at such a rate that the so called persistence of vision convinces us that the images are indeed one continuous motion. Equally the Zoetrope introduced the concept of 'scanning' or breaking down an image into small fragments to be re assembled either in the brain 'on site' or at a distant point by converting the segments into electrical signals which themselves can be reassembled to recreate the original scanned image.


In Scotland, James Bowman Lindsay, an inventor and scientist without formal education, uses galvanic cells to produce continuous electric light.

1835:
P. C. Munck af Rosenschöld (Sweden) observes that resistance of powdered conductors is drastically reduce by high voltage discharges.
1836:
A constant electrical current is achieved by John Frederick Daniell, a chemistry professor in London, when he introduces a non-polarizing battery: the Daniell Cell.
1837:
Together with William F. Cooke, Sir Charles Wheatstone, a physicist and inventor, patent an electric telegraph in England on July 10. Their telegraph, an improved version of the Schilling electric telegraph, ( just ) predates Samuel Morse's device. The first test of their system is conducted in a transmission spanning the 1.2 miles between Euston and Camden. When it is perfected, they will offer their telegraph to the British Railroad System.
Working with student Alfred Lewis Vail, whose father owns a small electromechanical factory, American painter Samuel F.B. Morse develops and patents ( September 28 ) a working electric telegraph. Morse first conceives his system of electromagnetic communication while returning by ship from studying art in Europe. In the course of his journey, he is inspired by a conversation regarding the newly discovered electromagnet.
 
Electrical telegraphic systems have already been worked on by other inventors, most notably Sir Charles Wheatstone. It is Morse, however, who makes the significant addition of the electromagnet upon which his receiver is based.
Louis Daguerre invents 'Daguerreotype' cutting exposure time down to 20 minutes
1838:
K.A. Steinheil of Munich shows that one of two wires used in overland telegraphy could be dispensed with by using an earth ground. He looked forward to a time that the second wire could also be eliminated, and 'wireless' telegraphy could be used.

Samuel F.B. Morse's telegraph is augmented in 1838 by a system of dots and dashes he devises, representing numbers and letters of the alphabet. Known as the Morse Code, this signalling strategy is used to communicate complete messages which can be listened to or read on a printed tape as they are transmitted across the telegraphic wire by electrical pulses of varied lengths. Visual signals, such as flashing lights, can also be used to transmit coded messages.

Physicist Sir Charles Wheatstone invents an optical viewing device, the stereoscope. With the aid of strategically placed mirrors, two slightly different pictures converge when seen through the apparatus, thereby giving a sense of depth to the image. In 1849, David Brewster will improve the stereoscope and the twin camera, enhancing the three dimensional realism when pictures are viewed.

1839:
Antoine César Becquerel examines electrochemical effect of light.

The Daguerreotype is publicly announced at the Academy of Sciences in Paris and given to the world

Hippolyte Bayard produces direct-positive images on sensitized paper

1840:
Alexander Walcott issued first American patent in photography for his camera

The Austrian optician Joseph Petzval introduces the f 3.6 Petzval photographic lens. Designed to diffuse 16 times more light than the field lens, it is perfectly suited for portrait photography.

1841:
William Henry Fox Talbot patents the Calotype process
1842:
Alexander Bain proposes facsimile telegraph transmission that scans metal letters and reproduces image by contact with chemical paper. Synchronized scanning is part of proposed transmission system.

Joseph Henry first produced high-frequency electric oscillations and discovered that a condenser (Leyden Jar) discharge is oscillatory.

Samuel Morse, artist and pioneer of the electric telegraph in America, directs the construction of an underwater telegraphic cable that is laid between the Battery and Governor's Island in New York.

1843:
Alexander Bain, patents his 'pantelegraph', an electrical method for transmitting images over a distance. This facsimile system can be said to be a primitive forerunner of television. In Bain's system of two synchronous pendulums with styluses attached, the movement of one stylus is communicated to the other, using nonconducting ink on conductive paper on the one end, and sensitive paper on the other. Although the system looks good on paper, it proves to be somewhat unreliable, since the pendulums are not truly synchronized as they should be. Others improve on Bain's invention in the years to come.

Charles Wheatstone devises the rheotstat, a variable resistor designed to regulate electrical current. He uses it in experiments with the Wheatstone Bridge, an electrical circuit invented by S.H. Christie to measure the value of a resistance. It is named for Wheatstone though, as he is the first to put it to extensive and significant use.

1844 :
It has taken Samuel Morse several years of perseverance to talk Congress out of the $30,000 needed for the experimental telegraph line between Washington and Baltimore. The decision is made with a narrow margin, and the line is completed. Morse's dot and dash code makes the single wire telegraph practical. Public usage is inaugurated on the Baltimore-Washington telegraph line in 1844 when Morse transmits the first message, "What hath God wrought!" through coded interruptions of an electric current. The dots and dashes can be heard or recorded on paper tape. The telegraph spawns signals communication, and the analysis thereof, called "signals intelligence" (SIGINT).

Arc lights are used in the Paris Opera House

1846:
Faraday suggests that light and electricity may be different manifestations of the same force.

The Electric Telegraph Company is established by William Fothergill Cooke who, with Sir Charles Wheatstone, devised an electric telegraph nine years ago. Within a year, two networks will have been established: one in the north, linking major cities from Edinburgh to Birmingham, the other in the south, linking London, Dover and Southhampton. In a six year period after its founding, the company will lay 4000 miles of telegraph wire.

J.E. Fuller combines his personally designed time telegraph with the Fuller circular slide rule to create a computing telegraph.
1847:
Frederick Bakewell improves on Bain's idea by using tin-foil covered revolving drums ( for transmitting and receiving recorded pictures )
1848:
Claude Felix Abel Niépce de Saint-Victor uses albumen on glass plates for negatives
A Hampstead engineer named Francis Whishaw creates a "speaking telegraph." The device, known as the telekouphonon, serves as a sort of intercom for long-distance communications in dockyards or large firms. The telekouphonon's cable is made of gutta-percha, caoutchouc, glass or earthenware, and connects with an ivory, bone, wood or metal mouthpiece.

The telegraph now links New York and Chicago.

1849:
The Continental Telegraphen Compagnie of Berlin, also known as the Wolff Agency, is the first telegraph news service. Like the Agence Havas of Paris, founded in 1835, and the Reuter Telegram Company of London - Reuters - founded in 1851, the Wolff Agency begins as a service providing financial information to bankers but soon offers world news to newspapers and other periodicals.

Engineer Antonio Meucci develops and tests an experimental telephone while working in Havana.

1850:
Albumen printing paper introduced by L. D. Blanquart-Evrard

Fizeau measures the velocity of electricity

The brothers W. and F. Langenheim of Philadelphia produce the first photographic lantern slides, used to project narrative sequences. These were the immediate forerunners of narrative films.

1851:
Frederick Scott Archer publishes wet-collodion process

William Henry Fox Talbot makes first instantaneous photographs using electric spark illumination

Morse Code is adopted and modified by a special conference of European nations to produce a simpler and more precise system. Known as International Morse Code or Continental Code, it replaces spaced letters with unspaced letters. Moreover, the Continental Code uses dashes of uniform length, as opposed to the original Morse system which used three different lengths. International Morse code is still used today for ship-to-shore communications and amateur radio.

Louis Jules Duboscq designs a stereoscopic still camera, based on the concepts developed two years earlier by Sir David Brewster in England. The camera produces right and left monocular photographs that appear three-dimensional when viewed through a stereoscope.

1852:
The theory of fluorescence is developed and introduced by George Gabriel Stokes, a professor of physics and mathematics and Fellow of Pembroke College, Cambridge.

William Henry Fox Talbot patents a prototype of photo-engraphing

In 1852, there are 6500 km of telegraph wire strung in England. By 1862, the number is up to 24,000 km.

1853:
Duplex telegraphy is explored by Dr. Wilhelm Julius Gintl, allowing simultaneous transmission of signals in opposite directions. Moses Gerrish Farmer of Massachusetts pioneers multiplex telegraphy, a system which increases the capacity of a telegraph line, allowing up to six operators to share it. The system is perfected by Emile Baudot in 1874.
1854:
The telegraph is used in Crimean War

French engineer Charles Bourseul, an expert in telegraphy, experiments with ideas for a kind of telephone.

A telegraph that prints letters of the alphabet is suggested by the designs of David Edward Hughes, an English music professor living in Kentucky.

Cyrus Field invites a syndicate of ten capitalists to to join an venture team to undertake the laying of a transatlantic cable.  The enterprise organized as the New York,
Newfoundland and London Telegraph Company.  The most important feature of this newly chartered company was its exclusive cable landing rights in Newfoundland and
Labrador for the next fifty years!

1855:
German inventor Heinrich Geissler develops mercury pump and produces the first good vacuum tubes.
1856:
Celluloid is synthesized by British chemist Alexander Parkes, under the name "parkesine." Parks will form The Parkesine Company, Ltd. ten years later, but it will last only two years. The synthetic plastic material he creates as a prototype for celluloid will be developed as a commercial product by John Wesley Hyatt in 1869.
1857:
Painter Leon Scott de Martinville designs the phonautograph, a precursor of the phonograph. His device makes permanent visual records of sound waves, which can then be analyzed. Alexander Graham Bell observes the phonautograph at the Massachussets Institute of Technology in 1874.

Kirchhoff relates static and current electricity by the constant velocity 'c'

German scientist Hermann von Helmholtz notices that he can make the strings in his piano vibrate when he sings into it. He then causes a tuning fork to vibrate and produce sound by switching an electromagnet on and off. This principle is the basis of the audio speaker, and sets one of the cornerstones of the invention of the telephone by Alexander Graham Bell.

1858:
Heinrich Geissler, a German glass blower and maker of scientific instruments creates the Geissler tube. A vacuum is created in a glass container sealed with electrodes at either end. Electrons moving through the tube are visible as patterns of light, varying according to the shape of the tube or the type of gas introduced into the vacuum. This invention will lead to the discovery of cathode rays, a basic principle of video technology.

Julius Plücker shows that cathode rays bend under the influence of a magnet suggesting that they are connected in some way.

The first trans-Atlantic telegraph cable is laid and operates for only four weeks.

Photographer Thomas Skaife builds the Pistolgraph, a novelty snapshot camera that almost gets him arrested when he aims it at Queen Victoria.

1859:
Establishing an important principle for the future of electronics, the German mathematician and physicist Julius Plucker discovers that cathode rays ( electrons ) are deflected by a magnetic field.

Alexandre Edmond Becquerel, a member of the noted family of French physicists, uses a Geissler discharge tube filled with fluorescent material to create the first primitive fluorescent lamp.

Thomas Sutton, an editor of the English publication "Photographic Notes," is the first to develop a panoramic liquid lens, more commonly known as the wide angle photographic lens.

Thomas Du Mont patents his 'camera zootropica', capable of reproducing the phases of movement in 12 successive images

Johann Wilhelm Ritter's discovery of the secondary cell, almost 60 years earlier, forms the foundation for the Frenchman Gaston Plante's invention of the first electric storage cell: the lead-acid storage battery.

1861:
James Clerk Maxwell's On the Theory of the Three Primary Colours

Oliver Wendell Holmes invents the popular 'stereoscope viewer'

American inventor Coleman Sellers patents the 'Kinematoscope': posed photographs mounted on a turning paddlewheel. In picture parlors, the Kinematoscope crudely projected the photographs for the audience by flashing them rapidly on a screen.

Developed by Philadelphia Coleman Sellers, this antecedent of the cinema consisted of a series of stereoscopic pictures printed on glass plates which were strung together by chain mounted in a box. The spectator turned a crank and saw moving images.
The Kinematoscope, a device that takes stereoscopic photographs, is invented in Philadelphia by Coleman Sellers. Like David Brewster's double camera, the device simultaneously takes two pictures of the same subject, but at slightly different perspectives. This gives the resulting photographs a suggestion of depth and dimension when they are observed through a special viewing device.
 
NB: The above "kinematoscopes" is obviously incorrectly named as the descriptions of operation seems to represent a distinctly different device to the two above - to be researched.
Western Union completes construction of a transcontinental telegraph line. This line, which links New York and San Francisco, has been completed despite interference by hostile Indians and Confederate guerrillas.

German schoolteacher Johann Philipp Reis ( 1834-74 ) suceeds in transmitting speech and music electrically down a wire using a device he called das Telephon - the 'telephone.' These come in various shapes and sizes; one resembles a large wooden ear. Reis' devices are fragile and clumsy laboratory models, never put to public use, and are sold only to research labs or other experimenters.

1862:
In 1852, there are 6500 km of telegraph wire strung in England. By 1862, the number is up to 24,000 km. Signalling distances have been improved with the introduction of an electromagnetic receiver that supplements the line current with the use of local battery power, thereby "lengthening" the line. Italian physicist, Abbe Giovanni Caselli, is the first to send fixed images over a long distance, using a ( wired ) system he calls the 'pantelegraph'.

Maxwell, "On Physical Lines of Force"

1863:
Using the work of civil engineer Henry Dircks as a foundation, analytical chemist John Henry Pepper creates a machine that uses mirrors and lenses to project a ghostly image. 'Pepper's Ghost' is demonstrated at London's Royal Polytechnic Institute.
1864:
James C. Maxwell theorized, in the paper entitled "A Dynamic Theory of the Electromagnetic Field," to the effect that electrical disturbances should travel at light speed.  The Maxwell's Equations are an extension and mathematical formulation of Faraday's theories of electricity and magnetic lines of force.

In Virginia, USA, wireless electromagnetic waves are transmitted 14 miles

Joseph Wilson Swan perfects the carbon process

Around this time French inventor Pierre Desvignes refines William George Horner's 'Daedelum' and markets it under the name 'Zoetrope' - The Wheel of Life. Toy magnate Milton Bradley packages a study drum, rotation device and supply of animations sold for $2.50

1865:
Mahlon Loomis transmits wireless telegraph messages between two mountains in Virginia.  Loomis used two kites flown18 miles apart, each carrying a wire that reached to the ground. When he interrupted the flow of electricity from the atmosphere, through the wire, to an earth ground, a galvanometer on the other kites wire measured a change in current. He obtained a patent for this system in 1872, but never obtained financial backing to develop his idea.

Atlantic cable ties Europe and U.S. for instant communication

1866:
 Cyrus Field has eventual success with a Transatlantic Cable from Ireland to Newfoundland.

Varley brothers (England) patented a lightning surge protector based on Munck's observation that the resistance of powdered carbon is drastically reduce by high voltage discharges.

The 'Woodburytype' process is patented

American dentist Mahlon Loomis ( 1826-1886 ) uses radio waves to send telegraph messages between two mountains in West Virginia - a distance of 22.5km - using aerials held in the air by kites.

Western Union Telegraph acquires two other telegraph companies and becomes the first great industrial monopoly in the US.

French physicist Antoine Becquerel develops the first fluorescent lamp. It uses a mercury arc and a fluorescent phosphor coating to provide an extremely efficient light source.  Becquerel is the grandfather of Henri Becquerel, the discoverer of radioactivity.

1867:
Professor Charles Wheatstone, a key contributor to the development of the English telegraph, creates the first automatic printing telegraph system. Messages are typed on an instrument like a typewriter, and automatically coded and transmitted as a series of pulses.

Siemens invents the modern dynamo

1868:
Amos Dolbear while a professor at Bethany College invented the 'electrostatic telephone'. Dolbear also work on converting sound waves into electrical impulses.

 The forerunner of today's dry cell battery is developed by French chemist Georges Leclanche. The cell is assembled inside a glass jar and generates about 1.5 volts.

1869:
Louis Ducos du Hauron's 'Colors in Photography' describes the principles of color photography using the subtractive method

Basing independent experiments on Young and Helmholtz' theories of color separation and mixing, France's Charles Cros and Louis Ducos du Hauron both develop a subtractive method of color photography. Three different color positives representing cyan, magenta and blue respectively are superimposed on one another to create the final picture. These colors are described as subtractive primaries because they each represent the remaining color after one primary color has been subtracted from white light.

Communications entrepeneur Cyrus Field completes construction of a telegraph cable connecting the US to continental Europe for the first time. The cable runs from France to Duxbury, Massachusetts.
 

1871:
Richard Leach Maddox invents the 'gelatin dry plate silver bromide' process
1872:
John W. Hyatt begins manufacturing 'celluloid'

Eadweard Muybridge started his photographic compilation of animals in motion

Léon Vidal combines chromolithography with Woodburytype printing

U.S. patent (entitled an 'Improvement in Telegraphy') granted to Mahlon Loomis for a wireless (probably induction) telegraph on July 20 (or 30), 1872.

Anson Stager, Enos Barton and Elisha Gray found the Western Electric Company. Their main business is selling telegraph equipment, but Gray is experimenting with the electrical transmission of actual sound - the telephone.

Australia completes its first telegraph network; soon it will be linked to to Indonesia, India and Europe.

1873 :
Maxwell publishes a text on electricity, magnetism and theory of radio waves

Two English telegraph engineers, Joseph May and Willoughby Smith, note that the electrical conductivity of the element selenium changes when light falls on it. This property, called photoconductivity, will give inventors a way of transforming images into electrical signals.

May uses selenium to send a signal through the Atlantic cable
Hermann Wilhelm Vogel increases the spectral sensitivity of photographic emulsions by adding dyes

First color photographs

A daguerreotype disk is devised at the Astrophysical Observatory at Meudon, France by Pierre Jules Cesar Janssen, to photograph the movement of the stars.
 

1874:
Karl Ferdinand Braun (1850-1918) discovers unilateral or "one way" conduction (rectification) at metal wire contacts on metal (lead) sulfide (galena) crystals.
The Irish physicist George Johnstone Stoney (1826-1911) hypothesizes the existence of an "electrine" as  the "atom of electricity" and estimates its charge to be about 10-20 coulomb (close to the modern value of 1.6021892 x 10-19 coulomb).  He actually applies the term "electron" in a 1891 paper in the Scientific Transactions of the Royal Dublin Society. 

The Logograph, built by W.H. Barlow, creates a graphic representation of the sound vibrations produced by speech.

Quadruplex telegraphy, introduced by Thomas Alva Edison, allows the transmission of two messages simultaneously in both directions, producing a total of four messages being transmitted at the same time.

1875 :
Werner Siemens shows that electricity travels along a wire with a velocity approximately equal to that of light.
George Carey builds a rudimentary facimile system using dozens of tiny light-sensitive selenium cells.
1876 :
Alexander Graham Bell invents the "telephone"

The radiometer, an instrument used to detect the effect of light radiation, is invented by Sir William Crookes.

The first Teletypewriter is used on Telegraph lines.

1877:
Thomas A. Edison records sound on cylinders. The first recording - "Mary had a little lamb."

Working independently, E.W. Siemens in Germany and the team of Cuttris and Redding in the U.S. develop the dynamic microphone. In this device, the diaphragm is attached to a light coil that generates voltage through electromagnetic induction as it moves back and forth between the poles of a permanent magnet

Alexander Graham Bell and his father-in-law, Gardiner Hubbard, found the Bell Telephone Association. Western Union establishes the American Speaking-Telephone Co. to compete with them, but the Bell company is already leasing telephones at the rate of 1000 a month. The first telephone switchboard is installed at the office of a burglar alarm company in Boston. Local telephone exchanges go into business in New England, Iowa, and the Great Lakes region. Emile Berliner, a German-American inventor, develops a loose-contact telephone transmitter superior to Bell's. The following year, Bell buys the rights to the invention. By that time, Berliner is patenting an induction coil for use as a transmitter.

(?)The 'radiometer', an instrument used to detect the effect of light radiation, is invented by William Crookes.

English-American photographer Eadweard Muybridge used a battery of 24 cameras to record the cycle of motion of a running horse for Leland Stanford.

Chemist and railway engineer Georges Leclanche introduces the solid depolarizer battery, after ten years of development. Although it is not portable, it is popularly used to power telephones and doorbells for many years. Today's dry cell battery is derived directly from Leclanche's model.

1878:
Sir William Crookes develops the 'cathode ray' tube that confirms the existence of cathode rays.

Maurice Senlacq proposes the use of selenium in facsimile machines to transmit paper documents.

Eadweard Muybridge publishes 'The Horse in motion' He goes on to invent the 'Zoogyroscope' (projector) which in turn became the 'Zoopraxograph' and then the Zoopraxiscope, a sensation at the World's Columbian Exposition of 1893 in Chicago.

In France, Emile Reynaud invents the the 'Praxinoscope', an optical toy and the first practical device for projecting successive images on a screen

1879 :
The Berlin Academy of Sciences offers a prize to the scientist who can show experimentally that a changing electric field generates a transient electric field, and vice-versa.  The challenge is taken up by, among others...Heinrich Hertz.

In Ireland, Denis Redmond builds ( possibly in 1879 ) his 'Electric Telescope' transmitting an image electrically. Argueably the first 'television' system

American, George Carey transmits pictures over wire bundles

Carlo Peresino suggests the concept of television 'scanning'. This is the practice of breaking down an image into picture elements which are then reassembled on the screen of the television receiver.  In the 1880s the idea is seconded by W. E. Sawyer and Maurice Leblanc.

Following his photographic series of a horse in motion, commissioned by Leland Stanford to settle a bet, English photographer Eadweard (that's the way he spells it!) Muybridge develops the zoopraxiscope. The device reconstructs motion from series of photographs on a revolving transparent glass disc, and foreshadows the onset of motion pictures.

American engineer Leroy B. Firman invents the multiple switchboard, capable of handling more than the fifty telephone lines previous switchboards were limited to. The subsequent improvement in service will help to quadruple the number of telephones in service in the US in the next ten years. In 1884 the Western Electric Company will introduce the multiple switchboard to England.

On October 21, 1879, inventor Thomas Edison demonstrates the carbon filament light bulb, making good his bold promise to solve the problem of the incandescence that had been plaguing scientists for 50 years. The lamp glows for 40 hours, powered by a special high-voltage dynamo. The key to Edison's success is the filament material that is housed inside the vacuum bulb: carbonized cotton thread, which demonstrates a greater resistance than platinum wire, the material used formerly. Edison constructs a parallel circuit of 30 lamps, supplied with current from a special high-voltage dynamo. Each of the lamps operates independently from the others, so that one can be turned down without effecting the operation of the rest. Within three years, the Pearl Street central power station in downtown New York City is constructed, the first of many such large-scale operations that light the cities of the world. The Pearl Street plant is equipped with steam-driven generators of 900 hp, which can provide enough power for 7,200 lamps.1875

Anglo-American inventor David Edward Hughs demonstrated the reception of radio signals from a spark transmitter located some hundreds of meters away.  In these experiments, he conducted a current from a voltaic cell through a glass tube filled loosely with zinc and silver fillings, which "cohered" when radio waves impinged on it.

1880:
Maurice Leblanc suggests 'photoelectric scanning' or transmitting a picture in segments also offers the first proposal for color television.

An early scanning device was developed by George Carey. The image was scanned by a selenium cell which travelled across the image in a spiral path. The signal currents were transmitted through a single line wire. The system lacked any synchronisation between scanning transmission and reception.

Denis Redmond publishes the first book about television, 'La Telescopie Electrique' ( The Electric Telescope ).

Piped-in music, transmitted by a device known as the electrophone, telharmonium or dynamophone, is introduced by Dr. Thaddeus Cahill. The system allows subscribers to dial in to a central switchboard in order to receive transmissions of musical and theatrical performances from concert halls and theaters.

U.S. patent granted for a mirror-optical telephone that transmits speech by light rays, called the "photophone" (later rechristened the "radiophone") designed by Alexander Graham Bell and Sumner Tainter.  A further patent covering fundamental improvements to this invention was granted to the American Bell Company in 1897.  A forerunner of today's fiber optic communications, Bell considered the lightwave system for sending sound to be his greatest invention, although it had no practical application at the time.

1881:
The 'Scanning Phototelegraph' is invented by physicist Shelford Bidwell. The process uses electricity and selenium to transmit the image of a chart, map or photograph over a distance, producing a wirephoto. The telautograph, an electrical device used to transmit handwriting and line drawing, is invented by Elisha Gray.

 French inventor Clément Ader builds an ultra-sensitive microphone and, with it, discovers the stereo effect. He uses twelve of these microphones to transmit the sounds of the Paris Opera, via lines laid through the Paris sewers, to the Exhibition Hall at the Palais de l'Industrie. Up to 48 listeners can hear the opera using two receivers each, one for each ear. * Ader called his system the 'Theatrephone'. This is the first public broadcast entertainment.

Feedback:

 Date: Wed, 04 Mar 1998 18:15:05 +0100
From: Eole 
Reply-To: ogechter@club-internet.fr
To: russelln@netspace.net.au
Subject: Clement Ader's phone.

 Hello,

 I'm the author of the Clement Ader's homepage.

 Ader discovered the stereo effect with his theatrophone and not with his microphone.

 If you want more information and pictures on Ader's phone visit my site: http://village.cyberbrain.com/musee/Eole/autresin.htm ( use an automatic translator:the english site isn't ready ) and for the Théatrophone: http://www.telemuseum.se/historia/teatrophon/theatro2.html

 Amicalement
Olivier

 Russell Naughton answers: Yes, Ader's system was indeed called the Theatrephone as I have added now * ( March 98 ). The original data was taken from the excellent Arthur C. Clark site. The discovery of the stated 'stereo effect' was however due to Ader's use of more than one microphone and the subsequent delivery of a number of phase different signals to the listeners ears. In reality, the overall sound would have, without implementation ( or knowlege? ) of the correct phase relationship required by the use of multiple microphones, been quite 'muddy' but none the less acoustically 'diffuse' and somewhat 'stereophonic' in nature.

The rechargeable battery, designed with a lead latticework grid, is introduced.

Constantin Senlecq, a French lawyer, invents the teletroscope.

1882:
Professor Amos E. Dolbear of Tufts University communicates over a distance of a quarter of a mile without wires and is issued a US patent for a wireless telegraph.

Striving to capture the minute details of motion, Dr. Jules Etienne Marey, a French physiologist, develops the fusil photographique, or photographic pistol. It can take 12 consecutive pictures per second.

Edison's Pearl Street station begins operation in New York

The induction coil system or "secondary generator" is developed by Lucien Gaulard in France, and John Gibbs in the UK.

1883:
Thomas Edison accidentally discovers what comes to be known as the "Edison effect" while trying to find a way to keep the inside of his electric lights free of soot.  While experimenting with the incandescent bulb, Edison placed a metal plate inside the evacuated bulb and connected a wire to it creating, in effect, a vacuum diode!  He noted a curious unidirectional or "one-way" flow of electrical current from the light emitting hot filament across the vacuum to the metal wire. This phenomenon defied immediate explanation by the inventor as well as his contemporaries.  Unfortunately, he did not realize the implications - or did not take time to pursue them because of other interests at the time. The current flow is due to the thermionic emissionof electrons from the hot electrode flowing to the cold electrode. The Edison effect is the basis of all the vacuum tube devices, and, thus, the foundation of the electronics industry in the early 20th century.

Edison patents the Fuse.

Fitzgerald predicts the existence of electromagnetic waves

1884 :
T. Calzecchi-Onesti, in Italy,  carefully studies studied how the resistance of metal filings in an ebonite or glass tube is effected by electrical discharges.
German scientist Paul Gottlieb Nipkow patents his electric telescope a device for scene analyzation that consisted of a rapidly rotating disk placed between a scene and a light sensitive selenium element.  What has became known as the Nipkow disk is a spirally perforated disc that rotates in front of the image to be analyzed and, thus, progressively reveals the image to the sensor.. Although a mechanical design, it was the first system, to propose and embody the principle of image scanning. It is believed a working model was never built by Nipkow himself. It would take the development of the amplification tube before the Nipkow Disc would become practical.

A synchronous multiplex telegraph system is designed by Patrick Delany, allowing several operators to use the same telegraph line at once, instead of sharing it on a cyclic basis.

Etienne Jules Marey develops the 'Chronophotographe' and in the coming decade, in collaboration with Georges Demeny, perfected techniques for both the analysis and synthesis of movement.

Gulielmo Marconi first experiments with Hertzian Waves.

A practical design for a commercial transformer is produced by Max Deri, Otto Blathy and Karl Zipernowsky.

1885:
J. J. Thompson uses magnetism to deflect Crookes' 'cathode rays'.

Edouard Branly begins his work investigating the transmission of nerve impulses. His research over the next several years will result in what will later be called the 'coherer' - a device for detecting 'Hertzian waves'.

1886:
Eugene Goldstein, a German physicist, identifies canal rays in the electric charge carriers inside the discharge tube. The canal rays are composed of different, positively charged ions in the gases formed by the discharge.

The electric light bulb or "bayonet cap" is marketed in the UK by the Edison & Swan United Electric Light Co. The firm represents the combined forces of Thomas Alva Edison, the American inventor, and Sir Joseph Wilson Swan, the pioneering English chemist and physicist who made an incandescent lamp using a carbon filament 20 years before Edison's lamp.

The chemical element germanium is discovered by German chemist Clemens Alexander Winkler. He isolates the silver-grey metal from the mineral argyrodite, which is a mixed sulfide of silver and germanium. The existence of germanium, named after Winkler's homeland, was predicted in 1871 in the Russian chemist Mendeleyev's periodic table, hypothetically named "ekasilicon." It will be used extensively in the manufacture of semiconductor materials and devices.

At the Volta Laboratory in Washington, DC, Chichester Bell and Charles Sumner Tainter develop the graphophone, a variant of Edison's phonograph. They substitute wax for tinfoil as a covering for the cylinder, and use a sapphire stylus.

1887:
In a remarkable series of experiments, Heinrich (Rudolph) Hertz (1857-1894), a professor at the Karlsruhe Polytechnic, establishes the validity of Maxwell's theoretic analysis by showing that a field generated by an electric spark can travel through space as waves and that these waves have the same physical properties as light.  In particular, he demonstrated that the velocity of these electromagnetic waves is equal to that of light.  Hertz never tried to use electromagnetic waves for communication and even denied the practicability of such an undertaking.

Thomas Edison starts research work into motion pictures.

An American Episcopalian minister Hannibal Williston Goodwin (1822-1900) invents the use of celluloid as an emulsion base, an essential step in the development of cinematography. He became interested in photography through the magic lantern entertainments he gave for his congregation.

The number of telephones in service in the US reaches 200,000. Boston has over 5000 phones, Hartford and New Haven each have more than 1000.

Oberlin Smith imagines the tape recorder.

1888:
German physicist Wilhelm Hallwachs noted that certain substances emit electrons when exposed to light. Hallwachs demonstrated the possibility of using photoelectric cells in cameras. This property called photoemission was applied in the creation of image orthicon tubes allowing the creation of the electronic television camera.

Tired of the unwieldy glass plate system normally used in his work, photographer John Carbutt commissions a celluloid manufacturer to provide him with thin sheets, coated with emulsion, that will roll through a camera. This same year, George Eastman will market a paper photographic film in rolls.
Up to this point, photography has been the exclusive domain of professionals. With the introduction of the flexible roll film camera by a dry plate manufacturer named George Eastman, it is now made available to anyone who can press a button. The inexpensive, fixed-focus Kodak camera uses roll film with a paper base, coated with a photosensitive emulsion. One roll of film has the capacity for 100 circular pictures with a 2 1/4in diameter. The Kodak, which establishes Eastman's hold on the photographic products market, is made famous with the slogan "You press the button, we do the rest."

W. K. Laurie Dickson ( working for Edison ) starts to develop Kinetograph camera.
 

Louis Le Prince's camera initially uses paper roll film but changes to the new Eastman celluloid film in 1899. Le Prince, his films and equipment disappeared without a trace in September 1890.

A commercial model of the phonograph, first devised by Thomas Edison almost ten years earlier, is built in his Menlo Park laboratory. It is equipped with a clockwork motor and wax cylinders.

1889:
Lazare Weiller scans with mirrors on a revolving drum.

At the Eastman Kodak factory, Henry Reichenbach using a nitro-cellulose base creates celluloid roll film, an improvement on Eastman's earlier emulsion-coated paper variety.

Thomas Edison and his assistant, William Kennedy Laurie Dickson, patent and market an electric peephole viewing machine called the Kinetoscope. It uses 158 glass plates, later to be replaced by Eastman and Goodwin's roll film which projected a 50ft length of film in approximately 13 seconds. Having little faith in the Kinetoscope or motion pictures in general, Edison neglects extending his patent rights to England and Europe. Within the next five years, two Frenchmen will manufacture the portable Cinematographe projector based on Edison's ideas, initiating the era of motion pictures.

A coin-operated telephone for public use is designed by William Gray, and the prototype is installed at the Hartford Bank. Soon the Gray Telephone Pay Station Co. is established to rent the devices to merchants and businesses.

Thomas Edison and his assistant William Kennedy Dickson develop the Edison camera or Kinetograph, using the phonograph as a foundation for the device. Dickson abandons the wax cylinders for celluloid film, a far superior medium for motion pictures, and between 1891 and 1895, shoots the first films. Each averaging about 15 seconds, these films are designed be shown on the Kinetoscope. Edison's disinterest in the Kinetograph and its European patent rights opens up the field for the Lumiere brothers, who develop the Cinematographe in 1895.

1890:
Edouard Branly, Physics Professor at the Catholic University of Paris, found that a nearby electromagnetic disturbance can lower the resistance of a thin layer of copper and is, thus, credited as the inventor of the coherer wireless detector.

Michael Pupin studies low pressure vacuum-tube discharges, and invents an electrical resonator.

Charles Driffield and Ferdinand Hurter publish their work on emulsion sensitivity and exposure measurement

The Kinematograph camera and projector are publicly demonstrated in London. Invented by William Friese-Green, a Bristol born photographer and self-taught scientist, the camera is able to take pictures on modified celluloid film at 50 fps (frames per second) by means of parallel sprocket holes. Friese-Green's invention is unreliable and does not meet with great success.

 The High Frequency Generator is invented by Elihu Thomson, a US engineer and inventor, with Edward James Houston.

1891:
Thomas Edison receives a patent for wireless telegraphy.

Edison patents 'Kinetograph' camera and 'Kinetoscope' viewer. The Kinetoscope is not a projector. The coin-operated machines were introduced in public parlors in New York City in 1894 and appeared in London, Berlin, and Paris before the end of the year.

Suspecting that his competitor's wife - an operator at the local telephone exchange - is redirecting business calls to her husband's company, Kansas City undertaker Almon Brown Strowger creates the automatic telephone switchboard. He patents what he calls a "girl-less, cuss-less, out-of-order-less, wait-less" telephone system, which is activated when a caller selects a number by pressing a combination of three buttons. Also in 1891, Strowger patents a dial telephone and founds the Automatic Electric Co. to promote his invention. The first automatic system will be put into commercial use in La Porte, Indiana the following year. The Strowger system can link up to 99 subscribers, and is later licensed to ATT. In 1919, the Bell Telephone System will adopt the automatic switchboard and the dial phone.

In the same year he is granted his US citizenship, inventor Nikola Tesla constructs what is known as the Tesla coil. This air-core transformer converts low voltage high current to high voltage low current at high frequencies; it is soon considered essential equipment in research laboratories across the country, to supplement the weak oscillations of the Hertz circuit.

1892:
William Crookes distinctly foresaw the application of Hertzian waves to practical telegraphy in a paper in the Fortnightly Review in February.

Frederick Ives invents first complete system for natural color photography.

Telephone service between New York and Chicago commences.
1893:
The 'photoelectric cell' is invented by German physicists Julius Elster and Hans F. Geitel. Also called the 'photocell' or 'electric eye', the photoelectric cell varies its electric output in relation to the light it receives.
Thomas Edison patents Dickson's 'Kinetoscope' under his own name.

The Kinetographic Theater, a film studio, is designed by W.K.L. Dickson, an associate of Thomas Edison, at Menlo Park, New Jersey. The entire studio revolves on a pivot to follow the sunlight. It is nicknamed 'The Black Maria'

Edweard Muybridge projects many of his sequences of human beings in motion at the Chicago fair, in a specially constructed building of classical design, the Zoopraxographical Hall, a forerunner of the Cinema theatre

Electricity wizard Nikola Tesla has applied for and received over 40 US patents on the AC electrical system, which will form the basis of electrical power distribution systems throughout the world. The competition between the Westinghouse - Tesla alliance and Thomas Edison is fierce. Edison has ignored Tesla's discoveries in favor of his own direct current electrical system, but the DC method ultimately fails because it is unable to distribute power efficiently for more than a few miles. Unwilling to accept his competitors' success, Edison wages a venomous smear campaign which includes the electrocution of small animals with AC power, to demonstrate its potential danger to the public. Despite such efforts, the inventor fails to turn the tide of progress. In 1893, Edison loses the competition to supply the Niagara Falls with hydroelectric power generation facilities. Westinghouse and Tesla win the contract, and the 15,000 hp two-phase facility is up and running by 1895.
Nicola Tesla demonstrated his system for wireless signaling.  Tesla successfully tested a small radio controlled and powered boat on a lake at New York's Madison Square Gardens.

1894:
Oliver Joseph Lodge delivered a series of seminal lectures entitled "The Work of Hertz and Some of His Successors."  In particular, he emphasized that Branly's powders were "The most astonishingly sensitive detector of Hertz waves" and coined the term "coherer."
Guglielmo Marchese Marconi (1874 - 1937) embarked on a study of the research of Hertz (who had died that year) and began to speculate that Hertzian waves might be used in communication. His interest was presumably prompted by a commemorative article written by Righi, since he had been familiar with the mathematical conclusions of Maxwell and Kelvin.  He had also read a description of the results obtained by Branly and Onesti, with detectors consisting of imperfect electrical contacts.  Marconi started his experiments on the application of Hertzian waves to wireless telegraphy in late 1894 at the the family estate,Villa Griffone, in Pontecchio Bologna. (Source1 and Source2)
US inventor Charles Francis Jenkins patents the phantascope, one of the first practical motion picture projection machines.

Michael Idvorsky Pupin, a Hungarian physicist and former student of Hermann von Helmholtz, is now living in the United States, where he makes innovations in multiplex telegraphy

1895:
On May 7 Alexander  Stepanovitch Popov (1859 - 1906) demonstrated a system for detecting distant electromagnetic disturbances (viz. lightning discharges in the atmosphere many miles away) before a meeting of the Russian Physical and Chemical Society in St. Petersburg.  Popov's receiver consisted of a metal filings coherer he had developed as the detector element together with an antenna, a relay, and a bell.  The relay was used to activate the bell which both announced the occurrence of a lightning discharge and served as a "decoherer" (tapper) to ready the coherer to detect the next lightning discharge. (Source)
The young physicist Ernest Rutherford (1871-1937), newly arrived at Cambridge from New Zealand, employs an magnetic effect to detect Hertzian waves over a distance of two miles. Only twenty-four, Rutherford delivers an experimental lecture on this research before the Cambridge Physical Society. (This lecture is later published by the Royal Society of London.)  In fact, Rutherford's 1894 work, in New Zealand, on the magnetic detection of electromagnetic waves had resulted in two substantial scientific papers and won him a scholarship, which provided for further education in England. (Source)

Marconi continued his experiments on Hertzian waves at Villa Grifone throughout the year.   Using oscillators similar to those used by Hertz and Righi (although Marconi's had much greater capacitance and hence greater radiating power), he discovered that the distance over which signals could be transmitted and received, varied in proportion to the square of the length of the vertical wires (antenna or aerial) attached to the transmitter or the receiver.  In particular, he found 2m antenna gave a range of 30m, a 4m antenna 100m and an 8m antenna a range of 400m.  He also devote a great deal of effort to improving performance of Branly's mysterious coherer detector.  Finally, in early summer (or September or March 30, 1995) and despite an intervening hill, Marconi achieved signal transmission and reception (three dots -- i.e., the letter "S") over a distance of about 2.4 km. (Source1 and Source2)

Captain H. B. Jackson, a scientifically minded officer at the British Royal Navy's Torpedo School, constructed a wireless set that would send Morse code signals from one end of a ship to the other. The following year, he performed the same experiment from ship to ship within a harbor. (In September of 1896, Captain Jackson was an observer at Marconi's demonstration on Salisbury Plains.) (Source)

Wilhelm Conrad Röntgen discovers x-rays

Louis and Auguste Lumière issued a patent for a device called a cinematograph capable of projecting moving pictures and on Dec 28, 1895, the brothers show the first motion pictures at the Grand Cafe on the Boulevard Des Capucines.

In the US, Enoch Rector invents a device to prevent motion picture film from breaking in the camera. The device is called the Latham Loop, after Rector's employers, the Latham Brothers. Thomas Armat produces the same device independently for his Vitascope Beater Movement projector.

 May 1895 - Birt Acres ( 1854-1918 ) patents his Kineopticon and becomes the first Englishman to successfully produce and publicly show animated pictures, initially at the Royal Photographic Society in London on 14th January the following year. The demonstration includes film strips of the 1895 Derby and the opening of the Kiel canal by the German Emperor.

Photographic typesetting (kinematography) is invented by William Friese-Greene, of London. He takes out a patent but his system is never built for commercial use.
1896:
January:
After eighteen  months of experimentation and development, Marconi and his family were convinced that his wireless telegraphy system was patentable and ready for public demonstration.
February:
Marconi and his mother (nee Annie Jameson whose family was the Jameson Distillers of Belfaest) travelled to Great Britain in pursuit of two alternative and, perhaps, conflicting strategies.  Prior to applying for a patent he felt that he should make his information available to the Italian government and seek some financial help from the government's Post and Telegraph Service.  To that end, he and his mother contacted a family friend, General Ferrero, who was the Italian Ambassador in London.  After many months of consideration, there apppeared to be little enthusiasm for his invention in Italy: in fact, the appropriate Italian minister reported that it was "not suitable for telecommunications!"   While awaiting response from the Italian government,  Marconi and his mother were using the influence of the Jameson name to provide introductions to important people in positions to help get support for the further development.  In particular, she secured a hearing before Sir William Preece (1834-1913), then Engineer-in-Chief for the Post Office, who immediately saw the importance of Marconi's apparatus.

With the help of the Jameson family money and connections he set up the Wireless Signal Telegraph Company which later became the Marconi Wireless Telegraph Company. (Source)

March:
March 24, 1896 Alexander Popov demonstrated the transmission and reception of information by wireless telegraphy before another meeting of the Russian Physical and Chemical Society ate St. Petersburg University.  The message "HEINRICH HERTZ" was transmitted a distance of over 800 feet between two campus buildings. (Source)
June:
On the basis of the small scale trials in Bologna and with the guidance of his cousin Henry Jameson Davis, Marconi, on June 2nd , files the world's first patent application for a system of telegraphy using Hertzian waves -- British Patent number 12039.  Because of the need to protect his patent interests, the specific details of Marconi's equipment are not disclosed publicly until June 4, when William Preece gaves a public lecture at The Royal Institution in London. The lecture is published in the next issue of The Electrician.
July:
Marconi demonstrates his apparatus to both the Post Office and the War Office in a sequence of trials of in London .
September
A historic demonstration takes place at Three Mile Hill on Salisbury Plain on the September 2nd, with officials from the GPO, the Navy and the Army present.
Thomas Edison, using Thomas Arnat's 'Vitascope', shows the first motion pictures in the USA in Koster and Bial's Music Hall in New York.

Thomas Edison's company, General Electric, licenses Nikola Tesla's AC (alternating current) system and in 1896 builds a transmission and distribution system linking the Niagara Falls Powerhouse to Buffalo, NY. This signals the winding down of the war between Edison and Westinghouse over the superiority of the electric currents, Edison having failed to win the public over to his own DC (direct current) system. Westinghouse, the first to supply the Niagara Falls with hydroelectric power generation facilities, will eventually build seven more generating units, raising the yield to 50,000 hp. The high-yield AC voltages make possible the manufacture of aluminum, as Tesla had predicted, and enables the Pittsburgh Reduction Company--later to be known as the Aluminum Company of America (ALCOA)--to feed raw materials to the youthful aircraft industry.

1897:
Thus, he received from the British government the first wireless patent which was based, in part, on the theory that the communication range increases substantially as the height of the antenna is increased. He continued through 1897 with trials over water and reached 18 miles in November of that year.
March:
Marconi was back on Salisbury Plain and achieved a range of 7 miles (11.2 km).  A complete patent specification is filed on March 2, 1897.

Popov equips a land station at Kronstadt and on the Russian navy cruiser Africa with his wireless communications apparatus for ship-to-shore communications.

May:
On the fourth day of a series tests across the Bristol Channel Marconi achieves new record range of 8.7 miles (14 km) with an aerial at 300 feet  and a 20 inch spark coil (at a wavelength of 1.25 m).  The Morse message sent was "let it be so."
ing the support of the Chief Engineer of the British Post Office, Marconi patents his system in England and, in 1897, founds the Wireless Telegraph and Signal Company, Ltd. In 1900 the name of the company will be changed to Marconi's Wireless Telegraph Company, Ltd.April 23, (Source1, Source2 and Source3)In the summer, Marconi's Wireless Telegraph and Signal Company, is incorporated under the laws of England.  Later (1900) the name is changed to Marconi's Wireless Telegraph Company
 
 

                       One of the first practical applications of wireless came in 1898, when
                                Marconi followed the Kingstown Regatta in a tugboat and flashed the
                                results in code to the offices of a Dublin newspaper. In 1899 the value of
                                wireless telegraphy in saving lives at sea was first demonstrated. The
                                East Goodwin Sands lightship was rammed in a fog, and aid was
                                summoned by wireless.
Karl Ferdinand Braun constructs the first cathode ray to incorporate a scanning capability.

Marconi was granted a patent on July 2, 1897 (

Josef Maria Eder and Eduard Valenta publish stereoscopic Röntgen photographs.

At the University of Strasbourg, German physicist Karl Ferdinand Braun invents the 'oscilloscope', the first cathode ray tube (CRT). In this laboratory device ( the forerunner of television and radar tubes ) a narrow stream of electrons traces patterns on the fluorescent screen of the tube. Braun is also the inventor of the crystal rectifier, a device that allows current to flow in only one direction and improves radio transmission. He will share the 1909 Nobel Prize with Guglielmo Marconi for the development of radio.

The British Ministry gives Marconi money and technicans to continue his work. Marconi signals reached 5, 8, 15, 30 and 100 km. In July Marconi formed the Wireless Telegraph Trading Signal Co. Ltd.

J. J. Thomson, head of the experimental physics program at Cambridge University in England, discovers and identifies units of electrical current--electrons-- in cathode rays. Thomson believes that these units are a fundamental part of all matter. He suggests that in a model of atomic structure, the negatively charged subatomic particles, electrons, are embedded in a sphere of positive electricity, and that the two charges neutralize each other. Thomson's findings revolutionize the study of physics, and win him the Nobel Prize 1906. The strength of his gift as a researcher and a teacher is evidenced by the fact that seven of his research assistants, and his son George, will win Nobel prizes, and he will lead his country to the forefront of the field of subatomic particles in the early 20th century.

The oscillograph is invented by William du Bois Duddell, a British engineer.

The American Mutoscope and Biograph Company (later to be known as Biograph) produces the mutoscope, a peep-show viewer developed to rival Edison's Kinetoscope. The device uses large cardboard photographs that flip when a hand crank is rotated, and outperforms the Kinetoscope with its electrically driven film strip. Mutoscopes can still be found at some carnivals, amusement parks and penny arcades.

1898:
May:
Lloyds of London, the marine underwriters's association, invites Marconi to install an experimental wireless link between Rathlin Island and Ballycastle (on the coast of Ireland) as part of a  maritime intelligence network.  George Kemp reports having received "a few V signals" from Rathlin Island on July 6th (source).


July:

As  one of the first practical applications of wireless, Marconi radio reports the Kingston Yacht Regatta for Dublin's Daily Express.


September:

Marconi comes to the US, where he demonstrates for the Navy a telegraph link between the cruisers New York and Massachusetts.


John G. Pickard (for American Wireless Telephone and Telegraph Company), Lee de Forest (for Wireless Telegraph Company of America) and Guglielmo Marconi (for Marconi Wireless Telegraph and Signal Company, Ltd.) battle to cover the America Cup Race in September and October.
 

Marconi was called back to Italy by the minister of the Italian navy. As a naval officer, he conducts some of his most important experiments aboard naval ships.

Lodge invents a means of radio tuning (the sintonic circuit) and is granted a patent in the USA.

The Bellowing Telephone (a speaker phone) is developed by Sir Oliver Lodge, Professor of Physics at University College, Liverpool.

The loudspeaker is invented by Horace Short of London. The compressed air "Auxetophone" is first used to broadcast records of operatic arias from the tops of the Blackpool Tower in England and the Eiffel Tower in France.

December 1 - Danish electrical engineer and inventor Valdemar Poulsen ( 1869-1942 ) patents the first practical magnetic sound recorder, the 'Telegraphone', using magnetised piano wire as the recording medium. Poulsen demonstrates his device at the Paris Exhibition of 1900, and later adapts it to create a recording telephone.

1899:
The first wireless telegraph message is sent across the English Channel by Marconi in March.

The Marconi's Wireless Telegraph Company of America is formed on November 22nd  and, eventually becomes the Radio Corporation of America in 1919.

After being rammed by a freighter the East Goodwin Sands Lightship, on the evening of March 3rd sent the first recorded maritime radio request for help. (Source)

Nikola Tesla, gazing at the Colorado Springs skies during a Fourth of July electrical storm, makes what he believes to be his most important discovery. By studying the movement of clouds, he perceives the existence of terrestrial stationary waves that transmit energy, and is thereby assured of the possibility of wireless telegraphy (which he has suspected for some time).  Even more fantastic is the fact that using the earth as a conductor will make possible the transmission of unlimited power to any location on the planet.  This means, among other things, that the modulations of the human voice can be heard around the world. Tesla builds a magnifying transmitter and, in one experiment, lights 200 incandescent lamps from a distance of 26 miles without the use of wires. In the most spectacular demonstration of his career, he creates a bolt of lightning 135 feet long, the crack of which can be heard 15 miles away from his laboratory. The experiment is cut short only by the Colorado Springs Electric Company who, complaining of a burned out generator, crisply informs him that his service is thereby terminated. It is during this same year that Tesla receives what he believes to be communications from Venus or Mars. Public reaction ranges from the polite to the incredulous, but sixty years later scientists will acknowledge the fact that radio signals from beyond our atmosphere are indeed often picked up by earthbound receivers.

Valdemar Poulsen of Denmark invents a sound recording device, forerunner of the modern tape recorder. Poulsen's invention, which he calls the telegraphone, records sound on a magnetic wire. Poulsen demonstrates his device at the Paris Exhibition of 1900, and later adapts it to create a recording telephone.

In the US, Michael Idvorsky Pupin, an immigrant Hungarian physicist and inventor, devises the so-called Pupin "loading" coil - a system for extending the range of long distance telephone service by placing inductance coils around the transmitting wires. AT&T patents the invention in 1901.

A photoelectric cell designed for practical use is invented by German physicists Julius Elster and Hans Friedrich Geitel. Originally introduced in 1893, photoelectric cells permit the conversion of luminous flux into an electric current. Thereafter, variations in light are transmitted by an electric current and then turned back into identical light variations upon arrival. The end result is the successful transmission of static or luminous imagery.

November:

The Marconi's Wireless Telegraph Company of America is formed on November 22nd (it
became the Radio Corporation of America in 1919).
1900:
Reginald Arbrey Fessenden is hired by Weather Bureau to work out means to obtain weather reports from and to provide forecasts to offshore light vessels and isolated locations.  He became interested in voice transmission and, as a result, developed the concepts of amplitude modulation (AM).  Fessenden theorizes that an alternator, as developed by Tesla, could generate an electromagnetic wave able to carry voice and music.  He uses a spark generator to send the human voice the distance of about one mile.

Marconi filed for the now-famous (or infamous) patent No. 7777 for an "oscillating sintonic circuitÖ" -- the basis for frequency multiplexing.

The crew of the battleship General-Admiral Apraksin is saved in the Gulf of Finland as a result of distress call relayed by Popov's radio system (variously reported as 1899 or 1901).

A "car radio" is invented by Guglielmo Marconi.  The radio is installed inside a fully equipped Thornycroft steam wagon, and used for wireless telegraphy experiments.
                  In 1901 Marconi achieved a dramatic success when he transmitted signals
                                across the Atlantic Ocean by wireless. Other scientists had thought this
                                impossible, believing that radio waves traveled only in straight lines.
                                Marconi, however, thought that the long waves he used would follow the
                                curvature of the Earth. This was proved when, on Dec. 12, 1901, he
                                received signals in St. John's, Newf., sent from a transmitter in Poldhu at
                                the southwestern tip of England.

First mass-marketed camera, 'The Kodak Brownie'

The Wireless Telegraph Trading Signal Co. Ltd changes its name to the 'Marconi Telegraph Co.' Marconi gets his English patent for his tuning equipment.

1901:
On December 12 the first transatlantic communication, which involved sending the Morse-code signal for the letter "S" from Poldhu, Cornwall in southwest England, 2170 miles across theAtlantic to an aerial device suspended from a kite in St. John's, Newfoundland, Canada, England, to Saint John's, Newfoundland.  John A. Fleming was at the transmitter in England.

Karl Ferdinand Braun introduces the use of a crystal detector as part of a wireless receiver.

1902:
The magnetic detector is invented by Marconi.

The DeForest Wireless Telegraph Company is formed.

Valdemar Poulsen invents the arc converter as a generator of continuous-wave radio signals.

Fessenden developed and demonstrated the heterodyne principle.  Fessenden forms the National Electric Signaling Company.

Arthur E. Kennelly and Oliver Heaviside independently discover a reflective layer (i.e. the ionosphere or Kennelly-Heaviside layer) in the upper atmosphere (at about 100 miles).

Marconi station on Nantucket Shoals Lightship refused to accept message to President Roosevelt from Prince Henry of Prussia on the SS Deutschland.

Arthur Korn transmited pictures over wire before devising a system for broadcasting them by radio

 Otto von Bronk applies for German patent on color television

 Trans-Pacific telephone cable connects Canada and Australia

 Marconi builds a radio station at Glace Bay, Nova Scotia It is during the trip that he discovers the harmful influence of solar radiation on tramissions. Thus the creation of the Magnetic Detector.

 The station at Glace Bay was set up as the transmitting station, while the station in Europe at Poldhu was the receiving station. They would use the cable line as a means to verify communications between the two stations. On December 15th the first offical messages came through from Table Head to Poldhu saying 'we have received some signals'.

 The layer of the earth's atmosphere known as the ionosphere is perceived simultaneously by Arthur Edwin Kennelly, Professor of Electrical Engineering at Harvard University in Cambridge, Massachusetts, and physicist Oliver Heaviside at the Great Northern Telegraphy Company in England. The discovery explains Marconi's success in making radio contact over the curved surface of the earth; it is the upper ionized layer of the atmosphere that reflects radio waves. Signals are clearer at night because during the day the sun's heat expands the air and pushes the layer upward, making the signal weaker.

1903:
Marconi establishes the first press agency between Europe and America. Jaunary 18th the first two-way transatlantic transmission between Poldhu, England and Cape Code Mass. USA.

The First International Radio Telegraphic Conference, Berlin.

Fessenden generated continuous electromagnetic waves with an alternator and patented the electrolytic barretter which was the first practical continuous-wave detector.

Marconi's South Wellfleet (Cape Cod), Massachusetts station linked to his Poldhu (Cornwall), England station on January 19, 1903 (some specs: wavelength 1500 to 1800 meters; 30,000 watts; 2200 volt alternator stepped up 25,000 volts by transformer).

1904:
Fessenden invents 'Heterodyne reception'.

John Ambrose Fleming (University College, London) serves as a scientific consultant to the Marconi company, and designs many pieces of early wireless apparatus. In particular, he is charged to develop a  new detector for wireless signals and devises the two-element "Fleming Valve" (or as he calls it..an Oscillation Valve) thermionic rectifier based on the "Edison effect" which had been known since 1883.  His valve is a two element rectifier, made by inserting a metal plate in one of Edison's electric light bulbs.The diode, a two-terminal electron tube, is patented by Marconi's British colleague John Ambrose Fleming. Working from Edison's discovery that heated metal (cathode) will give off electrons which, in a vacuum tube, will move in one direction only toward an unheated plate (anode), Fleming constructs a tube in which he places a cathode, an anode and two electrodes. His discovery, the first radio wave detector, ( capable of 'rectification' ) opens the door to advanced radio communication.
 

Fessenden commissions General Electric to develop a frequency alternator as a source of high-power, continuous-wave radio-frequency radiation for transoceanic radiotelegraphy.  Ernst F. W. Alexanderson (an engineer for General Electric and, later, Radio Corporation of America) was assigned to the project .

Christian Hulsmeyer (Germany) developed and patented a primative form of radar.

First colour television system is proposed based on the principle of scanning three primary colours.

Guglielmo Marconi buids the 'Rotating Oscillator' and discovered the directive properties of horizontal antennas. Starts to use the Fleming thermionic valve.

The answerphone, an automatic telephone answering machine, makes its debut. Based on Valdimir Poulsen's Telegraphone, the first practical tape recorder, it answers phone calls and records messages.

1905:
Guglielmo Marconi patented his directive horizontal antenna.

Italian physicist Guglielmo Marconi develops the concept of the bent ( or directive horizontal ) antenna; that is, that the best reception is achieved when the free end of an antenna wire laid on the ground points away from the transmitting station. The "aerial" antenna is first tested at Marconi's Glace Bay Station in Canada, markedly broadening its reception range. Marconi's findings will prove particularly valuable in World War I, as they lead to the development of techniques in radio direction finding.

 The Pathe Company devises a stencil system for film coloring that makes it possible to color a black and white film at high speed. This efficient system replaces the painstaking method of handcoloring each frame which, at the rate of 1,000 frames per minute of film, is extremely tedious and time consuming. Pathe's automated film coloring system will be used with great success for the next 25 years.

1906:
First wireless communication of human speech (and music) on December 24, 1906.  Fessenden spoke and broadcasted music by radio from Brant Rock, Massachusetts, to ships in the Atlantic Ocean using a two kilowatt (100 kHz) alternator developed by Alexanderson.  Fessenden modulates continuous wave.

Lee DeForest develops the 'Audion', a three element ( three electrode or triode ) vacuum tube. This made amplification of video signals created by photoconductivity and photoemission possible.

 also...

 The triode vacuum valve, a three-electrode vacuum tube, is invented by Lee De Forest in New York. Adding a third valve to Sir Ambrose Fleming's diode, produced two years earlier, de Forest's "Audion" can generate, detect and amplify radio waves. The triode revolutionizes radio communications, providing the first technology for loud and clear radio transmission of the human voice. The earliest receivers or crystal sets pick up single wavelength transmissions, which are listened to through headphones.

 Boris Rosing of Russia develops the world's first working television system combining the cathode ray with a Nipkow disc.

 The 'Alexanderson Alternator' is delivered to Fessendon's station.
On Christmas Eve, 1906 he broadcasts speech and music to surprised
shipboard operators. He broadcasts on 42 Kilohertz at 1 kilowatt. The
programming includes a female voice singing a Christmas carol, a violin
solo by Fessenden, and an invitation to report on reception.The first radio program of speech and music ever broadcast is the work of Reginald Aubrey Fessenden, a Canadian-born American physicist and electrical engineer. The transmission originates on Christmas Eve from the National Electrical Signaling Company's radio station in Bryant Rock, Massachusetts. Featured on the program are a violin rendition of Gounod's "O Holy Night," and verses from St. Luke's Gospel along with a Christmas greeting read by Fessenden himself. The wireless broadcast reaches ships over a radius of more than 100 miles.

Greenleaf Whittier Pickard uses a fused silicon detector

Max Wien uses cooled gaps and quenched gaps in his spark transmitters.

American Henry H.C. Dunwoody patents the carborundum crystal radio detector, an integral element in the new wireless industry. The earliest method for detecting radio waves, the carborundum crystal allows current to flow in one direction, so that only the upper half of the modulated wave is allowed to pass. Dunwoody's work will lead to the advent of the crystal set in 1910, making it possible for amateurs to build their own wireless receivers and hear early radio transmissions. Carborundum is the trademark for silicon carbide and other abrasives.

 The Bell Telephone Laboratories install a dial telephone switching system in telephone exchanges across the US. The automatic system was originally devised by American undertaker Almon Brown Strowger in 1889, and will remain in wide use through the 1980s.

1907:
Financial panic delays many developments in radio technology.
Edouard Belin (France) invented a procedure for the transmission of photographs by telegraph and radio.

The first 'Broadcasts' of records are done to aid in testing, so the
operator didn't have to talk.

Boris Rosing transmits black and white silhouettes of simple shapes, using a mechanical mirror-drum apparatus as a camera and a cathode-ray tube as a receiver.

The cathode ray tube ( CRT ), first produced in 1897 by Ferdinand Braun, is the subject of significant experiments by Russian physicist Boris Rosing. Professor Rosing is the first to suggest that the electrical signals from a mechanical transmitter might be transformed into visual images when sent to a cathode ray tube receiver. Working in his St. Petersburg laboratory over the next five years, Rosing uses a rotating mirror drum to scan geometric shapes, which he is able to crudely reproduce on the CRT. His studies will have a strong influence on the work of John Logie Baird, who is to give the first public demonstration of television in 1926.

 Lumière Brother's market the 'Autochrome' color process

 Alfred Korn announces Fac-Simile telegraphy

 G.W. Pickard perfects the crystal detector and takes out a patent for the use of silicon in detectors.

 A photograph of King Edward VII becomes the first newspaper wire photo, transmitted by radio telegraph. London's Daily Mirror publishes the picture, which is flashed from Paris over a 12 minute period.

A year after the first radio broadcast by Fessenden, engineer Ernst Alexander designs a high frequency radio alternator able to generate frequencies up to 100 kHz. This device, built for the General Electric Company, significantly broadens the range of radio transmission. Alexander will go on to invent both a magnetic and an electronic amplifier, as well as a mutiple-tuned antenna. At the end of World War I, President Woodrow Wilson will refuse the U.K.'s request to buy one of the powerful Alexander alternators.

U.S. patent granted to Lee de Forest for a "Device for Amplifying Feeble Electric Currents." on January 15, 1907.  He called it the "audion."  More sensitive version granted U.S. patent on February 18, 1908.

The Marconi Wireless, Telegraph and Signal Company produces transmitters and receivers for the military for use with telegraph decoding apparatus. Marconi establishes a commercial radio telegraph service across the Atlantic.

The worlds first Trans-Atlantic commercial wireless service is established by Marconi with stations at Clifden, Ireland and Glace Bay, Nova Scotia. Marconi begins to use rotary synchronous gaps in his spark transmitter.

1908 :
Radio played a key role in limiting the loss of life in collision of the White Star liner Republic and the Italian SS Florida on January 22, 1908.  A radio distress signal brings help in time to rescue all but five passengers when the U.S. Republic collides with the Florida, an Italian ocean liner. In all, 1700 lives are saved.
English inventor A.A. Campbell-Swinton and Russian Boris Rosing independently suggested using a cathode ray to reproduce the television picture on a phosphorous coated screen. This suggested that the electronic scanning system used in the CRT could replace the mechanical Nipkow disk.

 also...

 Outlining what will become the fundamental theory behind the television tube, Scottish scientist A.A. Campbell-Swinton proposes a method of electronic scanning where the cathode ray tube is used at the camera as well as the receiver end of the system. Swinton explains how the image is focused on a mosaic screen of photoelectric elements located in the camera, storing it there as an electric charge. The image is then reproduced on a picture tube by a scanning cathode ray beam that creates the TV signal. The scan is traced out line by line in the receiver to form the picture. Campbell-Swinton's theory forms the essential features of today's television system, although the primitive technology of the time does not allow it to be borne out in a practical demonstration. Not until 1923 will a stored-charge camera tube be patented. Gabriel Lippmann wins a Nobel Prize for his method of reproducing color by photography

 Motion picture color is pioneered by G.A. Smith with a system called Kinemacolor. In this two-color process, film is both taken and projected through red and green segments on a rotating wheel. An unfortunate drawback is that fast-moving objects are severely flawed by color fringing; kinemacolor therefore works best when focused on static objects, making it a less than perfect solution for color in movies.

 The De Forest 4th Avenue Radio Telephone Company in New York begins a program of regular radio broadcasts, consisting entirely of gramophone music.

 also...

 Lee De Forest makes the first radio broadcast from the Eiffel Tower in Paris.

 At a rate of fifteen cents per word, the public can send messages across the Atlantic. This is made possible by the first transatlantic radio-telegraph stations, based in Glace Bay, Canada and Clifden, Ireland.

1909:
Steel radio transmitter masts are tested in rural Chelmsford, England. The 200 ft structures will extend telecommunications across the Amazon rainforest as well as the cities of Europe.

 The mother-in-law of one of America's leading radio experts gives the first radio "talk" in broadcast history. Harriet Stanton Black bases her remarks on the controversial subject of women's suffrage.

 Recognizing the need for uniformity to avoid conflict between films and equipment, an international conference of motion picture producers selects the 35 mm film format as the standard for the motion picture industry. This important decision will open the door to the development of still cameras that use perforated film.

Charles 'Doc' Herrold begins a regular schedule of broadcasts from his "Herrold College of Wireless and Engineering" at San Jose, CA.

Marconi shares the Nobel Prize in Physics, with Karl Ferdinand Braun for their work in the development of wireless telegraphy.

1910:
In Sweden, Elkstrom invents 'flying spot' camera light beam

The Italian tenor Enrico Caruso broadcasts a concert from the Metropolitan Opera House over the radio. The few receivers able to pick up this first-ever outside broadcast are those on board ships in New York Harbor, in large hotels on Times Square, and at the De Forest Radio Laboratory.

The first commercial radios are sold by Lee De Forest's Radio Telephone Company in the demonstration room at the Metropolitan Life Building in New York City. De Forest's company both manufactures and retails these radios.

 In the US, John McCurdy, a pilot working for seaplane pioneer Glen Curtiss, transmits radio messages from his plane to the ground, pioneering air-to-ground communications.

 The French Pathe Brothers, Charles and Emil, begin production of the "Pathe Gazette," their pioneer newsreel. The Gazette is shown regularly in theaters in ther United States and Britain. The Pathe Brothers have film crews at work in Italy, Germany, Russia and Japan as well.

Boris Rosing (Russia) exhibited a television system which used mechanical scanner in the transmitter and cathode ray tube of Braun in the receiver.

1911:
On July 1, 1911 the Radio Ship Act of 1910 became effective.
Young radio amateurs are building receivers with whatever parts are
available. Although headphones can be purchased...many public telephone
booths become inoperative.

G. W. Pickard files 'catwhisker' detector patent

Scottish scientist A.A. Campbell-Swinton proposed a method of electronic scanning where the cathode ray tube is used at the camera as well as the receiver end of the system. Swinton explains how the image is focused on a mosaic screen of photoelectric elements located in the camera, storing it there as an electric charge. The image is then reproduced on a picture tube by a scanning cathode ray beam that creates the TV signal. The scan is traced out line by line in the receiver to form the picture. Campbell-Swinton's theory forms the essential features of today's television system, although the primitive technology of the time does not allow it to be borne out in a practical demonstration. Not until 1923 will a stored-charge camera tube be patented.

 Filmmakers experiment with electrically synchronizing motion pictures with sound recordings. Hepworth's "Vivaphone" and Walturdaw's "Singing Pictures" both feature actors lip-synching to current records.

 The Cavalry Brigade of the British Army forms a wireless company to handle communications in the field. The unit's equipment comprises an engine, a generator and a 50 ft collapsible antenna that weighs two tons and can be set up in 20 minutes. When all the gear is in place, it allows the company to communicate over distances of 50 miles.

 Direct telephone links from New York to Denver, Colorado are established.


1912:

 Professor R.A. Fessenden of Canada invents the heterodyne radio receiver. When it receives a signal, it generates another identical signal of its own. The two signals beat in synchrony and the resulting combined signal, called intermediate or modulated, is then amplified by circuits which suppress other frequencies, reducing noise. This system becomes standard by 1918 and is the basis for all modern radio reception.

 American electrical engineer Edwin Armstrong, while still a college student, invents the regenerative or "feedback" radio receiver. The feedback circuit compresses radio signals, amplifying the weaker and suppressing the stronger ones to achieve balanced reception. This receiver is much more effective over long distances than the crystal sets in domestic use. Armstrong's claim to the invention is contested by Lee De Forest as well as by a German scientist named Meissner. The dispute is eventually resolved in favor of De Forest and company.

The American chemist Irving Langmuir develops an improved vacuum tubes that will be employed in the new radio receivers.

 1912 - 1916. Max Wertheimer and Hugo Muensterberg show that illusion of continuous action is due, not to the optical properties of the retina, but to brain's inability to distinguish the difference between separate images at speeds 24 frames per second or more.

 Guglielmo Marconi invents a new way to generate a continuous wave, known as the 'Multiple Spark System'

 The Morse code sequence SOS (. . .---. . .) has been used by some fleets since 1909, when the shipwrecked ocean liner Slavonia first used it to summon two steamers to its aid. Now it is adopted as a universal distress signal by the navies of the world. It will be used frequently in World War I as military and civilian shipping alike fall prey to naval warfare.

 As a publicity stunt, Wanamaker's Department Store has 20 year-old Russian-American wireless operator David Sarnoff sit in the front window, demonstrating the telegraph. Sarnoff is at his post when he receives the SOS from the sinking Titanic. He contacts a steamer in the North Atlantic which wires back that it is picking up survivors.

Motion picture pioneer Leon Gaumont experiments with improved sound and color in motion picture film. "Chronochrome" is the first full three color process to be commercially developed. "Chronophone," a sound system, uses discs to play synchronized sound. The Chronophone demonstrations are highly popular and Gaumont is encouraged to combine the two innovations in the first public showing of color "talkies."

 London installs its first automatic telephone exchange. The 480 lines make it possible for Londoners to communicate by telephone without the delays and interruptions that have heretofore plagued the system. The British telephone industry is nationalized by an Act of Parliament. The other European powers have already nationalized their telephone services. Meanwhile in the US, there is demand to nationalize AT&T.


1913 :

 British scientist John Gott invents a system that uses current reversals for telegraph transmission. This solves the persistent problem of breaks in transmission where cables meet land lines, a problem that had made wire communication unreliable.

 1914 :

 Guglielmo Marconi experiments successfully using the triode thermionic valve, the birth of radiophony.

 also...

 Marconi produces the type 16 balanced-crystal receiver. Two crystals are connected so that one picks up Morse Code signals while the other screens out atmospheric interference. This enables ships at sea to transmit messages clearly, even during thunderstorms. This innovation proves to be of great importance in wartime emergencies.

US physicist R.A. Heising demonstrates the modulation of high frequency radio waves. The modulated wave can be separated by filters into a carrier wave and two sidebands, making it possible to transmit a more complex signal, improving the fidelity of broadcast sound.

 In the US, Langmuir invents a vacuum pump 1000 times more efficient than existing models. With this pump he is able to perfect the triode valve originally invented by Lee de Forest. The improved triode valve is to play an important role in the future development of radio. A telephone line between New York and Denver is "loaded", meaning that power is modulated on the line so that conversations can be heard very clearly. This line, which covers a distance of 2000 miles (3200 km) is the largest such line in use. Designer John Ambrose Fleming predicts the technology can be applied to distances as great as that between California and London.

 German-American inventor Edward Kleinschmidt introduces the teletype machine. It is no longer necessary for a telegraph operator to transcribe the messages as they come over the wire. The teletype uses the telegraph signal to power a typewriter which types the message automatically. By 1928 Kleinschmidt will have merged his company with that of his only competitor. In 1930, AT&T will buy th business for $30 million.

 1915 :

 Ray Kellog invents the The electric ( moving coil ) loudspeaker.

 American physicist Manson Benedicks discovers that the germanium crystal can be used to convert alternating current into direct current. This discovery will be the basis of the integrated circuit.

 Speech is transmitted across the Atlantic by radio-telephone. B. Webb of AT&T in Arlington, Virginia talks to Lt. Col. Ferries of the French Government using relay points in Canada and at the Eiffel Tower in Paris.

 Direct wireless telegraph communication begins between Japan and the US.

 Direct telephone communication is established between New York and San Francisco.

 Arnold and Carson of AT&T prove that each sideband of a modulated wave can carry a separate channel. This demonstration of single sideband radio increases the potential of telecommunications by making multi-channel transmissions possible.

 1916 :

 David Sarnoff envisions radio as 'a household utility' and submits his famous 'Radio Music Box' memo to executives at Marconi.

 Guglielmo Marconi started to develope the first VHF radios.

 Dénes Mihály, captain of hussars, registered a Hungarian patent on a writing mirror with which he incsribed sound vibrations on a strip of photographic.

 The development of aerial communication is given a boost when Major C.E. Prince demonstrates his wireless telephone, the Mark I, for Lord Kitchener, Britain's Secretary of State for War, by conversing with the pilot of an overhead plane.

 1917 :

 The condenser microphone, introduced to America by E.C. Wente, produces a clearer, more uniform sound than ever before. After some improvements, this state-of-the-art equipment will make high quality recordings and broadcasts possible.

 Edward Howard Armstrong develops the superheterodyne circuit and applies for a patent. This new electronic circuit significantly improves the sensitivity and selectivity of radio receivers over a wide range of frequencies, making amplifier tuning unnecessary. Fundamental to all AM radio receivers, it allows them to be tuned to different stations in a simple and straightforward manner.

 1918 :

 The imbalance that plagues hi-frequency reception is corrected by Prof. L.A. Hazeltine's welcome invention of the neutrodyne circuit. Stablility is achieved when the current feeds back into the circuit at the right strength.

 1919 :

 The British Marconi radio company has put in a bid to General Electric for the high-frequency Alexanderson alternator, an indispensable aid to long-distance wireless communication. The government is convinced this technology must remain in American control. In response to a request by President Woodrow Wilson, Rear Admiral W.H.G. Bullard of the US Navy and Owen D. Young of General Electric (GE) form the Radio Corporation of America (RCA) . It is initially established to function as a rival to British Marconi, which dominates radio communications, and is formed by taking over the assets of Marconi's American subsidiary. General Electric replaces British Marconi as the parent company, eliminating foreign influence over US broadcasting. To retain some control over the technology used so effectively for military communications and intelligence during the war, the US Navy holds a place on RCA's Board of Directors. Young is designated RCA's first president and Chairman. In 1920 AT&T will become an RCA partner, along with Westinghouse and United Fruit. The alliance represents the pooling of some 2000 electronics patents. An anti-trust action will soon split GE and RCA apart, leaving RCA to grow into a radio industry giant.

 The superheterodyne radio receiver goes into mass production, and will dominate the luxury item market in America for the next decade. The device makes uniform reception over a wide range of station frequencies possible for the first time, counterbalancing the incoming frequency against a second one to determine a precise fine-tune. As a result, the "superhet" is particularly sensitive to weak signals, and can tune into stations more selectively.

 American Telephone & Telegraph (AT&T) in Norfolk, Virginia introduces dial telephones to the general public. AT&T had rejected the idea earlier, but a threatened strike by telephone operators forces them to reconsider. Theodore Gary, owner of the Almon Strowger patents for dial telephone technology, acquires the Automatic Electric Company. Gary becomes rich manufacturing telephones for the Bell System; he eventually licenses Western Electric Company to make the dial phones.

American manufacturer Nicholson introduces the crystal microphone to the US. Soon to be widely used in home tape recorders and public address systems, the mike works on the piezo-electric principle where small voltages are produced on the surface of the crystal. While the economically attractive mike produces good sound quality, it is sensitive to heat, humidity, and rough handling.
 

1912: H. D Arnold (Western Electric) developed mercury-vapor discharge amplifier.
In April of 1912, David Sarnoff broadcasts first news about SS Titanic.
On October 30/31 of 1912, John Stone and Lee de Forest demonstrate a complete audion based audio amplifier to Bell officials.
Edwin H. Armstrong explained the operating principles of de Forest's audion: with this better understanding of amplifier operation, Armstrong applied "feedback" to obtain "regeneration" on signals or continuous oscillations (patented in 1913 and licensed to the Marconi company in 1914).
1912: Fessenden's patents heterodynes
1913: Armstrong invented the superheterodyne circuit
1914: Vacuum tube amplifiers used on transcontinental telephone lines in July of 1914.
1915: On February 10th of 1915, R. V. L. Hartley disclosed his famous vacuum tube oscillator circuit.  The "Colpitts oscillator" demonstrated a month later.
1916: Marconi's 200 kilowatt timed-spark continuous-wave (21.5 kHz) transmitter at Caernarvon (Wales) was put into service.
Sarnoff proposes idea of a radio music box

1912
Edwin Armstrong invents regeneration.
The ocean liner, "Titanic" hits an iceberg and sinks. The wireless distress
call was heard 58 miles away by the liner
"Carpathia". Those who made it into lifeboats were rescued 3 1/2 hours
later. There were 705 lives saved.
John H. Hammond, Jr. develops equipment to remotely control vessels by
radio up to three miles away. Later, many of his patents were sold to the
U.S. military for use in radio guidance in weapons delivery systems.

1913
Armstrong applies for a patent to use a vacuum tube as an oscillator.
A station in Nauen, Germany begins broadcasting on 16,900 meters...or about
18 kilocycles (just above the range of hearing!) Station FL, broadcasting
from the Eiffel tower begins broadcasting on 10,000 meters.

1914
Hiram Percy Maxim founds the A.R.R.L. American Radio Relay League.
War breaks out in Europe, and Amateur licenses are suspended in almost all
foreign countries.

1915
Human voices are first broadcast across the Atlantic ocean, between
Arlington, Virginia and the Eiffel Tower in Paris.

1916
David Sarnoff, an employee of the Marconi Company proposes 'radio music boxes' for the home as a potential business opportunity. He was ignored.
Wireless is used by the New York city police department.
Wireless telegraphy is made compulsory on all British vessels over 3,000
tons.

1917
America enters the First World War, and all patent protection is set aside
for the duration. Many advances are made in manufacturing and design due to
this measure.
Amateur radio experimenters pull down their antennas and pack away their
equipment by government order.

1918
Radio technology is used in detection of submarines, and by the US Signal
Corps in France.
5700 ships are now equipped with wireless telegraphy worldwide.
Special 'Hard' high vacuum tubes are designed for the Navy.

1919
The War is over!
Spark transmitters are being replaced by vacuum tube oscillators, and amateurs are beginning to switch to phone operation from CW (code)
Owen D. Young starts the Radio Corporation of America (RCA) - an offshoot
of General Electric. Within the year he has an agreement with GE, RCA, and
AT&T for sharing all radio patents between themselves.
Dr. Frank Conrad , a Westinghouse engineer, broadcasts a regular schedule
of records from his garage in Pittsburgh, and begins to take requests from
the avalanche of mail he receives. A local department store mentions those
broadcasts in one of their newspaper advertisements, and promptly sells out
of its radio equipment. Westinghouse takes notice, and begins to see the
possibilities for broadcasting.

1912: H. D Arnold (Western Electric) developed mercury-vapor discharge amplifier.
In April of 1912, David Sarnoff broadcasts first news about SS Titanic.
On October 30/31 of 1912, John Stone and Lee de Forest demonstrate a complete audion based audio amplifier to Bell officials.
Edwin H. Armstrong explained the operating principles of de Forest's audion: with this better understanding of amplifier operation, Armstrong applied "feedback" to obtain "regeneration" on signals or continuous oscillations (patented in 1913 and licensed to the Marconi company in 1914).
1912: Fessenden's patents heterodynes
1913: Armstrong invented the superheterodyne circuit
1914: Vacuum tube amplifiers used on transcontinental telephone lines in July of 1914.
1915: On February 10th of 1915, R. V. L. Hartley disclosed his famous vacuum tube oscillator circuit.  The "Colpitts oscillator" demonstrated a month later.
1916: Marconi's 200 kilowatt timed-spark continuous-wave (21.5 kHz) transmitter at Caernarvon (Wales) was put into service.
Sarnoff proposes idea of a radio music box
 

1920: Westinghouse Electric and Manufacturing Company inaugurated commercial broadcasting service on KDKA in Pittsburgh on November 2, 1920 (some specs: transmission at a wavelength of 360 meters and a power of 100 watts).
1922: WBAY, a "toll broadcast" station of the American Telephone and Telegraph Company, began "time shared" operation on the 830 kHz (360 meter) channel in the New York City area on July 25, 1922.  Because of poor performance operations were switched to station WEAF.
Marconi perfected a parabolic antenna for use in short wave communication systems
1923: Patent for iconoscope
1924: Hull creates the 4-electrode tube
Begining in 1924, Professor Hidetsugu Yagi and his assistant, Shintaro Uda, designed and developed a sensitive and highly-directional multi-element antenna.
Alexanderson transmitted the first facsimile message across the Atlantic on June 5, 1924.
1926: Philo Farnsworth produced the first all-electronic television image.
Tellegen adds suppressor (fifth) grid to create the pentode
1927: Establishment of first short wave, transatlantic telephone link.
1928: Alexanderson gave first public demonstration of television on January 13, 1924.
The Detroit Police Department commenced regular one-way radio communication with its patron cars (2 MHz) on April 7, 1928.
1929: Vladimir Zworykin demonstrated a television receiver including his "kinescope" -- a special cathode ray tube.
1920 :

 KDKA, a small radio station in Pittsburgh begins broadcasting on November 2. The world's first commercial radio station, it is built in one of the taller buildings owned by the Westinghouse Co., and equipped with a 100w transmitter built by engineer Frank Conrad. The antenna runs from a steel pole on the roof to one of the powerhouse smokestacks. Broadcasting begins at 8:00 pm and continues until midnight with reports of the Harding-Cox presidential election returns. The news that Warren Harding has won the race marks a dramatic end to an historic day in America's broadcasting as well as political history. Westinghouse will continue with regular daily broadcasts, at first only from 8:30 to 9:30 in the evening. Financed by advertisements and the sale of 'Music Box' receivers, the programming will include musical concerts staged on the roof of the KDKA building, where the acoustics are optimal. KDKA's success, and the success of the stations that follow, lead the way to the development of broadcasting as an advertising medium.

 also...

 Through the first commercial radio station KDKA, RCA establishes an international message service with France, Germany and Argentina. Experimental radio stations are on the uprise in the U.S. as wartime constraints are abolished, and by the end of 1922 there will be over 500 licensed commercial broadcasting stations in the US, compared to the eight in operation only a year earlier.

 A year after Marconi opens the first British public radio station at Chelmsford, Essex, the British Post Office places a ban on the two half-hour daily broadcasts eminating from the six kilowatt transmitter. The broadcasts, one of them a concert by opera singer Dame Nellie Melba, have been widely enjoyed; nevertheless, the fear of commercialization of the new medium, coupled with the military's claim on uncongested airwaves, leads to the P.O.'s ruling that experimental broadcasts must be individually licensed.

 Russian immigrant David Sarnoff, commercial manager of the restructured American Marconi company known as RCA, reiterates a four year-old idea for marketing "radio music boxes." This time, Owen D. Young of General Electric listens, but the members of the RCA alliance are distracted by international concerns and only placate the young idea-man with a $2000 grant to develop a prototype.

 Ernst Belin works on and introduces wireless transmission of photographs

 An automatic exchange in Leeds makes it possible to complete local calls in Britain without the intervention of an operator. This is accomplished through the innovation of the dial telephone, which triggers electrical pulses that alert the designated line.

 1921 :

 Within a year after the first commercial radio broadcast in the US, the first sports events are transmitted over the radio waves, including tennis, boxing and baseball. These contests, along with musical programs, accelerate the popularity of radio entertainment so that by the end of 1921, eight radio stations are established and operating in the United States.

 In the attempt to consolidate the rights to radio parts and receivers, Westinghouse buys patents from American experimenters Edwin H. Armstrong and Lee de Forest, rivals themselves in certain patent suits. De Forest, an admitted failure as a businessman, sells his patents at bargain prices. Armstrong will become a millionaire. Both inventors reserve the right to sell equipment to amateurs, though - a provision which will plague the RCA allies (GE Westinghouse, AT&T). All across the country, the radio boom will see 'amateurs' cutting into their business by assembling their own receivers and transmitters.

 Medium-wave radio broadcasts are transmitted for the first time in the US as amateurs begin to discover the possibilities of short wave. A trial short wave broadcast is transmitted across the Atlantic to Britain, proving that it has long-distance potential as well. Interference in short wave transmissions will be reduced with the introduction of Franklin's directional antenna.

 Quartz crystal oscillators are built to bring added stability to the radio signal. The mineral prevents frequencies from overlapping at the receiver.

 The Marconiphone Crystal Junior V1 and V2 models are the first ready-made home radio sets to appear in Britain. They are distributed by the Marconi Company in response to the burgeoning popularity of radio, though many consumers still prefer to build their own receivers from scratch.

 1922 :

 Alexander Graham Bell dies in Nova Scotia on August 22. On the day of his funeral, every U.S. and Canadian telephone is temporarily disconnected to honor the man who revolutionized human communication.

 On August 28, WEAF in New York (later WNBC) becomes the first "toll" radio station when it broadcasts a commercial message during the 5:00 p.m. program. The Queensboro Corporation's ad for apartments in Jackson Heights on Long Island seems to work; there are reports of increased sales as a result, and commercials are thereafter a regular feature. If the commercial trend pleases advertisers and station managers, it causes some radio purists considerable despair. "What have you done with my child?" cries Lee De Forest, the inventor of the triode and a staunch individualist who is often called the "father of radio." "You have sent him out on the street... to collect money from all and sundry... [and] made of him... a stench in the nostrils of the gods of the ionosphere." Once stabilized, commercial radio thrives in the US, while advertisements on public-owned radio are banned for some time to come in Great Britain and France.

 The Marconi company gets permission from the British Post Office to broadcast musical programs - about 15 minutes' worth per week. Transmitted from the Marconi research station at Chelmsford, Essex, the first of these authorized broadcasts takes place on Valentine's Day, 1922. Soon thereafter, another experimental station is set up in London. Others follow, and as the British observe the growth of radio in the US, they realize the potential of broadcasting in their own country, as well as the need for its regulation. On October 18, 1922, the BBC (British Broadcasting Company, Ltd.) is established to monitor the development of the industry.

 also...

 The British Broadcasting Company (BBC) transmits the first regularly scheduled radio broadcasts intended purely for entertainment and certified with the government's official stamp of approval. Radio licenses are distributed by the British Post Office. In the meantime, American radio flourishes as 99 new stations open in the US during a single month.

 Good quality motion picture sound is produced when an optical sound track is placed on the edge of the film strip. One of the first commercial demonstrations of this new process is given by the Tri-Ergon company in Berlin.

 As the BBC takes the responsibility of controlling the British airwaves away from the Marconi monopoly, it is awarded exclusive broadcasting rights by the Post Office in an attempt to keep the number of transmitters in operation to a minimum. It will be at least three years until outlying localities will be granted the right to broadcast. The magnetophone, a Marconi-Sykes invention, will also be passed on to the BBC. This cumbersome but effective device allows more than one performer to speak into the same microphone, because it picks up sound from a short distance.

 1923 :

 American Charles Francis Jenkins and John Logie Baird develop ( 1923 - 1926 ) a working television system based on the Nipkow disk. The systems both produced a small, crude, orange and black but recognizable image.

 Philo T. Farnsworth ( 13 years old ) developed an electronic camera tube, similar tube to Zworykin's 'Iconoscope' named the 'Image Dissector'.

 Vladimir Zworykin patents the 'Iconoscope', an electronic camera tube based on A.A. Campbell-Swinton's proposal of 1911. By the end of 1923 he has also produced a picture display tube, the 'Kinescope'.

 also...

 Electronic engineer Vladimir Kosma Zworykin, a Russian immigrant working at the Westinghouse Electric Corporation in Pittsburgh, files for a patent on the iconoscope. This device, which is based on the use of an electronic analysis procedure, represents the first television transmission tube. The following year, Zworykin applies for a patent on the television receiver or kinescope. Together with the iconoscope, it forms the first truly all-electric television system, advancing beyond the electromechanical systems that operate with such devices as the Nipkow disc. An image is focussed onto a screen inside the iconoscope by an external lens, while a high-velocity electron beam scans it from the other side in a succession of horizontal lines. The picture signal is developed as the beam strikes the photoelectric cells of the screen, causing them to emit differing impulses based on the amount of light falling upon them. The information then is translated into a picture signal, and a similar process transmits the reconstructed image to the receiving screen. Westinghouse does not immediately grasp the importance of Zworykin's inventions, but he will impress RCA officials in 1929 with an improved system. His pioneering work in telecommunications earns Zworykin the well-deserved title "father of television". The kinescope will be used many years later, synchronized with a motion picture camera, to preserve television broadcasts. In 1933, an advanced version of Zworykin's system is used for a transmission from the Empire State Building in New York City. The resolution is 230 lines. Toward the end of his life Zworykin tells members of SMPTE that he is unhappy with the uses to which his discovery has been put.

 A portrait of King George V of England is successfully transmitted by French scientist Fournier d'Albe through wireless telephony. The image is first divided into 30 lines, and each line is further broken down into 20 squares. A grey scale letter code reflecting the individual degree of shading is then assigned to each square, and the codes are read off into a microphone. After 22 minutes, the face of King George is transmitted as a series of dots.

 The A.C. Nielsen Company is founded. Nielsen's market research is soon being used by companies deciding where to advertise on radio.

 Westinghouse, General Electric, RCA, and AT&T entered into television research.

 The cumbersome, stationary carbon granule mike is replaced by a model that allows the performer complete freedom of movement while recording. The 'ribbon' microphone, designed with a strip of aluminum suspended between two magnetic poles, becomes a standard studio item.

 Dundee, Michigan is the site of the first cable radio service. The cost to subscribers is $1.50 per month.

 The National Association of Broadcasters (NAB) is organized by Chicago automobile financier Eugene F. McDonald, Jr. The founder of Zenith Radio Corporation, the firm licensed by Edwin Armstrong to produce radio sets using his patents, McDonald sets himself up as the president of the new association.

 The Burndept Ethophone V Portable is introduced to the consumer. Britain's first portable radio, it is designed to resemble a suitcase.

 Guglielmo Marconi undertakes major experimentation in shortwave wireless technology aboard his yacht, the Elettra. His findings will be a critical step forward in the development of ship-to-ship and ship-to-shore communication.

 Phonofilm is a sound-on-film system introduced by Lee de Forest, opening the way for "talkies." By 1925, 30 cinemas in the eastern US will be equipped for sound. However, silent films will dominate until Al Jolson inspires mass public acceptance with his 1927 musical "The Jazz Singer."

 1924 :

 Western Electric Corporation patents electrical sound recording. In the same year, Chester W. Rice and Edward W. Kellog of General Electric patent a dynamic loudspeaker that takes the place of headphones. They are also at work on an amplifier that can supply one watt's worth of power to the speakers. The Radiola Model 104 is commercially introduced the following year.

 John Logie Baird is the first to transmit a moving silhouette ( mask ) image, using a mechanical system based on Paul Nipkow's model.

 Two and a half million radio sets in the USA

 R. Ranger at RCA achieves the first transmission of a photograph from the US to Britain. His method involves placing a print on a cylinder that rotates while being scanned by a light beam.

 The moving coil loudspeaker is patented by Rice and Kellogg of GEC. Cutting down audio distortion significantly, these loudspeakers will provide high-quality audio for consumers in the following year.

 A short wave "beam" system transmits the first direct wireless link-up from Cornwall, England, to Cape Town, South Africa. "We speak across space and some day we shall see as we speak," is the famous message predicting the advent of television.

 Large towns in Britain may now tune into one of the eleven new radio transmitters that have been installed to supplement the broadcasting range of the main stations. 70% of the British public is now within range of good, clear radio transmission.

 1925 :

 Vladimir Zworykin takes out the first patent for colour television, although electronic colour systems are not fully developed until 25 years later.

 Commercial picture facsimile radio service across the USA

 Film producer Louis Blattner, designs the first recorder using magnetised tape instead of wire. Called the Blathnerphone, based on the German patents of Dr Kurt Stille. It is originally employed to synchronise sound to film at Elstree Studios in London

 Edwin Howard Armstrong, one of America's primary contributors to the technical development of radio, begins research on eliminating static that will result, eight years later, in the revolutionary technique of frequency modulation (FM). Armstrong will face unanticipated resistance from David Sarnoff and RCA, originally supporters of his work, when he introduces FM. The radio industry will be heavily invested in maintaining the status quo of equipment, and RCA's television interests will compete with FM for the upper frequencies.

 British physicist Edward Appleton of Cambridge University discovers that radio waves are reflected from the upper atmosphere as high as 310 miles from the ground. This fact will prove crucial to the development of radar.

 BBC initiates twin-wave radio broadcasting that allow the simultaneous transmission of two programs on different wavelengths. The approaching obsolescence of crystal sets becomes apparent because of their inability to pick up more than one wavelength, and their dependence on a transmitter located nearby.

 The Daventry wireless station in Britain is the most efficient and largest of its kind in the world. Having a transmission radius of 100 miles, it is the first to employ the new long wavelength technology. Using the power house and zinc earthing system, it supports the antenna with 50 ft twin triangular steel masts.

 The 3-25 megahertz wavelength that has been used solely by amateur broadcasters is now discovered by shortwave enthusiasts. Shortwaves prove to be perfectly suited to long distance communication, as they bounce repeatedly between the ionosphere and the surface of the earth.

 Edwin Howard Armstrong invents frequency modulation - FM - as a technique of eliminating radio static. Ultimately, he sues RCA over an infringement on his patent for FM. In 1954, in poor health, with most of his money gone, and a discouraging history of losses in patent suits, he commits suicide.

 1926 :

 Scottish television pioneer John Logie Baird uses a doll's head to demonstrate the mechanical scanning ability of a prototype television to 50 scientists in his Soho laboratory in London. They see flickering facial features as the light passes through spiral holes in a rotating disc in front of a photoelectric cell. The cell converts the light into an electrical signal which is then processed for degrees of intensity, and converted into a beam. Projected through holes in a second rotating disc, the beam is subsequently translated into a reconstruction of the image on a screen.

 NBC ( National Broadcasting Company ) is formed by Westinghouse, General Electric and RCA.

 Canadian experiments with mechanical television start in Montreal.

 Commercial picture facsimile radio service across the Atlantic Ocean

 The formation of the National Broadcasting Company (NBC) marks a turning point in the development of commercial radio and television, lifting it forever out of unregulated chaos and into the national scene. Founded by David Sarnoff, general manager of RCA, the new company resolves the patent disputes between members of the radio group (RCA, GE, Westinghouse, United Fruit) and AT&T, as well as the monopoly charges brought by the Federal Trade Commission. Formally established on July 7 with the signing of twelve separate documents, NBC will be owned jointly by RCA, GE and Westinghouse. It will lease AT&T's network of wires, and acquire its stations and air time. These include WEAF in New York, the core of the new network, sold to RCA for $1 million ($8 million of which is a "good will fee"). AT&T's desire to discontinue active programming while maintaining a lucrative position in the field is realized and, with nine affiliated stations, the first broadcasting network is born.

Warner Brothers launches their Vitaphone synchronized audio disc and film system in the US. 'Don Juan' is the first feature film to utilize the system, although only the musical score is carried on the 16 inch , 33.5 rpm discs. The 'talkies' craze will be initiated by their next production, 'The Jazz Singer', which stars the improvisational Al Jolson and includes dialogue as well as music on its soundtrack.

 The triode radio wave amplifier is rendered obsolete by the tetrode, invented by H.J. Round of the Marconi Company. The tetrode or grid valve resolves the static interference problem and boasts a superior high frequency reception. Marconi Company and GEC begin distribution in Britain. It will be a year before the amplifier is sold in the US.

 As the BBC becomes a public corporation, the newspapers lift previously imposed restrictions on the live coverage of sports events.

 1927 :

 The BBC ( British Broadcasting Corporation ), CBC ( Columbia Phonographic Broadcasting System ) later CBS, ( Columbia Broadacsting System ) are founded.

 Commercial transatlantic telephone service becomes available January 7, 1927. The first phone call takes place between the editor of the London Daily Mail on Fleet Street and his New York correspondent. Because technology has not yet resolved the problems involved in building functional underwater telephone cables, the service must rely on a powerful shortwave radio transmitter set up by the British Post Office. Rates are high: the journalists' conversation costs £15 ($75) for every three minutes.

 After five years of research, 21 year-old Utah engineer Philo T. Farnsworth demonstrates the first working electronic television system, equipped with the Farnsworth orthicon or 'image dissector tube'. This device electronically implements the mechanical Nipkow Disc principle, breaking an image down into light particles which are then transmitted and reconstructed at the receiving end.

 Congress passes the Radio Act of 1927. The law is concerned in great part with derailing the trend towards a broadcasting monopoly, but it also establishes the Federal Radio Commission (FRC) to allocate and regulate the use of the airwaves. The language of the law defines 'radio' as any communication transferred by electrical energy without the use of wires, thereby including television in its scope.

 John Logie Baird creates the first videodisc system fifty years before its commercial inception. The discs, based on existing phonograph technology, rotate at 78 rpm and have the ability to capture and reproduce hazy images when played on a gramophone and connected to a Baird receiver. The bandwidth is 5 kh and the images, though barely recognizable, are reproduced at 12.5 fps at a resolution of 15 points per horizontal line, 30 lines altogether. During the thirties, several copies will be sold by Selfidge's department store in London. However, the mechanical TV system goes into obscurity when the BBC decides to discontinue the product in 1936.

 Pictures of Herbert Hoover, U.S. Secretary of Commerce, are transmitted 200 miles from Washington D.C. to New York, in the world's first televised speech and first long-distance television transmission.

 also...

 The Bell System employs Baird's television system to send the first long distance television transmission in the US. The demonstration takes place in the New York laboratories of Bell Telephone. The president of AT&T, Walter S. Gifford, gathers together a large group of people to view the televised image of Herbert Hoover, then Secretary of Commerce and a presidential hopeful, in his Washington, DC office. Hoover's voice is simultaneously transmitted over telephone wires. A serious problem delaying major development in television at this time is that of frequency resolution. A clear image will require a frequency band of four million cycles, compared to the 400 cycles required for a clear audio transmission in radio.

 The United Independent Broadcasters (UIB), a 16-station radio network, is formed by promoter George Coats and former RCA executive Maj. Andrew J. White to rival David Sarnoff's NBC. Unable to handle the financial problems that almost immediately threaten their company's existence, Coats and White sell out to the Columbia Phonograph Company.

 The network, now renamed Columbia Phonograph Broadcasting System, debuts on September 18 with a key station, WOR, in New York. It will continue as a financially embattled concern until in 1928 Jerome Louchheim sells his controlling interest to William S. Paley, the man who will usher the company into its prime as CBS.

 Movietone offers newsreels in sound

 USA Radio Act declares public ownership of the airwaves

 Negative feedback makes hi-fi possible

 Boris Rtcheouloff applies for a patent for a video tape recorder (VTR).

 1928 :

 American inventor E. F. W. Alexanderson demonstrates the first home television receiver in Schenectady, New York. It consisted of a 3 inch screen and delivered a poor and unsteady picture.

 On May 28, 1928 the first television station WGY began broadcasting in Schenectady. Sets were built and distributed by General Electric in Schenectady.

 The world's first television drama, 'The Queen's Messenger' is broadcast, using mechanical scanning.

 Station W2XBS, RCA's first television station, is established in New York City, creating television's first star, Felix the Cat.

 Holst and Tellegen of Philips in Holland introduce the pentode to improve radio reception. This five electrode valve becomes popular in both high and low frequency amplification.

 John Logie Baird transmits television via shortwave radio from his London laboratories across the Atlantic to New York . A doll's head and Baird's own face are faintly displayed on a two by three inch screen.

 John L. Baird demonstrates a colour television system using a modified Nipkow disk.

 Ulysses Sanabria introduces interlaced television scanning, a technique that reduces flicker in the transmitted image. When the top line of an image is scanned, the line that forms directly below it remains empty. As the scanning process continues, the still picture is scanned in alternate lines, and the next picture that is transmitted scans into the previous picture's empty lines. The meshing of these interlaced fields forms a complete image frame, and the speed with which the screen phosphors decay works with the eye's inclination to meld disparate images together. The result is a sense of continuous motion from discontinuous information.

 William S. Paley invests in the Columbia Phonograph Company ( later CBS ), the fledgling NBC competitor founded one year ago. The network has weathered a very shaky start, avoiding bankruptcy several times before Paley, a cigar company advertising manager, provides his $500,000 transfusion. He has raised the money through a windfall family inheritance and by selling some of his stock in Congress Cigar. Paley first recognized the potential of commercial broadcasting in 1927 when cigar sales in his father's company soared after he advertised on Philadelphia's 225-watt station WCAU. Though criticized for spending $50 a week for the spots, Paley was undeterred in his vision. Within a year he is president of a 22-station network.

 Eight years after Nasavischwilly first proposed magnetic tape, Dr. Fritz Pfleumer of Austria receives German patent no. 500900 for his version - a paper strip covered with magnetizable iron powder - although it proves somewhat unsuccessful in experiments because of a low resistance level. Following laboratory experiments with steel-based wires and tapes, Pfleumer proposes plastic as an alternative, paving the way for a commercial magnetic tape. The "Magnetophones" marketed by the Germans will utilize plastic tapes. His original concept is eventually developed by chemists at BASF, who introduce a successful magnetic tape in 1932.

 The advent of talking pictures creates new friction between AT&T and RCA, the tensions from radio competition having only just recently eased. Much of the film industry adopts the AT&T/Western Electric sound-on-film process, leaving the RCA group (General Electric and Westinghouse) to catch up. Using an old GE recording process called Pallophotophone as a foundation, the group teams up with the Keith-Albee-Orpheum chain to establish RKO (Radio-Keith-Orpheum). In the ensuing scramble to garner power in the young motion picture industry, RCA takes over Pathe, and buys two music publishing companies.

 1929 :

 In London, John Logie Baird opens the world's first television studio, but is still able to produce only crude and jerky images. However, because Baird's television pictures carry so little visual information, it is possible to broadcast them from ordinary medium-wave radio transmitters.

 Bell Telephone Laboratories initiates the first color television transmission in a spectacular broadcast between Washington and New York, comprising a 50-line system that beams red, green and blue along three separate channels. Later transmissions this year will pave the way for modern color TV with three color signals transmitted over a single channel.

 Zworykin demonstrates the all electronic television camera and receiver.( Resolution 60 lines )

 The car radio is introduced in the USA

 In Germany, magnetic sound recording on plastic tape

 Bell Lab transmits stills in color by mechanical scanning

 General Squier invents the monophone in response to the congestion of US airwaves. This innovation makes it possible for telephone wires to carry radio signals, while consuming less power. As an added incentive, listeners can receive the signal on the same receiver they have used all along.

 The Blattnerphone, a magnetic tape recorder, is invented by Louis Blattner, a German film producer working in England. He uses his invention to for recording synchronized movie soundtracks.
1920: Westinghouse Electric and Manufacturing Company inaugurated commercial broadcasting service on KDKA in Pittsburgh on November 2, 1920 (some specs: transmission at a wavelength of 360 meters and a power of 100 watts).
1922: WBAY, a "toll broadcast" station of the American Telephone and Telegraph Company, began "time shared" operation on the 830 kHz (360 meter) channel in the New York City area on July 25, 1922.  Because of poor performance operations were switched to station WEAF.
Marconi perfected a parabolic antenna for use in short wave communication systems
1923: Patent for iconoscope
1924: Hull creates the 4-electrode tube
Begining in 1924, Professor Hidetsugu Yagi and his assistant, Shintaro Uda, designed and developed a sensitive and highly-directional multi-element antenna.
Alexanderson transmitted the first facsimile message across the Atlantic on June 5, 1924.
1926: Philo Farnsworth produced the first all-electronic television image.
Tellegen adds suppressor (fifth) grid to create the pentode
1927: Establishment of first short wave, transatlantic telephone link.
1928: Alexanderson gave first public demonstration of television on January 13, 1924.
The Detroit Police Department commenced regular one-way radio communication with its patron cars (2 MHz) on April 7, 1928.
1929: Vladimir Zworykin demonstrated a television receiver including his "kinescope" -- a special cathode ray tube.

1920
Marconi establishes the first short-wave radio link between London and
Birmingham, England on 20 Megacycles.
Although most experimenters and pioneers used the longer waves, Marconi
never did fully abandon his efforts to use the short-wave bands.
Westinghouse builds a 100 watt radio station in a little shack atop its
nine story factory in Pittsburgh... KDKA.
November 2, 1920, Frank Conrad and Donald Little broadcast election returns
from 8:00PM till after Midnight- an event that is credited with starting a
rush to build stations, and purchase receivers.
By late in the year, radio is being acclaimed as the newest form of
entertainment for the home.
The first superheterodyne circuit is announced by Armstrong.
Westinghouse purchases the Superhet patent from Armstrong, along with
several patents from Reginald Fessenden and Michael Pupin.
The 'C' battery is introduced to provide bias voltage. This helps the 'B'
battery last longer by reducing the amount of plate current needed on
tubes.
Radio experimenters spent over 2 Million dollars for radio parts in 1920.

1921
Westinghouse sets up stations WJZ in Newark, N.J. KYW in Chicago, Ill., and
WBZ in Springfield, MA.
A religious service was broadcast from Calvary Episcopal Church at
Pittsburgh through KDKA. The engineers wore choir robes, as not to distract
from the service.
Station WJC (soon to become WABC) in Newark, NJ broadcasts regular bedtime
stories.
David Sarnoff is named General Manager of RCA.
The Dempsey-Carpentier fight is broadcast on WJY. This fight is broadcast
to an audience estimated at 300,000. At nearly the same time as the fight
ended, the transmitter overloaded - and was described later as a 'molten
mass'. (Dempsey knocked out Carpentier in the Fourth round)
Westinghouse joins in the agreement with RCA, GE and AT&T. They share a
pool of over 2000 radio patents.
Speakers began to replace headphones for listening.
Attachments for holding headphones against the tone arms of phonographs are
being sold.
Signal strength is measured in terms of ..."I can hear it with the
headphones laying on the table".
There are 5 broadcasting stations on the air in December of 1921.
WJZ broadcasts a Baseball World series game, pitch by pitch, getting the
information by telephone.

1922
In September of 1922 there are 537 stations broadcasting.
Two frequencies are authorized for broadcasting...833 and 619 kc's.
A third frequency was added later in the year - 750 kc.
Approx. 100,000 radio sets are produced this year. Radio prices begin to
fall, as competition to market radio's grows.
WEAF in New York is the first to offer air time to advertisers. It was
August 28th, at 5:15 PM - an infomercial on the Hawthorne apartment complex
in Queens.
Edwin Armstrong invents the 'Super-Regenerative' receiver.
 

1923
US President Harding has a radio installed at the White House.
The first Network broadcast was made, as WEAF, WJAR and WMAF are linked by
phone.
New radios became obsolete in 3 to 6 months time.
Approx. 500,000 radio sets are produced this year.

1924
The present A.M. band is assigned. It spans 550 - 1550 kilocycles.
President Coolidge's cat is lost...and found with the help of Radio.
Over 1400 stations are now broadcasting.
It is estimated that over 3 million radio sets are in use in the United
States.
Baseball games are broadcast almost daily.
New radio's - superhets, reflex sets, TRF's, and neutrodynes are much more
complex, so a new industry begins to take shape - the radio repairman.

1926
The first 'light socket' powered sets are marketed.
RCA, Westinghouse and GE start a network...NBC, the National Broadcasting
Corporation.
A US court decides that the Secretary of Commerce has no power to regulate
broadcasting - only to issue licenses, and the chaos on the broadcast bands
grows as stations increase power to drown out the competition.
David Sarnoff is named vice president of RCA.
The BBC, British Broadcasting Corporation is granted a Royal Charter.

1927
Televisions are being sold in kit form.
The FRC, Federal Radio Commission begins to regulate broadcasting. Their
first act was to revoke all licenses, and then assign frequencies and power
levels.
The Columbia Broadcasting System - CBS - is started.

1928
Diode detectors receive consideration by radio designers.
Type 226 and 227 tubes with AC heaters are released by tube manufacturers.
AC Screen Grid tubes are announced towards the end of the year.

1929
RCA gains control of several important radio patents, and begins to license
manufacturers to use those designs. Prior to this, radio design was
somewhat stifled because no one could legally use the designs of many
important circuits.
Amos 'n' Andy becomes a series on NBC
A typical AC TRF receiver employs type 226 tubes in the RF and AF amps, a
227 as a detector, type 71A for the output and a type 80 in the power
supply.

1933: Armstrong awarded circuit patents which are the basis of frequency modulation (FM) systems: he had been working intensely on FM since 1925.
1934: On June 9, 1934, Armstrong demonstrated the superior noise reduction characteristics of FM by broadcasting an organ recital in both AM and FM.
Marconi demonstrates equipment for a maritime navigational system.
1935: Armstrong broadcasted the first regular frequency modulation (FM) programming.
1940: The Connecticut State Police began operating a two-way frequency modulation system in Hartford.
1946: First Bell mobile (manually patched) service at 150 MHz.
 

1930
The TRF, Tuned Radio Frequency receiver was still the leader, but many
superhet receivers were being made.

1931
RCA, The Radio Corporation of America markets the "Radiola 80", one of the
most famous of all receivers.
The first 'midget' sets are sold.
The radio building boom has begun to wane...as most consumers are now
purchasing complete sets, rather than kits.

1932
AVC, or Automatic Volume Control was introduced.
The first auto radios are sold. (you still had to stop and put up a
antenna.)
WFLA(AM)-WSUN(AM) in Clearwater, Fla., installs the country's first
directional antenna.

1933
Several Phonograph companies start labeling records "not licensed for radio
broadcast" as move to protect their alleged property rights.

1934
Armstrong develops his theory to use FM.
'All-Wave' receivers are a hit this year, bringing in radio from foreign
broadcasters.
WLW increases to a half million Watts of power.
The Federal Communications Commission (FCC) is created.

1935
The first metal tubes are released.
Over a million auto radios are installed this year.
Armstrong demonstrates FM.

1936
Most radios sold now employ an AFC circuit - Automatic Frequency Control.
'Automatic Tuning' (pushbuttons) are the years big hit.
Approx. 8 million sets are sold this year.
3 out of 4 families have a radio in the home.

1937
Cathode Ray tuning eyes (the Magic Eye Tube), Slide Rule tuning, and sleek veneered cabinets are the big features this year.
The dirigible, Hindenburg crashes in flames at Lakehurst, N.J. May 6th, 1937 - and the tragedy was captured in an incredible live radio
broadcast.
The NBC Symphony Orchestra is formed.

1938
Howard Hughes flies around the world and keeps in touch by radio.
Broadcasting standards for TV were announced, paving the way for commercial
television stations.
The power of radio is demonstrated by Orson Wells, and the "Mercury Theater
of the Air" - Panic is reported to be widespread as people believe the
earth has been invaded by "Martians... and we are in a "War of
the Worlds"

1939
TV is demonstrated at the New York Worlds Fair.
Edwin Armstrong is operating W2XMN - a 50,000 watt FM station at Alpine,
N.J.
The first Television sets are sold by several manufacturers.
Wind generators are sold to farms to keep their radio batteries charged.
The start of the European war renews interest in short-wave receivers.

1940
Jacks are provided on the back of new radios to plug in your TV's sound.
FM gains public interest as 'Noise Free', high fidelity broadcasting grows.
Amateurs lose the right to communicate with foreign operators as the war in
Europe builds.

1941
FCC authorizes FM broadcasting on 42-50 MHz.
13 million radio sets are made this year, and 130 million tubes.
Color TV was demonstrated for the first time.
30 commercial FM stations are now on the air.
The Japanese attack Pearl Harbor.
All amateur radio communication is halted by the war.

1942
The manufacture of radio sets was stopped due to the war, and manufacturers
switch to defense activities.
British mathematician and science fiction writer Arthur C. Clark suggests
using satellites to relay radio signals about 20 years before the first
satellite, Sputnik I was placed in orbit!

1943
Great strides are made in technology and manufacturing as radio is used in
the war.
Meanwhile at home, many receivers are remodeled with whatever parts are on
hand - as wartime shortages and aging radio sets combine for some creative
electronics repair.

1944
Over 30 million U.S. homes now had 57 million radio sets.
No receivers are being manufactured, although some spare parts are now
becoming available.
Germany makes use of short-wave radio for propaganda broadcasts.

1945
The FCC changes the FM band from near 50 Megacycles to the present 88 to
108 megacycles. This rendered many sets obsolete, and set back Armstrong's
development of FM as an alternative to AM. This may (!) have been the plan
all along by those involved with AM broadcasting.

1946
Lee Deforest grows increasingly unhappy with the state of broadcasting. To
him, radio had become 'a stench in the nostril of the gods of the
ionosphere.'
He addresses the National Association of Broadcasters at their annual
meeting in Chicago.
Table model radios are the big seller. Over 15 million sets are produced.
About half a million of those were FM receivers.
Selenium rectifiers begin to replace vacuum tube rectifiers.

1947
Radios are shrinking in size, and over 800 thousand FM receivers are
produced.
Miniature tubes, rectifiers, transformers, and printed circuit boards are
used.
John Bardeen, Walter Brattain, and William Shokley invent the Transistor.

1948
The FCC announces a three month freeze on new TV station applications. It
lasts nearly four years! TV picks up steam. 10 inch screens are the most
common.
The LP or Long Play phonograph was introduced.
The first Transistor is introduced to the public.

1949
4 million TV sets are produced, far exceeding projections.
10 inch screen TV's have dropped in price by a third since 1947 - from $300
to $200.
The 45 RPM record is introduced.
By the end of the year, there are 98 television stations and 2021 radio
stations on the air.
$628 million dollars is spent on radio advertising this year.

1950
People are talking about Transistors for the first time, saying they just
might replace the tube.
4 million TV sets are in use in the U.S. on January 1st.
10 Million TV sets are in use by December 31st.
Some 90 million radio sets are in use in the United States - an average of
2 radios for every home in the nation.
Regular color television transmission begins.
The Korean War begins. Shortages begin to develop for receiving equipment.

1951
108 TV stations are broadcasting.
The United States averages two radio sets in every home.
Color TV and UHF TV are talked about everywhere.
Over 5 million auto radios are produced, and over 13 million other radio
receivers..
Various conservation methods are used to get around shortages in
manufacturing of radios and TV's.

1952
The FCC's '3 month' freeze on new TV station applications, imposed in 1948,
is finally lifted.
21 million US homes had TV sets.
Sony markets the miniature transistor radio.
10 thousand Transistors are manufactured, mostly for government and
research.
Geoffrey W.A. Drummer proposes "electronic equipment in a solid block with
no connecting wires..." - The integrated circuit.

1953
326 TV stations are on the air.
Electronics looks like a good field to get in to.
The Voice of America steps up broadcasts to behind the 'Iron Curtain".
 

1954
Magnetic tape is demonstrated for recording television pictures by RCA.
Transistors begin to see widespread use

1955
Over 7 million Radio sets are produced. That number, although less than the
peak of Radio production in 1947 climbs steadily through 1961 when over 11
million sets are made in the US.
IBM invents the computer 'Hard Drive'

1958
Stereo Records reach the marketplace.
Hi-Fi Sound reproduction is a growing interest.

1959
Robert Noyce and Gordon Moore develop a silicon integrated circuit using
planar technology and diffused junctions.

1960
The manufacture of portable AM/FM or FM sets grows at 750 percent between
1960 and 1965.
The Tape Cart (Soon to become the 8-Track Tape) is introduced.
Echo I reflects radio signals back to Earth.

1961
FM Stereo Broadcasting is authorized.
Commercial production of IC's is begun by several companies.

1962
In an effort to produce color pictures on black and white sets, several
manufacturers reportedly tint the CRT blue on top, and green on the
bottom...
Portable AM receivers lead in production - over 5 1/2 million were made in
1962.
The satellite Telstar transmits video images across the Atlantic.

1963
The E.B.S. - Emergency Broadcasting System is developed. "This is a test of
the emergency broadcast system. The broadcasters in your area..etc.. etc.....this concludes this test of the emergency broadcast system."
Cassette tape is introduced.
The first communications satellite is placed in geo-synchronous orbit.

1964
Table and Clock radios are produced at over 3 million per year, a figure
that holds steady from 1960 to 1965.

1965
New Vacuum Tube receivers are almost non-existent as transistors have taken
over the market.
All told, between 1922 and 1965, over 300 million radio receivers were
manufactured in the United States.

1966
Component Stereo equipment grows in popularity.

1967
Dolby noise reduction is introduced.

1969
Astronauts send the first live pictures and audio from the moon.

1971
Intel builds the microprocessor, "a computer on a chip."

1972
New FCC rules bring community access television.
"Open Skies" allows any U.S. firm to have communication satellites.
Landsat I, the "eye-in-the-sky" satellite, is launched.

1973
September 19th, a 'Pirate Radio' station begins to broadcast from a ship
anchored some 3 miles offshore of Cape May, N.J. It was shut down the same
day by the FCC.
The microcomputer is born in France.

1976
Ted Turner delivers his programming nationwide by satellite.

1977
There are some 205 million FM receivers in use in the United States. 95% of
the nation's homes had an FM receiver.

1978
PBS delivers programming by satellite.

1979
The FCC reports there are 8,651 radio stations on the air. 4,549 AM, and
4,102 FM. Over 400 million receivers are in US homes and automobiles.
In Japan the worlds first cellular phone network starts.

1980
Intelsat V relays 12,000 phone calls, 2 color TV channels.

1981
The IBM PC.

1982
A.M. Stereo is first authorized in the United States. 5 competing systems
struggle for dominance - as the FCC refuses to settle on a standard.

1983
Cellular phone network starts in U.S.

1984
Conus relays news feeds for stations on Ku-Band satellites.
A television set can be worn on the wrist.

1985
Sony builds a radio the size of a credit card.
U.S. TV networks begin satellite distribution to affiliates.

1986
The first 'dial-up' remote control system for a transmitter is introduced
by Gentner.
HBO scrambles its signals.

1987
Half of all U.S. homes with TV are on cable.

1988
FCC allows 'Short Spacing' of FM stations

1991
FCC approves expansion of the AM broadcast band. The change adds from
1605-1705 kHz.

1992
As of November 30th, 1992 the FCC reports 4961 AM stations, 4766 commercial
FM stations, and 1585 Educational FM stations, for a total of 11,312 radio
stations on the air in the United States. There are also 1509 television
stations broadcasting.
New station ownership rules go into effect - a single group may now own up
to 18 AM and 18 FM broadcast stations.
The Digital Compact Cassette (DCC) is introduced to the consumer market.
'USA Digital Radio' conducts its first 'on-air' tests of their in band on
channel A.M. digital audio broadcasting in Cincinnati, OH.

1993
FCC selects the Motorola C-QUAM system of AM stereo transmission as the US
standard - Ten Years after AM stereo was first authorized. The lack of an
approved standard greatly hindered the development of this mode of
broadcasting.

1994
The top format for U.S. Commercial radio is Country - 2642 stations.
Adult Contemporary is number two with 1784, News/Talk has 1028, and
Religious stations are fourth with 926 stations.
Rock is programmed by 721, Oldies 714, Spanish/Ethnic has 470 and Adult
Standards is programmed by 435.
Rounding out the top ten are Top-40 with 358 and Urban with 328.
Denmark begins on air testing of the Eureka 147 method of Digital Audio
Broadcasting on 237 MHz.

1995
The first broadcast station in the expanded band signs on. WJDM - Elizabeth
NJ at 1660 kHz.
The average U.S. home has 5.6 radio receivers.
There are an estimated 584,900,000 radio receivers in use.
The BBC - British Broadcasting Corporation - begins introductory DAB
service.

1996
Digital Audio Broadcasting begins in Sweden from four transmitters
utilizing Eureka 147.
The U.S. Congress mandates that the FCC collect over 152 million dollars in "regulatory Fee's" from broadcasters in 1997.
 

1997
January 1st the E.A.S., Emergency Alert System goes 'on-line' in broadcast
stations - replacing the aging technology of the E.B.S. - the Emergency
Broadcasting System.
The FCC issues only two licenses for Digital Audio Radio Service (DARS) - by Auction! Only the four original applicants from 1992 are allowed to bid. American Mobile Radio Corporation and Satellite CD Radio, Inc. are the winners.
In comments on the action, the FCC said it "could not entirely rule out the possibility of a major adverse impact" to traditional local broadcasters.

1933: Armstrong awarded circuit patents which are the basis of frequency modulation (FM) systems: he had been working intensely on FM since 1925.
1934: On June 9, 1934, Armstrong demonstrated the superior noise reduction characteristics of FM by broadcasting an organ recital in both AM and FM.
Marconi demonstrates equipment for a maritime navigational system.
1935: Armstrong broadcasted the first regular frequency modulation (FM) programming.
1940: The Connecticut State Police began operating a two-way frequency modulation system in Hartford.
1946: First Bell mobile (manually patched) service at 150 MHz.

 
 

 1930 :

 NBC is granted an experimental broadcast licence.

 The first commercial is televised by Charles Francis Jenkins, who is subsequently fined by the U.S. Federal Radio Commission.

 A theatrical show transmitted by BBC is the first synchronized sight and sound television talkie broadcast. Viewers at Hendon, North London, see and hear the transmission from Coliseum Theatre in London's West End.

 TVs based on British mechanical system roll off factory line - The Plessey Radiovisor

 The ABC ( Australian Broadcasting Company, later Commission, later Corporation ) is founded.

 An audience pays to watch television at the London Coliseum.

 American Philo Farnsworth patents electronic television.

 AT&T experiments with the picture telephone

 1931 :

 Rene Barthelmy demonstrates mechanical television at the Ecole Superieure d'Electricite in Paris.

 Henri de France achieves television transmission from Toulouse to Le Havre, France.

 Canada's first television station, VE9EC, starts broadcasting in Montreal.

 Ted Rogers, Sr. receives a licence to broadcast experimental television from his Toronto radio station.

 CBS, the Columbia Broadcasting System, puts its first experimental television station on the air.

 RCA begins experimental electronic transmissions from the Empire State Building.

 Londoners gather at the Metropole Cinema and pay to view the first outside television broadcast: the classic Derby horserace.

 Television is introduced to the Russians, as Muscovites receive their first transmissions over homemade receivers.

 An early Christmas gift for the nation comes in the form of regular television broadcasts which are initiated on December 23.

 The one-hour programs, which originate from the West Coast at station W6XAO, provide a daily dose of movies on VHF.

 NBC experimentally doubles transmission to 120-line screen

 1932 :

 CRBC ( Canadian Radio Broadcasting Commission ), is founded to be superseded by the CBC in 1936.

 Fully electronic television is demonstrated for the first time.

 RCA starts an NBC television station in the Empire State Building.

 The BBC takes over the Baird Company's role in developing television in Britain.

 Rouben Mamoulian's film 'Becky Sharp' is first 3-strip Technicolor feature

 Disney adopts a three-color Technicolor process for cartoons

 Stereophonic sound in a motion picture, 'Napoleon'.

 1933 :

 Western Television Limited's mechanical television system is toured and demonstrated at Eaton's stores in Toronto, Montreal and Winnipeg.

 Edwin Armstrong invents Frequency Modulation ( FM ), but its real future is 20 years off

 1934 :

 An evening news program, 'Spiegel des Tages' ( Mirror of the Days ), produced by Reichs Rundfunk, uses a mobile television unit to record portions of its daily broadcast.

 Half of the homes in the United States have radios

 The Communications Act of 1934 creates FCC in USA

 Associated Press starts wirephoto service

 1935 :

 William Hoyt Peck of Peck Television of Canada uses a transmitter in Montreal during five weeks of experimental mechanical broadcasts.

 RCA pledges millions of dollars towards the development of TV.

 Germany opens the world's first three-day-a-week filmed television service.

 PTT, the Post and Telecommunications Authority in France, begins regular television transmissions from atop the Eiffel Tower.

 Eastman Kodak markets Kodachrome film

 In Germany, audio tape recorders go on sale

 In USA, all-electronic VHF television comes out of the lab

 1936 :

 There are about 2,000 television sets in use around the world.

 The British Post Office issues the first broadcast television transmission standard.

 High-definition television broadcasts are initiated at the BBC with a sophisticated new system by EMI involving the Emitron, a camera tube that can emit 25 unflickering pictures per second on a 405-line screen. This marks a vast improvement over Baird's mechanical system, which uses only 240 lines.

 Radio manufacturers in the US adopt a 441 scanning line standard for television.

 PTT the Post and Telecommunications Authority in France, begins daily broadcasting of television at 455 scanning lines in September.

 An NBC mobile television transmission unit experiments with pictorial news broadcasting in New York. The unit consists of two large buses, one housing a field studio, the other a mobile transmitter that beams the signal back to the main transmitter in the Empire State Building.

 TV cameras record the coronation of King George VI, transmitting from various points along the procession, while the service in Westminster Abbey is broadcast by radio. It is the most intricate production in broadcast history to date.

 The Olympic Games in Berlin are the first to be broadcast on television. One of the technicians working on the broadcast is Klaus Landsberg, later to guide technical development for Paramount at KTLA in Los Angeles.

 1938 :

 Allen B. DuMont forms the DuMont television network to compete with RCA and manufactures the first all-electronic television set for sale to the North American public.

 The radio drama, 'War of the Worlds', by Orson Welles' Mercury Theatre Players causes national panic

 W. Fleichsig develops the shadow mask tube for color TV, soon to be a staple in color broadcasting.

 The Dominion Theater in London is the site for the first demonstration of high resolution color television by John Logie Baird. Using a large screen ( 9 x 12 ft. ), Baird is also able to transmit a live broadcast from the Crystal Palace. Commercial development of color television is frustrated though, by Baird's insistence on using mechanical, not electronic, scanning systems.

 Chester Carlson invents Xerography

 1939 :

 On April 30, Franklin D. Roosevelt inaugurates commercial television with his appearance on the first public broadcast, viewed by thousands at the New York World's Fair. FDR is the first President to go on a television broadcast. His appearance is followed by that of RCA's David Sarnoff who announces the launch of the company's first commercial TV set, it has a 30cm (12in) screen and sells for $625.

 CBS ( Columbia Broadcasting System ) begins television broadcasting this year as well.

 The first major display of electronic television in Canada takes place at the Canadian National Exhibition in Toronto.

 Television sets range in price from $200 to $600.

 Baseball is televised for the first time.

 Mechanical scanning television system abandoned

 Convinced that television theater is the wave of the future, Professor Fischer of the Swiss Federal Institute of Technology creates the Eidophor, a large-screen TV projector.

 TV transmitters are shut down in Britain when war is declared against Germany, to eliminate the danger of providing the enemy with navigational beacons. The BBC abruptly stops broadcasting in the middle of a Mickey Mouse cartoon on September 1, resuming at that same point when peace returns in 1945.

 Australia Calling ( later Radio Australia ) begins transmission to offset overseas propaganda broadcasting.

 1940 :

 Dr. Peter Goldmark of CBS introduces a 343-line colour television system for daily transmission, using a disc of three filters ( red, green and blue ), rotated in front of the camera tube.

 The FCC decides US television will have FM sound as Edward Armstrong, the creator of frequency modulation, finally gets the support for which he has struggled so assiduously.

 CBS demonstrates its field sequential color television system to NTSC engineers. The system is based on a quickly spinning color wheel. The FCC will adopt this system in 1950, but three years later the decision will be revoked in favor of the RCA color system.

 Fantasia introduces stereo sound to American public

 1941 :

 CBS and NBC start commercial transmission; The US enters WW II following the attack on Pearl Harbour on December 7

 1942 :

 Kodacolor process produces the color print

 1941 :

 North America's current 525-line / 30-pictures-a-second standard, known as the NTSC ( National Television Standards Committee ) standard, is adopted.

 NBC and CBS are granted commercial broadcast licences.

 All radio and televison enterprise is devoted to the war effort

 1946 :

 Television enjoys a resurgence as the US lifts its wartime ban on TV manufacture, and the BBC resumes broadcasting.

 6,500 television receivers are sold in the United States.

 NBC and CBS demonstrate rival colour systems.

 The world's first television broadcast via coaxial cable is transmitted from New York to Washington D.C.

 Automobile radio telephones connect to telephone network

 1947 :

 A permanent network linking four eastern U.S. stations is established by NBC. On June 3, Canadian General Electric engineers in Windsor receive the first official electronic television broadcast in Canada, transmitted from the new U.S. station WWDT in Detroit.

 Bob Hope participates in the first commercial broadcast in the Western US. The station, owned by Paramount, is W6XA0 in Los Angeles ( later to be called KTLA ). The broadcast is sponsored by Ford Motor Company's Lincoln division.

 KTLA in Los Angeles broadcasts the first home shopping television show.

 Hungarian, Dennis Gabor describes principles of holography

 1948 :

 The BBC begins the first regular British television broadcast, called 'The BBC Newsreel'.

 Television manufacturing begins in Canada. The television audience increases by 4,000 percent this year, due to a jump in the number of cities with television stations and to the fact that one million homes in the U.S. now have television sets.

 The U.S. Federal Communications Commission puts a freeze on new television channel allocations until the problem of station-to-station interference is resolved.

 The Gerber television broadcasting standard is adopted in Europe, featuring 625 scanning lines at 25 frames per second.

 Network television in the US begins, with separate networks on the East and West coasts.

 The first cable television systems appear in the US.

 1949 :

 The first Emmy Awards are presented, and the Canadian government establishes an interim policy for television, announcing loans for CBC television development.

 An RCA research team in the U.S. develops the Shadow Mask picture tube, permitting a fully electronic colour display.

 The presidential inauguration is broadcast for the first time; in 1957 it will be videotaped for the first time.

 First introduced 20 years earlier, color television is finally available commercially. Developed by engineers at Pye, it is demonstrated for the public at London's Olympia.

 In USA, Community Antenna Television is introduced, forerunner to cable

 1950 :

 Cable TV begins in the U.S., and warnings begin to be issued on the impact of violent programming on children. European broadcasters fix a common picture standard of 625 lines.

 By the 1970s, virtually all nations in the world used 625-line service, except for the U.S., Japan, and some others which adopted the 525-line U.S. standard.

 Sales of television receivers in the US exceed $1billion. There are more than 100 TV stations operating in 38 states. The census shows only 5 million American homes have television sets, but sales figures show that 8 million are in use. 45 million US homes have radio at this time.

 Transmitters are installed atop the Eiffel Tower and the Belfry in Lille. The first regular television transmissions begin in France on April 25, 1950.

 RCA's Vidicon TV camera is the first to use a photoconductive tube. The Vidicon is more adaptable and less expensive than previous TV cameras.

 CBS initiates regular commercial color TV broadcasting with a one-hour program featuring Ed Sullivan and Arthur Godfrey.

 WOR in New York broadcasts the first pay TV program.

 1951 :

 The first colour television transmissions using the Peter Goldmark colour system begin in the U.S. For technical reasons, the several million existing black-and-white receivers in America cannot pick up the 'field sequential color television system' programmes, even in black-and-white. Colour sets go blank during television's many hours of black and white broadcasting. The experiment is a failure and colour transmissions are stopped.

 In the US, Armour Research demonstrates a crude VTR - Video Tape Recorder - to Alexander Poniatov and Ampex executives.

 Ampex immediately begins work on one of its own in Redwood City, California. The team of engineers includes Ray Dolby, destined to make his own impact on the sound industry. After several years of work and many dead ends, the resulting VR 1000 is marketed in 1955, with great success.

 A parallel effort to develop the required tape goes on at 3M Corporation. 3M's first Scotch 179 reel is 2 in. wide, nearly 800 m long, and weighs 10 kg.

 The U.S. sees its first coast-to-coast transmission in a broadcast of the Japanese Peace Conference in San Francisco.

 1952 :

 John Mulloin and Wayne Johnson of the Bing Crosby Enterprises laboratories make the first high-definition video recording on magnetic tape. The one-inch (2.5 cm) tape uses eleven tracks for pictures and one for sound and is three times cheaper than any comparable process.

 Cable TV systems begin in Canada. On September 6, CBC Television broadcasts from its Montreal station; on September 8, CBC broadcasts from the Toronto station.

 The first political ads appear on U.S. television networks, when Democrats buy a half-hour slot for Adlai Stevenson. Stevenson is bombarded with hate mail for interfering with a broadcast of 'I Love Lucy'.

 Eisenhower, Stevenson's political opponent, buys only 20-second commercial spots, and wins the election.

 Television sets in American homes pass the 22 million mark

 1953 :

 A microwave network connects CBC television stations in Montreal, Ottawa and Toronto. The first private television stations begin operation in Sudbury and London.

 Britain has its first public showing of color TV when the BBC broadcasts the coronation of Queen Elizabeth II to the Great Ormond Street Hospital for Children in London. The CBC beats U.S. competitors to the punch by flying footage across the Atlantic.

 'TV Guide' is launched.

 The National Television Systems Committee ( NTSC ) of the US develops a set of compatible technical standards for black and white and color transmissions, making it possible to receive color broadcasts on black and white sets The system is adopted in America, Japan, and many other countries in the Americas. Engineers joke that the acronym stands for 'Never The Same Color'.

 Japanese television goes on the air for the first time.

 Eduard Schueller applies for a patent on a helical video tape recorder with two heads.

 Half the homes in the United States have television sets.

 1954 :

 Commercial colour broadcasting begins in United States using the NTSC standards.

 RCA produces the first color television sets in the US, but color reception is still erratic. RCA will have the color TV field to itself until 1959, when patent suits are settled and Zenith and others enter the market.

 Magazines now routinely offer the homemaker tips on arranging living-room furniture for optimal television-viewing pleasure.

 Frozen TV dinners are marketed for the first time.

 3D television broadcasts begin in Mexico. Glasses for viewing the telecasts in 3D cost 25 pesos.

 1955 :

 NBC's popular children's program 'Howdy Doody' becomes the first all-color television series.

 The predecessor to the Trinitron television is developed at Paramount Pictures.

 Paul Weimer of RCA describes a single tube color camera.

 Britiain gets its first commercial television channel. ITV ( Independent Television ) serves an audience of 12 million. The first commercial is for toothpaste.

 Dwight D. Eisenhower is the first president to broadcast his press conferences on television. These early TV press conferences are screened and reviewed before they are released for broadcast.

 1956 :

 Ampex markets the first quadruplex, transverse scan video tape recorder. It uses two-inch tape.

 CBS' 'Douglas Edwards and the News' is the first taped TV program to be broadcast. The program is taped so it can be rebroadcast to the west coast three hours after it is seen in the east.

 Henri de France develops the SECAM ( sequential colour with memory ) procedure. It is adopted in France, and the first SECAM colour transmission between Paris and London takes place in 1960. In 1967 it will be adopted in France and the USSR.

 American engineers joke that the acronym stands for 'System Essentially Contrary to American Methods'.

 Several Louisiana congressmen promote a bill to ban all television programmes that portray blacks and whites together in a sympathetic light.

 Television Comes to Australia for the 1956 Olympic Games.

 By the end of 1956, 13 video tape recorders have been installed at ( US ) TV stations.

 1957 :

 The first VTR equipped remote trucks appear.

 Tape is interchanged from one VTR to another for the first time.

 The first quadruplex color VTR is demonstrated by Ampex, and called the VR 1000B. In 1963 a transistor version will be marketed under the name VR 110.

 Mechanical Video Tape editing begins. The process involves pouring magnetically sensitive salts on the service side of the tape. Then the editor looks at the tape through a microscope. Once the signal characteristics have been gleaned and the edit point determined, a transverse slice is made with a demagnetized razor.

 Chromakey, an electronic process using one primary color to matte a second video signal, is used for the first time on CBS' broadcast of 'Cinderella'.

 Philips produces a new TV camera tube, the Plumbicon. An improved version of its predecessor, the Vidicon, it becomes universal in color TV camera design

 1958 :

 SMPTE forms the Videotape Recording Committee to establish standards.

 CBS broadcasts 'The Red Mill', the first full length program edited on videotape.

 US Television advertising revenues exceed $1 billion.

 Color is synthesized from a monochrome television set in the first 'flicker color' broadcast.

 John Silva and Roy White, under the direction of Klaus Landsberg, design the Telecopter, a helicopter equipped with a vidicon camera and microwave transmission equipment. The signal is relayed to a fixed wing aircraft, which in turn passes it to the transmitter on Mt. Wilson near Los Angeles. From there the signal is routed, by microwave, to master control at KTLA in Hollywood.

 'The Betty Freezor Show' is the first TV program to be taped in color. It is broadcast by WBTV of Charlotte, North Carolina only two hours after it is recorded on 1/2 in. (1.25 cm) videotape, with only a slight deterioration of the picture.

 The CBC's microwave network is extended from Victoria, B.C. to Halifax and Sydney, Nova Scotia, to become the longest television network in the world.

 Pope Pius XII declares Saint Clare of Assisi the patron saint of television. Her placement on the television set is said to guarantee good reception.

 1959 :

 Sony is the first company to market a transistorized television. This black and white portable set will be followed in one year by a color model. The color model will use a picture tube designed by Ernest Lawrence, inventor of the cyclotron, a device essential to the design of the first atomic bombs.

 CBC Radio-Canada Montreal producers go on strike.

 1960 :

 The Nixon-Kennedy debates are televised, marking the first network use of the split screen. Kennedy performs better on television than Nixon, and it is believed that television helps Kennedy win the election.

 Sony develops the first portable battery operated, all-transistor television receiver, making televisions lighter and more portable.

 Ninety percent of American homes now own television sets, and America becomes the world's first 'television society'. There are now about 100 million television sets in operation worldwide.

 First ruby laser built by Theodore Maiman

 First successful hologram produced

 1961 :

 The Canadian Television Network (CTV), a privately owned network, begins operations.

 The Dodd hearings begin in the U.S., examining the television industry's 'rampant and opportunistic use of violence'.

 1962 :

 The Telstar television satellite is launched by the U.S., and starts relaying transatlantic television shortly after its launch. The first programme shows scenes of Paris.

 A survey indicates that 90 percent of American households have television sets; 13 percent have more than one.

 There are 951 VTRs in use worldwide.

 Toshiba demonstrates a helical VTR.

 JVC of Japan sells the first helical VTR.

 The first solid state VTRs come from RCA and Sony.

 Ampex demonstrates electronic video tape editing.

 Transatlantic television broadcasting is possible for the first time when the satellite Telstar is put in orbit. AT&T uses Telstar to transmit an image from Maine to Cornwall in Britain. The event captures the imagination of the American public, as soon evidenced by a popular Top-40 song named after the satellite.

 Professor Walter Bruch in Germany develops the PAL - Phase Alternate Line - system of color television transmission. The system's first use is in Germany in 1967. PAL will have several variants, and will be accepted in Italy, Britain and many other European and Asian countries.

 ABC Television ( US ) begins broadcasting in color for three and a half hours a week. NBC is now broadcasting 68% of its programming in color. CBS broadcasts only in black and white. By 1967, all three networks will be broadcasting entirely in color.

 1963 :

 On November 22, regular television programming is suspended following news of the Kennedy assassination. Two days later, live on television, Jack Ruby murders Lee Harvey Oswald, Kennedy's suspected assassin.

 Kennedy's funeral is televised the following day. 96 per cent of all American television sets are on for an average 31 hours out of 72 during this period watching, many say, simply to share in the crisis.

 Rectangular screen color TVs are introduced to the American consumer.

 Polaroid introduces instant color film

 1964 :

 BBC2 begins broadcast service, operating on UHF ( ultra high frequency ) with a 625 line picture. Britain's two other channels broadcast on VHF using a 405 line picture.

 The Beatles appear for the first time on 'Ed Sullivan Show'

 Procter and Gamble, the largest American advertiser, refuses to advertise on any show that gives
 
 

"offense, either directly or by inference, to any organized minority group, lodge or other organizations, institutions, residents of any State or section of the country or a commercial organization."
1965 :

 The Vietnam War becomes the first war to be televised, coinciding with CBS's first colour transmissions and the first Asia-America satellite link. Protesters against the war adopt the television-age slogan, 'The whole world is watching'.

 Sony introduces the CV-2000, a small home videorecorder.

 Westinghouse develops the Phonovid process in an attempt to produce a commercial videodisc. While this microgroove disc provides a good quality picture it can only store 200 fixed images on each disc.

 The Japanese produce the first miniature television. The transistorized set is 10 inches (25 cm) high with a 7 1/2in color screen and only requires 10% as much power as an average TV.

 The MVR videodisc recorder is demonstrated in California. 600 frames of action lasting 20 seconds can be recorded on the magnetic disc and replayed immediately. Single frames can also be replayed or erased.

 1966 :

 Colour television signals are transmitted by Canadian stations for the first time.

 The BBC begins color TV broadcasts.

 The first video slow motion appears on NBC during the World Series of Baseball.

 ...also see item at 1981 regarding Clive Sinclair

 1967 :

 Sony introduces the first lightweight, portable and cheap video recorder, known as the 'portapak'. The portapak is almost as easy to operate as a tape-recorder and leads to an explosion in 'do-it-yourself' television, revolutionizing the medium.

 The FCC orders that cigarette ads on television, on radio and in print carry warnings about the health dangers of smoking.

 The first television broadcast to incorporate the use of an electronic character generator. Until this time, cameras have scanned images of art cards with typography, and the image has been superimposed on another image.

 RCA develops a battery operated, tubeless TV camera that can transmit its own pictures and weighs only 2.2 lb (1kg).

 CBS pioneers home video with the EVR (electronic video recorder). The tape cartridge is played on an automatic player with rewind, fast forward and freezeframe capabilities. The picture quality is comparable to that of 35 mm films shown on TV.

 Ray Dolby develops his noise reduction system

 1968 :

 Sony develops the Trinitron tube, revolutionizing the picture quality of colour television.

 Intelsat completes global communications satellite loop

 The US is estimated to have 78 million of the world's 200 million TV sets, the USSR 25 million, Japan 20.5 million, the UK 19 million, W. Germany 13.5 million and France 10 million.

 The U.S. television industry now has annual revenues of about $2 billion and derives heavy support from tobacco advertisers.

 Television brings war into the home for the first time as US TV news broadcasts show the Tet Offensive in South Vietnam. In the face of controversial pictures such as these, CBS newsman Walter Cronkite, along with many in his TV audience, begins to question the conduct of the war.

 1969 :

 On July 20, 1969, the first television transmission from the moon is viewed by 600 million viewers around the world.

 'Sesame Street' debuts on American Public Television, and begins to revolutionize adult attitudes about what children are capable of learning.

 1970 :

 Motion Picture box office revenue is $896 million. Television advertising revenue is $3 billion.

 In Japan, the Matsushita multiplex adaptor is used to receive transmission of television programs broadcast in two languages at once, giving the viewer the option of watching a foreign film in the original language or in Japanese.

 The excellent quality of the AEG Telefunken-Decca Teledec is demonstrated in W. Berlin. This videodisc is made of a sheet of PVC 0.04 in. ( 1mm ) thick. A 9 in. ( 22.5 cm ) disc plays for five minutes, a 12 in. (30 cm) runs for 12 minutes.

 1971 :

 Sony introduces the U-Matic three quarter inch video cassette recorder.

 SMPTE Time Code makes computer assisted videotape editing possible. The result is the CMX 300.

 AT&T transmits the first intercity broadcast of television with stereo sound.

 The BBC pioneers digital television, transmitting the audio signal as part of the video signal, rather than separately. This improves the quality of sound reception at the edges of the broadcast area and reduces the overall cost of broadcasting.

 Philips of the Netherlands develops a laser disc, its Video LP (VLP). It comes in two sizes: one can record an hour of TV on either side, the other records only 30 minutes on each side but has freeze-frame capability. The surface of the disc is smooth and reflective; a laser takes the place of the phonograph needle. Philips intends for the product to compete with the videocassette but does not market it for several years.

 Canada's 'Anik I', the first domestic geo-synchronous communications satellite, is launched, capable of relaying 12 television programmes simultaneously.

 India has a single television station in New Delhi, able to reach only 20 miles outside the city.

 South Africa has no television at all.

 1972 :

 The Munich Olympics are broadcast live, drawing an estimated 450 million viewers worldwide. When Israeli athletes are kidnapped by Palestinian terrorists during the games, coverage of the games cuts back and forth between shots of the terrorists and footage of Olympic events.

 The American-conceived Intelsat system is launched, becoming a network and controlling body for the world's communications satellite system.

 The BBC announces a new "electronic book" information service, CEEFAX. Subscribers have decoders plugged into their TV sets and, by punching the appropriate button on a keypad, receive current stock prices, news or weather. Other 'data pages' will be added to the service in time.

 1973 :

 Ninety-six countries now have regular television service.

 The first microwave pay TV system feeds hotels in Washington, DC.

 The UK's Independent Television channel (ITV) introduces ORACLE, a television information service in direct competition with the BBC's CEEFAX system. ORACLE offers weather, traffic, news, sports and financial information. In the following year BBC and ITV will agree to a standard so that subscribers can use the same decoder for either service.

 Ikegami introduces the first electronic news gathering - ENG - camera. It is a highly portable video camera, which can be easily managed on the shoulder of one man. This development leads to a revolution in the immediacy of TV news coverage. Some feel it is the start of a radical change in world politics with its effects seen in everything from Watergate to international terrorism.

 Watergate unfolds on the air in the U.S. and ends the following year with Nixon's resignation.

 U.S. producers sell nearly $200 million dollars worth of programmes overseas, more than the rest of the world combined.

 1974 :

 Panasonic, a division of Matsushita, demonstrates high definition television, with 1125 scanning lines, in New York.

 Colour television begins in Australia.

 The US experiments with captioned television for the hearing-impaired.

 97% of American homes have at least one TV set and it is on at least five hours per day.

 1975 :

 Sony introduces the Betamax VTR.

 A study indicates that the average American child during this decade will have spent 10,800 hours in school by the time he or she is 18, but will have seen an average 20,000 hours of television.

 Home Box Office is the first satellite television broadcasting network.

 Studies also estimate that, by the time he is 75, the average American male will have spent nine entire years of his life watching television; the average British male will have spent eight years watching.

 Both RCA and Thomson-CSF announce videodisc systems.

 The Thomson approach passes laser light through a transparent medium to a photodiode.

 The RCA approach relies upon capacitance transfer of information from the disc via a stylus.

 1976 :

 Ampex perfects the moving head principle for slow motion video recording.

 IBA of the UK demonstrates the first digital VTR images.

 JVC ( Japan Victor Co. ) introduces VHS, a half inch cassette system designed for home consumer video recording.

 First coast to coast stereo simulcast, in which a television program, 'Live From Lincoln Center' is broadcast nationwide from New York, and its stereo sound portion is broadcast at the same time on a nationwide network of radio stations.

 The Olympics, broadcast from Montreal, draw an estimated 1 billion viewers worldwide.

 British TV networks begin first teletext system.

 1977 :

 South Africans see television for the first time on May 10, as test transmissions begin from the state-backed South Africa Broadcast Co. The Pretoria government has yielded to public pressure after years of banning television as being morally corrupting. Half the broadcasts are in English; half in Afrikaans.

 Home color TV cameras are offered to the public.

 The new 1700 video cassette recorder from the Dutch company Philips plays at half the speed of previous home video systems, cutting the cost of tapes in half while doubling the playing time. For the first time, a complete feature film can be recorded on one cassette.

 1978 :

 Ninety-eight percent of American households have television sets, up from nine percent in 1950. Seventy-eight percent have colour televisions, up from 3.1 percent in 1964.

 A full screen digital image is recorded on video tape for the first time.

 SMPTE recommends standards for NTSC color registration through the use of color bars.

 Stereo television broadcasting begins in Japan.

 The British Post Office is experimenting with a viewdata or television information service it calls Prestel. A special module links any ordinary telephone and TV to the computerized data service.

 The Canadian Government introduces its own system for videotex. It is called Telidon, and boasts graphics as well as text. It produces superior graphics through an alphageometric based technology.

 Videotex is similar to teletext in that it is an electronic system for the display of information on the television screen of a set equipped with a decoding device. Unlike teletext, the system provides service from a central computer; information is relayed to the home user through cable or telephone lines. Moreover, it offers the opportunity of user interaction.

 The American videotex system is known as ANTIOPE. Compatible worldwide, it provides both broadcast and videotex technology, as well as hard copy printouts.

 1979 :

 There are now 300 million television sets in operation worldwide.

 BASF of W. Germany demonstrates the LVR ( longitudinal video recording ) system; it can fit three hours of video onto the smallest cassette in the world.

 Flat-screen pocket televisions, with liquid crystal display screens, are patented by the Japanese firm Matsushita. The pocket television is no bigger than a paperback book.

 Philips of the Netherlands markets LaserVision, a digital video disc sytem that uses a helium neon laser to read the disc, eliminating the interference caused by dust or scratching. The player itself is smaller than many cassette decks.

 JVC (Japan Victor Co.) introduces a new video disc system. This system uses a sapphire stylus and, unlike the Philips LaserVision set, it can play either audio or video discs on the same turntable.The stylus is good for 2000 hours of play.

 1980 :

 India launches its national television network.

 Sony demonstrates the first consumer Camcorder, a combined video camera and recorder in one small package.

 The British Post Office makes its Prestel Viewdata or public TV information service available to the public. One linking module gives an ordinary telephone and television access to the computerized data system. The system goes international the following year.

 Cable News Network ( CNN ) goes on the air in the U.S.

 Closed captioning, an added digital text signal for the deaf which can be decoded with special devices, is designed at ABC.

 1981 :

 The first professional camcorders are employed at ENG, thus making it possible for one man to completely cover a news event.

 First National of the US releases 'Kididisk', a new videodisc home teaching device with rewind, fast forward and freeze-frame capabilities

 After five years of work on the project, Sinclair Radionics of Cambridge, England introduces Microvision, the first pocket-sized TV. From almost anywhere in the world Microvision can receive black and white pictures on its 3 inch ( 7.5 cm ) screen. It also includes an FM radio receiver. It retails for £50 ( $100 ).
 
 

Feedback:

 ..."I would like to point out an error in the "2500 Years of Communications History." The British inventor Clive Sinclair, or his company, Sinclair Radionics, brought the first pocket TV in the world to the market in 1977, not in 1981. In fact, the prototype was presented to the public 11 years earlier, in 1966!

 A lot of information concerning the Sinclair Pocket TVs can be found at the following www-address:

 http://www.nvg.unit.no/spectrum/tv1a.htm

 I would also like to inform you that the Sinclair Microvision is acclaimed in encyclopaedias of design because of its remarkable design quality. It is most often dated 1976, but it did not actually come on the market before January 1977"

 A reader who wished to remain anonymous

1982 :

 Chyron debuts a character generator which may be controlled and programmed by a personal computer.

 The first flat screen portable TV is offered to the public.

 The Marconi Co. announces plans to begin commercial satellite TV in the UK before the end of 1986. The new service will have two channels. One will show feature films, the other will rerun highlights from old programs.

 National Panasonic markets the UK's first stereo video recorder, the NV-7900. The remote control gives the viewer easy accesss to 25 different functions of the recorder, which can be used with a stereo TV set, or a stereo audio system in conjunction with a mono TV set.

 1984 :

 8mm consumer video recorders are marketed in the US.

 Stereo TV broadcasting is authorized by the FCC.

 Kodak introduces its Kodavision home video system.

 Seiko, Sony and Casio simultaneously produce pocket televisions with flat screens. These are followed by wristwatch televisions.

 1985 :

 In the UK, teachers and schoolchildren collaborate on the Domesday Project, a sort of time capsule on video disc. It combines digital data with still and moving images to produce a record of Britain in the year 1985.

 At Expo '85 in Tsukuba, Sony demonstrates the Jumbotron, a high definition TV screen 40 meters wide and 25 meters high.

 Matsushita Electric Industrial Co. of Japan produces a 3D television which does not require the use of special glasses. The first model has a 14 inch screen.

 Sony introduces its Video 8 camera. It weighs less than 5 lbs.

 Sony builds a radio the size of a credit card.

 1986 :

 The crucial battle for a democratic revolution in the Philippines is focused on the control of Channel Four, the television station owned by the government. The live broadcast of Ferdinand Marcos' inaugural ceremony is cut off in mid-gesture by the rebels and replaced by a John Wayne movie.

 1987 :

 Pope John Paul is the subject of the largest satellite television broadcast in history, called 'Prayer For Peace' reaching over 1.5 billion people around the world. Twenty satellites and thirty transponders are used to transmit the program to 25 countries on five continents.

 Half of all homes in USA with TV are on cable.

 1988 :

 Sony introduces the Video Walkman, a portable TV and VCR with a 3 inch screen that weighs only 2-1/2 lbs. The list price in the US is $1300.

 At the same time the first pocket-size color TVs become available. Sony, Sharp Electronics ( Magnavox ) and NAP Consumer Electronics Corporation all introduce color models with flat liquid crystal display ( LCD ) screens. The picture screens on these models are 3 inches ( 7.6 cm ) wide and only 1/8 of an inch ( 3 mm ) thick. They sell for about $600.

 1989 :

 The manufacturers of video cassette systems offer a sharper picture in new higher resolution products. The JVC Company of America in Elmwood Park, New Jersey introduces the Super VHS format with a 440 line picture rather than the 220 line picture of conventional VHS. Sony markets its new ED-Beta system, with 500 lines to a picture, as opposed to the old Beta's 300.

 1990 :

 1446 television stations broadcasting in United States.

 1991 :

 During the Gulf War, CNN coverage of the conflict is so extensive and wide-ranging that it is commonly remarked only half in jest that Saddam Hussein is watching CNN for his military intelligence, instead of relying on his own information-gathering methods.

 3 out of 4 U.S. homes own VCRs; fastest selling domestic appliance in history.

 1993 :

 A 'TV Guide' poll finds that one in four Americans would not give up television, even for a million dollars.

 1996 :

 There are over a billion television sets in operation around the world.


What is the goal of
"A Chronology of Communication Related Events"


For a good many years I have taught courses and given lectures on many aspects of communication 
systems and technology.  In a number of instances the audience for these presentations had little or no background in physics or engineering and, as a result, I often found it difficult to elucidate some of the fundamental and enduring concepts in communication.

In this context, I have found it useful (or, at least, personally rewarding) to take a semi historical approach.  For example, understanding electromagnetism and its implications in electromagnetic communication is a very profound conceptual leap for those not well schooled in physics.  However, tracing through how the understanding of these ideas has evolved over time can help to pinpoint the thorniest conceptual hurdles.  In this way then I have found that the development of this chronology as valuable teaching adjunct.

Obviously, I am not an historian and the history presented here is very schematic, highly selective and not very authoritative.  There are very big gaps.  In particular, I have not touch upon the development of spoken and written language.  But, in spite of obvious limitations I believe that this evolving chronology does give a flavor of how humankind has come to understand communication and communication technology.

Much of the material presented in this chronology is taken from other web pages and, where appropriate, I have tried to given due recognition to these sources. 
 

Sources or References:

Russell Naughton's work is a primary inspiration and source for these web pages:
Technology and Society
2500 Years of Communications History: Part 1
2500 Years of Communications History: Part


Surfing the Aether

Genesis I, verse 3.

Genesis I, verses 1-5

Be advised that the information here is taken from many sources, and sifting through various sources and viewpoints makes for lively debate. That is to say, you may encounter inconsistencies concerning time and event - or even who was 'first' to do something or other.  I have done my best to verify dates and events, but there are certainly errors.
in some cases...texts are not internally consistent.

Other Related Chronologies

Electrical Timeline
Electricity and Magnetism Time-Line
The  FTHE Web History of Telecommunications
History 291 Home Page
IEEE History Center Milestones List
The Master-List of Dead Media
Miscellanea
Physics Time-Line  
The Scientific Revolution: Useful Dates
 
 



This page was prepared and is maintained by R. Victor Jones
Comments to: jones@deas.harvard.edu.
Last updated August 20, 1999