A Chronology of Communication Related Events
(A Work in Progress)
According to Genesis with dating by Archbishop Ussher (Source)-2900:"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.
Hieroglyphics, characters with a recognizably graphic character, are in use.
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 named the play Agamemnon: (Source)
Location Modern Name Modern NameAltitude (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
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.,when rubbed with a piece of silk or fur amber develops the ability to attract little objects such as feathers. (Source-1, Source-2 andSource-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).-460:
The "Marathon Run." (Source)-427:
Thucydides records the use of beacon fires to warn a fleet of 53 Spartan vessels that 60 Athenian triremes were heading towards them and preparing to attack.-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." (Picture-1 and Picture-2; Source-1 and Source-2).Aristotle describes image projection in terms of the camera obscura. His concept involves 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.-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 visionBC..."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."
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.1481:1550 :
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,Source-2, and Source-3)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 and Source-2)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-1 and Source-2) The Dutch spectacle maker Hans Lippershey (1570-1619) is usually credited with making telescopes widely known. (Source)1649:
Athansius Kircher, a German Jesuit, constructs his "projector" and publishes Ars Magna Lucis et Umbrae. (Source)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. (Source)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-1 and Source-2)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, Source-2 and Source-3)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.1704:
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-1 and Source-2)
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. (Picture)
Hauksbee describes his extensive experiments in his book Physico-Mechanical Experiments on Various Subjects published 1709. (Source)
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, Source-2, Source-3 and Source-4) (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, Source-2 and Source-3)1748: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-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)
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, Source-2 and Source-3)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 attraction1786:
Gilles-Louis Chrétien develops the 'Physionotrace' for profile portraits1788:
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-1 and Source-2; Picture)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-1,Source-21794:
Robert Barker opens the first 'Panorama', a prototype of future movie housesVolta finds elecricity is generated by different metals1798:
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 images1807:
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
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..."1817:
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.
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 of1820:
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.
Davy shows that electric current forms a magnetic sheath around the wireAmpere formulates the right-hand rule1821:
John Herschel discovers the photographic fixative, hyposulfite of soda.
James Bowman Lindsay conduced experiments in communication utilizing the conductive properties of water.
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 thermoelectricity1823:
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.1825:
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'
André-Marie Ampère establishes mathematical basis for electrodynamicsAn 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 metal1827:
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 photographyBelgian 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 himMichael 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.1832: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.
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.1834:
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.
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.1835: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.
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.1838:
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
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.1839:
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.
Antoine César Becquerel examines electrochemical effect of light.The Daguerreotype is publicly announced at the Academy of Sciences in Paris and given to the world1840:
Hippolyte Bayard produces direct-positive images on sensitized paper
Alexander Walcott issued first American patent in photography for his cameraThe 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 process1842:
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.1843:
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.
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 House1846:
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-EvrardFizeau measures the velocity of electricity1851:
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.
Frederick Scott Archer publishes wet-collodion processWilliam Henry Fox Talbot makes first instantaneous photographs using electric spark illumination1852:
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.
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-engraphing1853:
In 1852, there are 6500 km of telegraph wire strung in England. By 1862, the number is up to 24,000 km.
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 WarFrench engineer Charles Bourseul, an expert in telegraphy, experiments with ideas for a kind of telephone.1855:
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! (Source)
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'1858:
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.
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.1859:
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.
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.1861:
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.
James Clerk Maxwell's On the Theory of the Three Primary ColoursOliver 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.1862:
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.
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 miles1865:
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
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 communication1866:
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.1867:
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.
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 dynamo1868:
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 methodBasing 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.1871:
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.
Richard Leach Maddox invents the 'gelatin dry plate silver bromide' process1872:
John W. Hyatt begins manufacturing 'celluloid'Eadweard Muybridge started his photographic compilation of animals in motion1873 :
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.
Maxwell publishes a text on electricity, magnetism and theory of radio wavesTwo 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.1874:
May uses selenium to send a signal through the Atlantic cableHermann Wilhelm Vogel increases the spectral sensitivity of photographic emulsions by adding dyesFirst 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.
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. (Source)The Logograph, built by W.H. Barlow, creates a graphic representation of the sound vibrations produced by speech.1875 :
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.
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.1877:
The first Teletypewriter is used on Telegraph lines.
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 magnet1878:
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.
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.1879 :
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
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' system1880:
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.
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.1881:
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.
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
Subject: Clement Ader's phone.
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
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.1883:
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.
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.1884 :
Fitzgerald predicts the existence of electromagnetic waves
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.1885:
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.
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.1887:
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.
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.1888:
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.
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.1889:
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.
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.1890:
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.
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.1891:
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.
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.1892:
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.
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'1894:
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.
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 telegraphy1895:
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:
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)
In 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. Thus, in the middle of February, he 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, then Engineer-in-Chief for the Post Office, who immediately saw the importance of Marconi's apparatus. Under the guidance of his cousin Henry Jameson Davis, on June 2nd he filed the world's first patent application for a system of telegraphy using Hertzian waves -- British Patent number 12039. In July he demonstrated his apparatus to both the Post Office and the War Office, and a historic demonstration took place at Three Mile Hill on Salisbury Plain on the September 2nd, with officials from the GPO, the Navy and the Army present. Many more experiments followed in 1897. Marconi returned to Salisbury Plain and achieved a range of 7 miles (11.2km). On June 2 of that year, Marconi filed a preliminary patent application for his wireless telegraphy system. Because of the need to protect his patent interests, the specific details of Marconi's equipment were not disclosed publicly until June 4, when William Preece (1834-1913), Engineer-in-Chief for the Post Office gave a public lecture at The Royal Institution in London. (The relatives of Marconi's mother had provided him with an introduction to Preece.) The lecture was published in the next issue of The Electrician . Guglielmo Marconi takes his system of wireless telegraphy to England. Enlisting 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)
Marconi worked on his system for the next two years when he then felt it was ready to be
demonstrated publicly. The Italian government showed no interest so his mother took her son and
his two trunks of equipment toPreece immediately saw the importance of Marconi's apparatus and in June 1896 Marconi took out a
patent on his system of wireless telegraphy. 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)1896: Based on small scale trials at Bologna, Guglielmo Marconi on June 2, 1896 applied for a patent in England and demonstrated his system to postal-telegraph authorities in sequence of trials of in London and over Salisbury Plain. 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.
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:
Marconi transmitted signals from shore to a ship at sea 18 miles away.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 Company1898:
In March Popov equips a land station at Kronstadt and on the Russian navy cruiser Africa with his wireless communications apparatus for ship-to-shore communications.
Karl Ferdinand Braun constructs the first cathode ray to incorporate a scanning capability.
Marconi was granted a patent on July 2, 1897 (the complete patent specification had been filed on March 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.
The Marconi Company negotiates arrangements for a maritime intelligence network with Lloyds, the marine underwriters's association in May.In July Marconi radio reports the Kingston Yacht Regatta for Dublin's Daily Express.
Marconi comes to the US in September, 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 installs the worlds first commercial radio service on Rathlin Island off the coast of Ireland.
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.1899:
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.
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.