| 1640 | The first vacuum. Otto von Guericke's air pump | 
| 1643 | The barometer first demonstrated by Evangelista Torricelli | 
| 1654 | Magdeberg Hemispheres a demonstration of the force of air pressure | 
| 1672 | Improved air pump and treatise on vacuum experiments published. | 
| 1716 | Jacob Hermann suggests that gas pressure is proportional to density and to the square of the average velocity of the gas particles in motion | 
| 1811 | A principle stated in 1811 by the Italian chemist Amedeo Avogadro (1776-1856) that equal volumes of gases at the same temperature and pressure contain the same number of molecules regardless of their chemical nature and physical properties | 
| 1855 | Johann Geissler produces a mercury vacuum pump and with it he produces the first good vacuum discharge tubes | 
| 1856 | Karl Kronig suggests that gas molecules in equilibrium travel in straight lines unless they collide with something | 
| 1858 | Julius Plucker demonstrated that magnetic fields bend what later became known as cathode rays. | 
| 1860 | Joseph Swann patents the the carbon filament incandescent lamp that operates in a partial vacuum | 
| 1862 | Geissler-Topler mercury vacuum pump developed | 
| 1865 | Hermann Sprengel develops the mercury drop pump | 
| 1870 | Sir William Crookes vacuum pumping system | 
| 1871 | C F Varley suggests that cathode rays are particles | 
| 1871 | Sir William Crookes advances the idea that cathode rays are negatively charged particles | 
| 1874 | G R Carey invents the photo-electric cell | 
| 1876 | Sir William Crookes demonstrates pumping by chemical getters | 
| 1876 | L von Babo develops a self-recycling Sprengel vacuum pump | 
| 1876 | Alexander Graham Bell invents and demonstrates the telephone | 
| 1879 | Thomas A Edison files US patent on high vacuum carbon filament incandescent lamp | 
| 1879 | Sir William Crookes develops the Crookes Tube, an early form of cathode ray tube | 
| 1879 | Edison improves the self-recycling Sprengel-Geissler mercury vacuum pump | 
| 1880 | Apparatus for evacuating Edison's electric lamps. Based on Crookes design | 
| 1883 | Thomas A Edison first observes thermionic emission in a vacuum | 
| 1883 | John Ambrose Fleming presents a paper on the 'molecular shadow' to the Physical Society of London on May 26 | 
| 1883 | In October 1883 the amalgamation of Edison Electric Light Co Ltd and Swan Electric Lighting Co to form Edison and Swan United Electric Light Co. Ltd. | 
| 1887 | Sir William Crookes performs the Maltese Cross experiment | 
| 1889 | Jonathan Zenneck improves Braun's CRT and adds time base deflection | 
| 1889 | The British General Electric Co. Ltd was formed | 
| 1885 | Sir William Preece duplicates Edison's experiment, makes quantitative measurements and presents a paper to The Royal Society | 
| 1886 | Eugen Goldstein observes 'canal' rays (German = kanalstrhlen}. So called because they were emitted through a hole in the cathode. | 
| 1890 | A C Cossor Ltd was formed. | 
| 1891 | George J Stoney suggests the name of electron for cathode ray particles | 
| 1896 | Mallgnani Corp demonstrates the use of phosphorus gettering | 
| 1896 | The British Thomson-Houston Co. Ltd. was formed | 
| 1897 | Sir Joseph Thomson discovers 'corpuscles' later called electrons | 
| 1897 | Guglielmo Marconi sets-up in July 1897 the Wireless Telegraph and Signal Company Limited to commercially exploit his patents | 
| 1899 | The British Westinghouse Electrical and Manufacturing Co. Ltd was formed. This later became the Metropolitan-Vickers Co. Ltd, (Metrovick) | 
| 1900 | James Dewar builds a cryosorption pump using activated charcoal and liquid air | 
| 1900 | John Ambrose Fleming becomes scientific adviser to Marconi's company | 
| 1901 | W C Roentgen wins Nobel prize for Physics for discovery of x-rays | 
| 1901 | Gugliemo Marconi transmits signal from England to North America | 
| 1901 | Richardson produces an equation for the emission of electrons from incandescent metal filaments | 
| 1901 | Peter Cooper Hewitt develops the fluorescent lamp | 
| 1902 | Georges Claude builds the first neon lamp | 
| 1902 | E Weintraub develops the mercury arc lamp and rectifier | 
| 1902 | Charles Proteus Steinmetz files a patent on mercury vapour lamp with halide salts to improve colour | 
| 1902 | Peter Cooper Hewitt develops the mercury vapour lamp | 
| 1902 | A C Cossor Ltd make the first British examples of Braun's CRT | 
| 1903 | Harris J Ryan builds magnetic deflection CRT's | 
| 1904 | Arthur Wehnelt publishes details of the oxide coated hot cathode CRT | 
| 1904 | January 1904, Arthur Wehnelt patents a diode. The patent does not mention use for rectification of RF. The device is described in connection with charging accumulators | 
| 1904 | October 1904, Sir Alexander Fleming produces rectification of RF in a valve. Valve history begins | 
| 1904 | November 16 1904, Sir Alexander Fleming applies for a patent on the Oscillation Valve, later known as the Thermionic Valve and Fleming Diode. | 
| 1905 | Philip Eduard Anton von Lenard wins Physics Nobel prize for Cathode Rays | 
| 1905 | Wolfgang Gaede makes rotary mercury-sealed mechanical vacuum pump | 
| 1905 | Albert Einstein explains the photoelectric effect | 
| 1906 | W Voege and Rohn build the thermocouple vacuum gauge | 
| 1906 | Lee de Forest invents the Audion (triode) as a sensitive detector | 
| 1906 | Dieckmann, Glage, Rosing, Campbell-Swinton propose the use of the Braun tube to display television images | 
| 1908 | Fleming replaces the carbon filament in his valve with a tungsten filament. This is before a process of making ductile tungsten had been devised | 
| 1909 | Otto von Baeyer develops the ionisation vacuum gauge | 
| 1909 | Robert Milikan measures the charge on the electron by the oil drop experiment | 
| 1909 | Guglielmo Marconi and Carl F Braun win Physics Nobel prize for wireless telegraphy | 
| 1910 | Pfeiffer Co produce the rotary oil-sealed mechanical vacuum pump | 
| 1910 | Georges Claude demonstrates the neon lamp in public | 
| 1910 | German telephone relay soft valve by Leiben-Reiz | 
| 1910 | The early production Audion's looked like this | 
| 1911 | Edwin H Armstrong invents the regenerative circuit | 
| 1911 | 'Doc' Herrold begins first radio broadcast service in San Jose California | 
| 1911 | Henry Round of the Marconi company commences work on the design of a diode valve | 
| 1912 | Wolfgang Gaede develops first theory and experiment on the molecular-drag vacuum pump | 
| 1912 | Irving Langmuir produces gas filled incandescent lamp | 
| 1912 | Lee de Forest makes the first valve amplifier | 
| 1912 | H M Fassenden develops the Heterodyne receiver | 
| 1913 | Wolfgang Gaede first diffusion pump using mercury | 
| 1913 | A Dufour develops a high voltage, continuously pumped CRT and records directly onto photographic plates | 
| 1913 | John Johnson and H J Van der Bijl develop the first commercial CRT. Western Electric 224-A | 
| 1913 | Marconi receiver with Captain Round's C valve | 
| 1913 | Captain Round's T transmitting valve developed | 
| 1913 | Saul Dushman produces a 40 kV vacuum rectifier | 
| 1913 | W D Coolidge produces a High Voltage X-ray tube | 
| 1914 | ATT purchase licence from de Forest in August 1914 | 
| 1914 | Marconi files suit against Lee de Forest over triode | 
| 1914 | AEG-Telefunken develops standardised valves for radio reception. EVN94 and EVN129 | 
| 1915 | Edison and Swan Co. produce Round valves for the Marconi Co. | 
| 1915 | GE in America begin production of Pliotrons (triodes) | 
| 1915 | In France the first hard vacuum triode was made. During the war over 100,000 were made by the companies Metal and Fotos | 
| 1915 | Western Electric patents the indirectly heated cathode | 
| 1915 | October 1915 Cunningham develops the tubular Audion | 
| 1916 | Lee de Forest builds tubular Audions. See DV5 | 
| 1916 | The White soft valve produced. This has been developed by a British team working at the Cavendish Laboratory under the direction of J J Thomson | 
| 1916 | Siemens and Halske in Germany develop the Type 'A' vacuum tube. About 50,000 are subsequently made | 
| 1916 | A British version of the French valve was introduced. This was the R Type | 
| 1916 | The British Thomson Huston Co. commence making R Type valves for military use | 
| 1916 | GEC (Osram) commence making R Type valves for military use | 
| 1916 | Irving Langmuir develops a high-speed diffusion pump and all-metal condensation pump | 
| 1916 | The Edison and Swan United Electric Light Co. Ltd. changes name to Edison Swan Electric Co. Ltd. | 
| 1914 | ATT purchase de Forest's patent for the triode | 
| 1917 | The Metropolitan-Vickers Co commences production of the R Type | 
| 1917 | July 3rd 1917, F Lowenstein's patent for negative bias | 
| 1919 | October 1919. Marconi and GEC set up a joint company to manufacture valves. This was the Marconi-Osram Valve Co. Ltd. Later known as M-OV | 
| 1920 | In September Capt. S R Mullard forms the Mullard Radio Valve Co. Ltd. | 
| 1920 | Edwin Howard Armstrong invents the superhet receiver | 
| 1920 | Irving Langmuir develops the thoriated tungsten filament | 
| 1920 | Wolfgang Gaede develops the box pump | 
| 1921 | Albert Einstein is awarded the physics Nobel prize for the photoelectric effect | 
| 1922 | Mullard introduce the ORA general purpose valve | 
| 1922 | Cossor introduce the P1 its first valve design post WW1. The electrode shapes avoided patents held by others | 
| 1922 | On the 14th Novenber 1922 the BBC went on the air from 2LO in London | 
| 1923 | Robert A Milikan is awarded the physics Nobel prize for measuring the charge on the electron | 
| 1923 | Lee de Forest introduces DV/DL tubular Audions. See DV5 | 
| 1923 | M-OV introduce Captain Round's DEQ high impedance detector | 
| 1924 | L T Jones and H G Tasker demonstrate electrostatic focusing of a CRT with magnetic deflection | 
| 1924 | Lisa Meitner of Germany discovers the radiationless electron transition known as the Auger effect. Named after Pierre Auger of France who discovered the effect in 1926. See Augetron | 
| 1925 | Bakelite based valves with the evacuation 'pip' concealed within were introduced | 
| 1926 | Mullard introduce the first series of their PM valves. See The Azide Process | 
| 1926 | Loewe vacuum 'integrated circuit' multi valves introduced | 
| 1926 | Farnsworth image dissector produced | 
| 1926 | M Siegbahn introduces the disk type of molecular drag pump | 
| 1927 | Philo T Farnsworth demonstrates an all-electronic television system in San Francisco | 
| 1927 | Kenjiro Takayanagi demonstrates a gas focused oscillograph CRT to display television images | 
| 1927 | In the UK the S625 the world's first screened grid valve is produced | 
| 1927 | May 1927, the landmark UX280 rectifier was introduced. This was subsequently manufactured for over 50 years | 
| 1927 | Harold S Black discovers the benefits of negative feedback | 
| 1927 | Albert W Hull builds the first Thyratron | 
| 1927 | Friedrich Meyer, Hans J Spanner and Edmund Germer, in Germany, patent the high-pressure metal vapour UV and fluorescent lamp | 
| 1928 | The B5 base was introduced | 
| 1928 | The Mullard company introduce the first Pentode to the UK market | 
| 1929 | Kenneth C D Hickman develops low vapour pressure synthetic oils | 
| 1929 | Cecil R Burch produces a gas diffusion pump employing low vapour pressure oils | 
| 1929 | Complete amateur radio station with one valve transmitter and one valve receiver | 
| 1929 | Manfred von Ardenne demonstrates an all-electronic television in Berlin | 
| 1929 | Farnsworth electron multiplier developed | 
| 1929 | Vladimir K Zworykin files a patent on the kinescope. Zworykin later developed the Iconoscope camera tube | 
| 1930 | The Mazda AC/Pen, introduced in 1930, was the first technically successful indirectly-heated power pentode capable of enough output to drive a moving-coil loudspeaker at good volume | 
| 1931 | The external metalising of valves was introduced. Generally the metal was painted for protection. Red, Gold or Grey. | 
| 1931 | National Union in the USA produce the first valves for car radios | 
| 1932 | Alan B Du Mont starts to apply CRT's to television | 
| 1933 | The B7 base was introduced | 
| 1933 | Westinghouse introduce a mercury-arc rectifier, the Ignitron | 
| 1933 | E H Armstrong announces frequency modulation | 
| 1934 | The B9 base was introduced | 
| 1934 | In the USA the 6.3 Volt filament is adopted as standard for both AC and DC filaments and heaters | 
| 1934 | The GE 6E5 'Magic Eye' tuning indicator is introduced. RCA produce 6E5 in 1935 | 
| 1934 | The introduction of miniature Acorn valves for VHF. See 955 | 
| 1934 | In the UK M-OV introduced the Catkin range of valves with external anodes | 
| 1935 | Wolfgang Gaede produces the gas ballast pump | 
| 1935 | Kenneth C D Hickman produces a fractionating oil diffusion pump and associated oils | 
| 1935 | RCA introduce the IO base with the launch of the metal tube valve 6L7 | 
| 1935 | RCA nine original valves appear in the RCA metal valve family | 
| 1935 | Watson Watt demonstrates that aircraft reflect radio waves | 
| 1935 | John Logie Baird demonstrates a 700 line high resolution television system | 
| 1935 | Oskar Heil patents the field effect transistor. The device, however, did not work | 
| 1936 | The world's first regular television broadcast by the BBC employing the EMI electronic system | 
| 1936 | Mahn and Mecalf present a paper on velocity modulated valves. The key principle within the klystron | 
| 1937 | At Stanford University the Varian brothers produce the first working Klystron | 
| 1937 | C M Van Alta produces a diffusion pump with a pumping rate in excess of 100 litres per second | 
| 1937 | L Malter demonstrates a multi-stage, self fractionating diffusion pump | 
| 1938 | Mazda introduce the MO in the UK as an alternative to the International Octal | 
| 1939 | RCA and Du Mont demonstrate Television at the NY World's Fair | 
| 1939 | The Loctal or B8B was introduced in America | 
| 1939 | The Philips introduce the all glass valve and with it the B9G base | 
| 1939 | The first all-glass valve for use above 30 MHz was produced. The EF50 played a major part in early Radar | 
| 1939 | The B7G all-glass valve base was introduced in America. Its introduction to the UK was in 1947 | 
| 1940 | February 21st 1940 John Randall and Harry Boot make operational the cavity magnetron at Birmingham University | 
| 1940 | On September 6th 1940 Sir Henry Tizard takes the cavity magnetron to the USA. This is one of the most secret inventions of the war | 
| 1940 | In September 1940 the first RDF system using a cavity magnetron is made in the UK | 
| 1940 | In the USA the first all glass B7G 1.4 Volt miniature valve is introduced. This was the 1R5 | 
| 1941 | In America the 525 line system is approved by the FCC for commercial black and white broadcasting | 
| 1941 | A UHF oscillator is made using Acorn valves. See 955 | 
| 1941 | The UK government introduce the common valve (CV) lists to streamline procurement and increase flexibility in sourcing the valves required by all branches of government especially the military | 
| 1942 | Rudi Kompfner at Oxford University produces the first travelling wave tube | 
| 1943 | Dr Tommy Flowers builds the first electronic computer for code breaking at Bletchley Park | 
| 1943 | Percy Spencer of the Raytheon Co designs the laminated anode cavity magnetron which increased production rates | 
| 1945 | Double triodes | 
| 1947 | Bardeen, Brattain and Shockley demonstrate the first semiconductor amplifier | 
| 1947 | B7G used on UK valves for the first time | 
| 1948 | F C Williams describes the use of a CRT as a digital memory | 
| 1948 | The B8A 'Rimlock' valve base is introduced | 
| 1948 | B9A based all glass double triodes 12AU7, 12AX7 and 12AT7 are introduced | 
| 1949 | Valve memory is introduced | 
| 1950 | October 3rd 1950 the transistor is patented | 
| 1950 | RCA demonstrate the shadow mask colour TV tube | 
| 1952 | Ring getter with U-shaped cross section for valve manufacture is introduced | 
| 1953 | B8A 'Rimlock' valves of all glass construction are introduced in the UK | 
| 1954 | Mullard introduce the EL34 25 Watt dissipation audio output pentode | 
| 1954 | Texas Instruments produces the first silicon transistor | 
| 1957 | The Nixie display tubes are introduced | 
| 1958 | Elmer Fridrich and Emmett Wily file a patent application on the tungsten halogen lamp | 
| 1958 | Varian Associates introduce the 'modern' Vacsorb cryosorption pump | 
| 1958 | The IMB 709 was introduced. This was the last major valve computer and featured magnetic core memory | 
| 1959 | IBM 7090 introduced, this is the world's first all transistor computer | 
| 1959 | The Varian Klystron VA842 introduced. This multi-cavity liquid-cooled Radar klystron is the largest documented production klystron | 
| 1960 | Varian Associates Inc. produce the 1000 Litre per second Valcon pump | 
| 1960 | Ross Aiken develops CRT for aircraft and 14 inch thin CRT | 
| 1960 | The Nuvistor is developed. See 6CW4 | 
| 1960 | Ali Javan invents the Helium-Neon gas discharge laser | 
| 1961 | C H Kruger and A H Shapiro unveil statistical theory of turbo-molecular pumping | 
| 1961 | Varian Associates Inc produce very large sorption pumps for roughing large chambers | 
| 1961 | Gilbert Reiling files a US patent for 'modern' metal-halogen incandescent lamp | 
| 1961 | William R Wheeler introduces the UHF metal-gasket captured step-seal | 
| 1962 | Fairchild Semiconductors produce the first integrated circuit | 
| 1962 | Varian VA126 high power travelling wave tube introduced | 
| 1968 | July 1968, Robert Noyce and Gordon Moore founded Intel | 
| 1968 | A Y Cho et al develop molecular-beam epitaxy | 
| 1969 | K H Mirgel produces the vertical uni-directional turbomolecular pump | 
| 1971 | Intel introduce the 4004, the world's first microprocessor. This was a 4-bit device in a 16 pin DIL package. | 
| 1974 | First oil-free vacuum pump | 
| 1975 | Altair computer with microprocessor introduced for home use | 
| 1975 | NASA Cryo-pumps for space simulation and semiconductor manufacture | 
| 1976 | April 1976, Steve Jobs and Steve Wozniak found Apple computer | 
| 1977 | Mass production of valves ends in most Western European countries and the USA | 
| 1978 | June 1978, the industry standard 8086 16-bit microprocessor is made. It has 29,000 transistors and a clock speed of 4.77 MHz. It was made in quantity on 4-inch silicon wafers | 
| 1986 | Raytheon close the last major valve production line in the USA | 
| 1989 | The 1.2 million transistor Intel 80486 is produced. The initial clock frequency is 25 MHz | 
| 1993 | Intel introduce the Pentium processor. This is fabricated on 8-inch wafers. The 8-inch wafer process having been developed in April 1992 |