| 132 |
Seismograph built: inverted pendulum. (Chang Heng, China) |
15 |
| 725 |
Escapement mechanism devised to regulate oscillation of clock hands; anchor escapement 1759. (I Hing, China) |
12 |
| 1000 - 1062 |
Geared astrolabe designed with calendrical gearing: earliest record of complicated gear relating to clock. (al Biruni) |
12 |
1088 ca.
|
Su Sung escapement uses trip lever and scoop wheel: used in clock towers. (Su Sung, China) |
12 |
| 1195 ca. |
Arab treatise by Fakhr ad-din Ridwan b. Muhammad on great automaton water clocks. (Ridwan) |
12 |
| 1221 - 1222 |
Astrolabe: oldest geared machine (in complete state) in existence; signed and dated. (Muhamad b. Abi Bakr, Isfahan, Persia) |
12 |
| 1250 ca. |
Primitive rope escapement for clock illustrated in ALBUM. (V de Honnecourt) |
12 |
| 1256 - 1277 |
'Five Books of Clocks' in LIBROS DEL SABER DE ASTRONOMIA: on water clocks. (Alphonso the Wise, of Castile) |
12 |
| 1305 |
English statute acre and the English yard (called 'iron ulna') defined. (Edward I, Britain) |
10 |
| 1315 - 1319 |
Mechanical clock developed: perfected 1370. (western Europe) |
12 |
| 1335 |
Earliest clock identifiable as mechanical clock built. (John Dondi, Milan) |
12 |
| 1364 |
Verge escapement and foliot balance of early mechanical clocks partially illustrated in manuscript treatise. (JohnDondi) |
12
|
| 1364 - 1370 |
Mechanical clock built for Palais de Justice: reconstructed in early 1700s. (Henri de Vick) |
12 |
| 1370 |
Salisbury clock with crank mechanism. (Britain) |
12 |
| 1420 - 1429 |
First rain gauge: to measure precipitation with precision, for agricultural purposes. (Yi Ch'on, Korea) |
15 |
1450
|
Instrument making at Nuremberg: observatory, machine shop, and printing plant built. (Johann Muller (Regiomontanus), Germany) |
11 |
| 1475 ca. |
Spring drive introduced into mechanical clock. (Europe) |
12 |
| 1496 |
Brass bar of octagonal section made: yard defined as standard in Britain. (Henry VII, Britain) |
10 |
| 1509 - 1520 |
Original Nuremberg watches: spring driven clocks with single hands by German watchmaker. (Peter Henlein, Nuremberg, Germany) |
12
|
| 1561 |
Baldewin's astronomical clock. (Baldewin) |
12 |
1590 ca.
|
Load supported by cantilevered beam calculated as step toward studying strength of materials. (Galileo Galilei, Italy) |
17 |
| 1590 ca. |
Updated analysis of simple machines and treatise on statics (Guidobaldo also called Guido Ubaldi). (Guidobaldo, Italy) |
17 |
1597 ca.
|
Open, air-expansion thermoscope developed: forerunner of thermometer, for comparing temperatures. (Galileo Galilei, Italy) |
15
|
1608
|
First practical refracting telescope invented: sold as 'kijker,' later produced in binoculars. (Hans Lippershey, Germany, Netherlands) |
19 |
1610 ca.
|
Temperature regulator developed: later called thermostat, for scientific laboratory experiments. (Cornelis Drebbel, Dutch) |
15 |
| 1622 |
Circular form of slide rule invented. (Wm Oughtred) |
13 |
| 1630 - 1631 |
Auxiliary, or vernier, scale invented. (Pierre Vernier, France) |
13 |
| 1639 |
Castelli's rain gauge. (Castelli) |
14 |
| 1640 |
Screw caliper devised, used with telescope: later improved by Maudslay as micrometer. (Wm Gascoigne, Britain) |
13 |
1643 - 1645
|
Aristotle's nature-abhors-vacuum statement tested in experiments: mercury barometer invented. (E Torricelli, Italy) |
14 |
| 1650 ca. |
Stick-type slide rule developed. |
13 |
| 1655 |
High-resolution telescope invented: followed lens grinding process development. (Christiaan Huygens, The Hague, Netherlands) |
19 |
| 1657 - 1658 |
Pendulum-regulated clock built: 1675 balance wheel and spring oscillator, reliable accuracy, and precision gearing. (Christiaan Huygens, Netherlands) |
12 |
| 1660 ca. |
Modern thermometer developed by the Florentine Accademia del Cimento. (Italy) |
15 |
| 1661 |
Marine clock built: driven by coiled spring, with verge escapement. (Christiaan Huygens, Netherlands) |
12 |
| 1666 |
Screw-type micrometer described. (Adrien Auzout, France) |
13 |
1667 ca.
|
Hooke probably invented wind pressure gauge and improved bathometer, hygrometer, hydrometer, and barometer. (Robert Hooke, Royal Academy of London) |
11 |
| 1670 ca. |
Effective balance spring for marine clock devised: Hautefeuille and Huygens also claim. (Robert Hooke, Britain) |
12 |
| 1670 ca. |
Highly efficient microscope developed: uses single lenses of high quality and short focal length. (van Leeuwenhock, Delft, Netherlands) |
19 |
| 1675 |
First spring-operated watch built: under Huygens' supervision. (Isaac Thuret, Netherlands) |
12 |
1675 ca.
|
Anchor escapement introduced: replaces verge and foliot (Clement disputes Hooke claim). (Robert Hooke, Europe) |
12 |
| 1676 |
Repeating clock invented. (Barlow) |
12 |
| 1676 |
Hooke's law of elasticity: material behavior with stress. (Britain) |
17 |
| 1688 |
First reflecting telescope built: uses mirrors instead of lenses. (Sir Isaac Newton, Britain) |
19 |
|
18th Century |
|
| 1715 |
Deadbeat escapement for mechanical clock developed: means refinement of anchor escapement and more precision. (GeorgeGraham, London) |
12 |
| 1716 |
Highly accurate chronometer fit with roller bearing. (Henry Sully, Paris) |
12 |
| 1726 |
Gridiron-clock pendulum uses bimetallic strips for temperature compensation. (Harrison) |
12 |
| 1730 - 1732 |
Pitot tube invented to measure the velocity of water: used in studying ships, demonstrates surface speed. (Henri Pitot, Aramon, France) |
18 |
| 1754 - 1763 |
Chronometer developed and tested: conceived 1754, completed compensation balance 1756. (Pierre Le Roy) |
12 |
1758
|
Achromatic lens, combining convex and concave lenses, invented. (John Dolland, Britain) |
19 |
| 1762 |
His best chronometer produced: studies started in 1735 (invented 1759--F9 L7, invented gridiron pendulum 1726--W7). (John Harrison, Britain) |
12 |
| 1772 |
Watt's screw micrometer developed. (James Watt, Britain) |
13 |
| 1780 |
Dividing engine divides circle with accuracy: opens new era of precision instruments. (Jesse Ramsden, Britain) |
13 |
| 1783 |
Thermostat patented based on Drebbel's regulator for efficient incubator control. |
15 |
| 1790 - 1793 |
Metre defined by French Academy of Sciences (law adopted 1795). (France) |
10 |
|
19th Century |
|
| 1815 - 1817 |
Gas meter invented: prototype of devices measures gas consumption. (Samuel Clegg, Britain) |
14 |
| 1821 - 1833 |
Prony friction brake (dynamometer) invented: Baron Riche de Prony first tested it on Fourneron turbine in 1832. (Piobert and Hardy, France) |
17 |
| 1824 |
Act of Parliament of 1824 (revised 1855) legalizes yard standard based on pendulum swings. (Britain) |
10 |
| 1824 |
Tensile testing machine built. (Gabriel Lame, France) |
17 |
| 1826 |
LECONS SUR L'APPLICATION DE LA MECHANIQUE published: elastic limit established on strength of materials. (Claude L M Navier, France) |
17 |
| 1829 |
Poisson ratio established; elastic theory developed. (S D Poisson, France) |
17 |
| 1830 - 1832 |
Study of England's standardization leads to yard being fixed at 36-inch length. (Ferdinand Hassler, Britain) |
10 |
| 1830 ca. |
Thermocouple developed as measuring device: follows formulation of Seebeck and Peltier effects. |
15 |
| 1830 |
Bimetallic strips for temperature control, called thermostat: applied to distillation process. (Andrew Ure, Glasgow) |
15 |
| 1830 - 1839 |
Dynamometer invented. (Arthur Jules Morin, France) |
17 |
| 1831 |
Basic platform scale patented: improved 1868. (Thaddeus Fairbanks, Vermont) |
10 |
| 1833 |
Wheatstone bridge invented: used in strain-gauge circuits to measure resistance. (Samuel Christie, London) |
17 |
| 1837 - 1850 |
Instrumentation advances made, including velocity measurements of vessels, reflecting pyrometer, hydrometer, etc: mint machinery and coast survey apparatus developed (portrayed in MEN OF PROGRESS portrait by Christian Schussele, 1863). (Joseph Saxton) |
11 |
| 1838 ca. |
Gearless anemometer records wind pressure: first true self-registering scientific instrument. (A Follet Osler, Britain) |
14 |
| 1840 ca. |
Go and no-go gauge system developed: checks part size and aids interchangeability of parts. (Wm Thorton, US) |
13 |
| 1843 |
Dynamometer built. (Weber) |
17 |
| 1843 - 1865 |
Fatigue in metals studied by Scottish engineering professor Rankine. (Lewis Gordon, Wm J M Rankine, Scotland) |
17 |
| 1845 ca. |
Magnetometer used to detect submarines from the air. |
19 |
| 1848 |
Modern hand micrometer patented as Palmer's screw caliper. (J L Palmer, Paris) |
13 |
| 1848 |
Weisbach experiments with stress on machine parts; publishes MECHANICS. (Weisbach, Germany) |
17 |
| 1849 |
Bourdon's pressure gauge introduced for rail locomotives and hydraulic machines. (Eugene Bourdon, France) |
14 |
| 1850 |
Linear dividing machine built: first automatic machine for graduating rules in US. (Joseph R Brown, Providence, RI) |
13 |
| 1850 |
Photoelastic stress analysis techniques developed in two dimensions: uses glass. (James C Maxwell, Britain) |
17 |
| 1851 |
Vernier caliper introduced. (Joseph R Brown, US) |
13 |
| 1854 |
Fatigue, or creep, defined as result of mechanical failures. (J Braithwaite) |
17 |
| 1858 |
Strength of tubes, flywheels, and rail tracks and the bending of curved bars studied. (E Winkler) |
17 |
| 1858 |
Limits to metal fatigue (creep) described by railroad engineer: fatigue-testing machine used. (A Wohler, Hanover, Germany) |
17 |
| 1860 ca. |
First analytical laboratory for iron works established at Cambria Iron Company. (Robt W Hunt, Johnstown, Pa) |
17 |
| 1860 - 1869 |
Classic work on wrought iron girders for bridges: one of first uses of iron in structures. (Wm Fairbairn, Britain) |
17 |
| 1863 - 1865 |
Linear dividing machine, to rule scales, designed and built: corrector bar and lead screw. (Thury and de la Rive, Geneva) |
13 |
| 1864 |
British associated ohm issued: measures electrical quantities in mechanical units (1833, Gauss, and 1851, Weber) |
10 |
| 1864 |
Britain adopts metric system. (Britain) |
10 |
| 1864 |
Schlieren optical system developed: observation of density changes. (August Topler, Germany) |
19 |
| 1865 |
Materials testing laboratory established. (David Kirkaldy, London) |
17 |
| 1866 |
Metric system legalized and yard-metre ratio established by US Congress: adopted as fundamental standard in 1893. (US) |
10 |
| 1867 |
Concept of critical points pioneered. (Tschernoff) |
17 |
| 1868 |
Pocket micrometer mass produced: accurate to one-thousandth of an inch. (Brown and Sharpe, US) |
13 |
| 1868 |
Automatic scales for weighing grain charging into hopper patented: other improvements follow. (Thaddeus and Henry Fairbanks, Vermont) |
16 |
| 1868 |
Two-dimensional stress on a plane studied. (Otto Mohr) |
17 |
| 1871 - 1879 |
Materials testing laboratory established in Munich, Berlin, Vienna ('73), Zurich ('79), and Stuttgard('79). (Europe) |
17 |
| 1872 |
Towing tank technology established: law of similitude (comparing model with ship phenomena). (Wm Froude, Tourkay, UK) |
18 |
| 1873 ca. |
First US micrometer caliper for tool making. (John Edson Sweet, New York) |
13 |
| 1873 - 1879 |
Theory of least work and virtual work published: used for analysis of structures. (A Castigliano, Italy) |
17 |
| 1875 |
Treaty of the Metre signed by 21 countries, International Bureau of Weights and Measures: to define meter and kg. (Sevres, France) |
10 |
| 1875 |
Thompson indicator (for steam engine) patented. (Joseph Thompson, Ohio) |
14 |
| 1875 ca. |
Wind tunnel developed to study drag of vanes. (H F Phillips, Britain) |
18 |
| 1877 |
Hydraulic dynamometer improved Reynolds' hydraulic brake: measured steam power. (Wm Froude) |
17 |
| 1879 |
Hydraulic testing machine. (A H Emery, US) |
17 |
| 1880 - 1889 |
Metric system adopted by France: devised 1793, based on meter as a unit of 10. (France, US) |
10 |
| 1880 |
Thermostat sensitivity controlled: used for egg incubation. (C E Hearson, Britain) |
15 |
| 1880 |
Seismograph developed for quantitatively measuring earthquake phenonema. |
15 |
| 1880 ca. |
Crrent balance dynamometer using sliding mass. (Kelvin (Wm Thomson)) |
17 |
| 1880 |
Osmond first to use microscope to test metals at Le Creusot works. (F Osmond, Birmingham, UK) |
19 |
| 1881 |
Thury's circular dividing machine for the Societe Genevoise. (Marc Thury, Geneva) |
13 |
| 1884 |
Specifications for the testing of materials addressed by international congress. |
17 |
| 1885 |
Rogers-Bond universal comparator (early model) patented. (Wm Rogers, G M Bond, US) |
13 |
| 1886 |
36-inch telescope built for Univ of Calif Lick Observatory by Ambrose Swasey and Worcester R Warner. (Swasey and Warner, Chicago) |
19 |
| 1886 |
Venturi meter* for flow measure developed: continuous record of flow through pipes possible. (Clemens Herschel, Holyoke, Mass) |
14 |
| 1886 |
Edison moves his laboratory from Menlo Park to West Orange, NJ. (Thomas Edison, New Jersey) |
18 |
| 1887 |
Probe measurements introduced and cathode drop and anode drop established for arcwelding. (Lecher) |
10 |
| 1888 |
Floating dynamometer invented for measuring power delivered by dynamos and motors. (John Burkitt Webb, New Jersey) |
17 |
| 1889 |
International Prototype Metre adopted in France. (France) |
10 |
| 1889 |
Time recorders produced: first in world (eventually merged 1911 into IBM). (Bundy Company, US |
15 |
| 1890 |
Kilogram 20 defines US kilogram measure: according to International Bureau of Weights and Measures. (President B Harrison, US) |
10 |
| 1892 |
Viscous dynamometer invented. (John Burkitt Webb, New Jersey) |
17 |
| 1893 |
Digital micrometer invented: US rights acquired by Brown and Sharpe. (J Ciceri Smith, Edinburgh Univ, Britain) |
13 |
| 1896 |
Johansson blocks (precision block gauges) and slip-gauge system produced: by hand lapping method, introduced 1908. (Carl E Johansson, Eskilstuna, Sweden) |
13 |
|
20th Century |
|
| 1900 |
Dynomophone invented: twist of transmission shaft carrying power measured. (John Burkitt Webb, New Jersey) |
14 |
| 1900 ca. |
Wind tunnel for aerodynamic study developed: most notably by Wright brothers. (Wright brothers, Dayton, Ohio) |
18 |
| 1901 - 1912 |
Proliferation of industrial research laboratories: General Electric (1901), then Du Pont, Eastman Kodak (1912). (US) |
18 |
| 1903 |
Gyroscope-like flywheel device created to control damping the pitch and roll of ships. (Schlick, Germany) |
15 |
| 1904 |
Lathe-tool dynamometer used to measure cutting forces: hydraulic pressure used. (J R Nicolson) |
14 |
| 1907 |
International angstrom adopted as unit measurement in spectroscopy (ten thousand millionth of one metre). |
10 |
| 1908 |
Active stabilizer (gyrostabilizer) patented: becomes basic patent. (Elmer A Sperry, US) |
15 |
| 1908 |
Tensile and shearing strength computed (in AMERICAN MACHINIST grinding book). (F H Colvin and F A Stanley, US) |
17 |
| 1908 |
Alden Research Laboratory boom*. (Massachusetts) |
18 |
| 1909 |
Industrial measurement machine built: scale comparison to International Prototype Metre. (Societe Genevoise, Geneva) |
13 |
| 1914 - 1920 |
Gyropilot (automatic pilot) patent is filed 1914 and granted 1920. (Elmer A Sperry, US) |
15 |
| 1915 ca. |
Optical projectors used for gauge measurement. (E M Eden, Britain) |
13 |
| 1917 - 1918 |
10-inch Hooker telescope* built with deflection force mirror support and mercury flotation. (George Hale, Pasadena, Calif) |
19 |
| 1918 |
Machine lapping method introduced for producing precision block gauges. (W E Hoke, NBS, Washington, DC) |
13 |
| 1918 |
Eden-Rolt millionth comparator designed. (E M Eden, NPL, Britain) |
13 |
| 1920 - 1929 |
Diamond Pyramid and Rockwell hardness testers used to control heat in alloy production. |
17 |
| 1920 - 1939 |
Two-dimensional photoelastic stress analysis becomes popular. (E G Coker, London) |
17 |
| 1923 |
Interference comparator for gauge blocks manufactured by Zeiss. (Berndt and Kosters, Germany) |
13 |
| 1923 |
Optical engine indicators developed for aircraft. (Hopkinson) |
14 |
| 1923 |
Balanced-pressure-engine indicator for aircraft introduced: led to development of electronic engine indicators by 1940. (Farnboro) |
14 |
| 1925 ca. |
Payne's thermostat uses metallic bellow (1844, L Vidie, France) for automobile cooling. |
15 |
| 1926 |
Michelson interferometer devised (check 1881, Albert A Michelson, US: used in 1887 Michelson-Morley experiment--V9). |
19 |
| 1928 |
Quartz crystal clock invented. (Horton and Marrison, US) |
12 |
| 1928 |
Precision pneumatic micrometer invented to measure internal dimensions of objects. (Marcel Mennesson, France) |
13 |
| 1929 |
Text on gauges and fine measurements published. (F H Rolt, NPL, London) |
13 |
| 1930 |
Geiger torsiograph used for continuous recording of vibration on a rotating drum. |
17 |
| 1930 ca. |
Blind-flying instruments developed for safe air flight: artificial horizon, turner indicator, etc. |
19 |
| 1933 |
Vertical metroscope designed for industrial measuring: for Zeiss. (Otto Eppenstein, Germany) |
13 |
| 1939 ca. |
Electronic engine indicators for aircraft introduced. |
14 |
| 1940 - 1949 |
Electrical resistance strain gauges develop in US to measure structures under loading. (US) |
17 |
| 1940 - 1949 |
Electrical resistance strain gauges develop in US to measure structures under loading. (US) |
17 |
| 1941 - 1944 |
Wind tunnel to test jet engine built: drives a 24-ft-dia single-stage 16-blade fan. (Boeing, US) |
17 |
| 1942 |
Triplett and Barton automatic industrial x-ray unit (Model 40-1) patented (developed 1940 ca). (Ralph H Swaisgood, US) |
17 |
| 1943 |
Aberdeen Aerodynamic Range begins operations: experiments in ballistic measures for projectiles for military and aeronautical appliations, innovations include high-speed spark photography. (Maryland) |
17 |
| 1944 |
Sonigage patented and demonstrated: NDT, basic patent on ultrasonic resonance testing (General Motors). (Wesley S Erwin, US) |
17 |
| 1944 |
Supersonic reflectoscope manufactured by Sperry Products Inc: begins NDT instrumention. (Floyd A Firestone) |
17 |
| 1945 |
Rotating-arm ship-model test facility experiments with forces and control measurements. (Kenneth Davidson, Hoboken, Stevens Institute) |
18 |
| 1946 |
Audigage thickness tester demonstrated: tests (NDT) tetraethyl lead tanks in Texas and Calif also. (Norman Branson, New York) |
17 |
| 1946 - 1953 |
Ultrasonic immersion tester developed: for NDT of turbine blade, welding, inspection, etc. (Donald Erdman) |
17 |
| 1947 ca. |
Hypersonic research tunnel built at Lewis Research Center. (Lewis Research Center, Cleveland) |
18 |
| 1947 ca. |
Supersonic wind tunnel built at Langley Aeronautical Laboratory of NASA. (Langley, Virginia) |
18 |
| 1948 - 1960 |
Krypton wavelength and vacuum wave length of cadium red adopted to define metre. |
10 |
| 1948 |
Electronic comparator (measuring machine) introduced into machine tool shops. |
13 |
| 1948 |
Palomar Observatory operates 200-inch telescope. |
19 |
| 1950 ca. |
Photoelastic properties of plastics lead to frozen stress technique and stress analysis. |
17 |
| 1950 ca. |
Ultrasonic Hitt blocks devised: calibrated distance amplitude measurements (aerospace NDT). (ALCOA, US) |
17 |
| 1950 ca. |
Gigantic radio telescope built at Jodrell Bank: capable of tracking space flights. |
19 |
| 1953 |
Taper gauges for ultrasonic thickness evaluation and hand-scan system for immersion testing developed (NDT). (Wm C Hitt, Van Nuys, Calif) |
17 |
| 1954 |
Maser (microwave spectrum) device built and operated as spectrometer. (Gordon, Zeiger, and Townes) |
17 |
| 1955 - 1959 |
A-, B-, and C-scan systems for ultrasonic (NDT) testing developed (Saltronics Company). (Ultransonic Testing and Research Laboratory, Van Nuys, Calif) |
17 |
| 1958 |
Inertial guidance used as sole navigation aid: USS NAUTILUS travels under polar icecap. (US) |
19 |
| 1958 |
Laser, called infrared and optical maser at first, invented. |
19 |
| 1959 |
Electronic coordinate measuring machine (CMM) measures large complex objects at Ferranti. (Britain) |
13 |
| 1960 |
Comparator with interferometer and photoelectric scanning microscopes introduced. (Societe Genevoise, Europe) |
19 |
| 1960 - 1962 |
Helium-neon laser created: emits continuous beam of light (researched 1958). (A Javan, Bennett, Bell Labs, US) |
19 |
| 1962 |
Stanford Linear Accelerator built: subatomic particles and forces studied. (California) |
18 |
| 1963 |
Holograms demonstrated with laser: holographic interferometry applied to precision measuring. (Univ of Mich, US) |
19 |
| 1963 |
Lamb dip for high-resolution spectroscopy discovered. (Willis E Lamb, Jr, US) |
19 |
| 1965 ca. |
Acoustic-emission (stress-wave analysis technique, SWAT) NDT of solid rocket motor case developed. (US Navy, R K Steele, US) |
17 |
| 1965 ca. |
Radio telescope at Jodrell Bank tracks space flights. (Britain) |
19 |
| 1968 |
Field inspection using acoustic-emission NDE truck perfected: based on SWAT (1965 ca). (Carroll Morais, US) |
17 |
| 1970 |
Tunable laser (form of saturation spectroscopy) introduced, independently. (C Borde, T W Hansch) |
19 |
| 1972 |
Acoustic emission NDT equipment demonstrated at Experimental Beryllium Oxide Reactor. (Edison Electric Institute, Idaho Falls, Id) |
17 |
| 1973 |
Nuclear magnetic resonator introduces new generation of diagnostic equipment. |
17 |
| 1975 |
Metric Conversion Act of 1975 signed into law. (US) |
10 |
