history metric system concepts similar metric system discussed 16th 17th centuries published ideas published proposal system measurement based natural units practical metric system came french revolution existing system measure fallen temporarily replaced system based kilogram metre work reforming old system weights measures support power including metric system words philosopher mathematician people time era basic units taken natural world unit length metre based dimensions earth unit mass kilogram based mass water having volume cubic metre reference copies units manufactured placed custody new metric system france reverted measurement system units similar old system metric system adopted france half 19th century adopted scientific community middle century forward concept coherent system small number units measure defined base units units measure called derived units defined terms base units proposed base units length mass time concept worked mechanics attempts describe electromagnetic forces terms units encountered difficulties end 19th century principal variants metric system use measurement electromagnetic phenomena based second system units system metre kilogram second system units system resolved proved coherent system incorporated electromagnetic units electromagnetic unit fourth base unit french government owned prototype metre kilogram year convention metre signed control standards relating mass length passed trio inter governmental organisations senior french des half 20th century number organisations responsibility defining temporal electrical thermal molecular measurements international organisations continued roles units measurement launched french international base units metre kilogram second degree subsequently renamed units derived base units mole added seventh base unit period metre terms waves particular light source second defined terms frequency radiation light source end 20th century effort undertaken kilogram mole terms basic physics development underlying principles practical implementation metric system system implemented end 18th century key features nature derived unit sizes nature units different dimensions related rational manner denote sub units features explored scholars academics centuries prior french metric system implemented credited introducing system general use europe twentieth century writers france united_kingdom credit french metric system proposal coherent system measurement english received publicity writers focused proposals gave equal coverage quinn makes mention states proposed essentially french metric system work simon early medieval era roman europe represent numbers arabs represented numbers hindu system symbols published book book calculation introduced concept europe symbols evolved etc time dispute difference rational numbers numbers consistency way represented published small pamphlet called tenth historians credit basis modern felt innovation significant declared universal introduction measures weights merely question time work mid seventeenth century secretary england asked society universal standard measure attempted knowledge page book essay real character philosophical language pages chapter vii devoted physical measurement proposed system units measure based called universal measure derived nature use learned men nations considered earth atmospheric pressure following suggestion demonstrations source universal measure discarded atmospheric pressure candidate described susceptible variation link atmospheric pressure weather understood time discarded difficult measure leaving preferred choice proposed length seconds approximately named standard basis length proposed measure capacity base unit volume defined cubic standard measure weight base unit weight mass weight cubic standard sub measures related base measure manner short proposed essentially french metric system work french abbot published book proposed system measurement length use scientists international communication based dimensions earth defined minute arc divided successive units estimate degree arc feet experiments showed length beat times half hour current theory shows equivalent length today knowledge size earth approximately believed information scientists foreign country able construct copy use 17th century developments communication information issues facing mid seventeenth century discussed possibility scholarly communication called universal measure tied particular national system measurement ideas attracted interest time work work proposing standard unit length tied beat frequency interest experiments effectively announced work length second measured number locations outside france island north copenhagen measured north equator difference paris difference lengths paris cooperation showed difference measured london paris measurements taken west_africa line taken england work essay concerning human understanding references philosopher foot defined second latitude englishman newton book gave theoretical explanation equator explained differences found lengths second theories confirmed expedition peru 18th century international cooperation late eighteenth century proposals similar seventeenth century universal measure common international system measure spheres commerce technology implemented system drew seventeenth century proposals early ninth century later france units measure introduced standard units measure length mass empire empire separate nations including france standards diverged estimated eve revolution quarter million different units measure use france cases quantity associated unit measure differed town town trade trade certain standards king foot degree pre scientists traders chose use measuring devices giving scope fraud commerce industry variations promoted local interests hindered trade taxation contrast stipulated shall unit measure realm mid eighteenth century apparent weights measures nations traded exchanged scientific ideas necessary spain example aligned units measure royal units france aligned russian units measure england british inventor having difficulties communicating german scientists called creation global measurement system proposing system like seventeenth century proposal density water link length mass french chemist commissioned set brass cylinders french pound subdivisions thereof experimental work french finances state years poor resulted hunger peasants reforms thwarted interests summoned estates general triggering series events french revolution june newly formed took oath constitution drafted resulting setting june day des sciences set committee investigate reform weights measures diverse nature vehicle corruption august weeks nobility surrendered privileges including right control local weights measures representative clergy revolutionary leader prompting mathematician secretary approached british americans early proposals joint effort define common standard length based length great_britain represented united_states represented agreed principle proposal choice latitude proved sticking point jefferson opting london latitude proposal new measure defined latitude preferred won support parties concerned july jefferson presented document plan establishing weights measures united_states like advocated system units traditional names inches feet related powers like proposed system weights based weight cubic unit water unlike proposed rod bob miller promoted proposal response proposal set new committee auspices investigate weights measures members able scientists day committee having decided counting weights measures use debated use system alternative system eventually committee decided advantages complications introducing system october recommended currency weights measures based system argued favour time angular measures committee examined possible standards length length beat frequency second latitude quarter length equator quarter length committee proposed standard weight weight water held cube sides proportion standard length committee final report march recommended definition unit length inventor repeating circle appointed chairman proposal accepted march jefferson report considered adopted lost british parliamentary seat election french later monarchy britain withdrew support france decided roles past writers france united_kingdom credited founding father metric system late australian metric investigated proposal universal system measurement essay work pre dated proposal years proposal unlike discussed integrated measurement system encompassed length volume mass length widely circulated time main interest essay proposal philosophical language general universal standard units measure subsequent interest confined mainly interested field example introduction noted leading seventeenth century works british commentators essay devoted little space proposals measurement passing comment section measurements page study essay page study essay comments measurements proposals taken seriously seventeenth century scientists years french took interest underlying theory development systems measure shortly introduction metric system french letter anonymous regular contributor noted lack french publication writer accused editors giving attention work expense proposed earth standard proposed measurement system took british writers task defending went note considerable communication scientists channel particularly visiting members implementation revolutionary france accepted committee report march des sciences instructed implement proposals broke tasks operations separate working group measuring difference latitude barcelona measuring survey length second latitude weight given volume water publishing conversion tables relating new units measure existing units measure june day flight obtained royal audience king agreed fund measurement repeating measurements father king authorization arrived june political turmoil followed king flight reform weights measures particular measurement continued albeit structure commission changed changing political climate loyal revolution replaced july commission formally proposed names metre etc assembly executed january august year eve reign terror new facto government executive suppressed commission requiring justify existence member convention argued importance reforming weights measures work commission allowed continue september commission commission april metric system formally defined french law provisional standards based survey adopted october work commission man taken newly formed science new government transferred minister interior november returned paris data having completed survey barcelona data analysed prototype metre constructed platinum length time prototype kilogram constructed mass cube water cube metres prototype metre presented french legislative assemblies june time decree october introduced republican calendar france time day divided hours hour minutes minute seconds hour corresponded min minute min second revolutionary week days months year month consisting weeks year days total days implementation time proved immense task article law april use time longer mandatory republican calendar retained january france reverted traditional angular measure specific decree angular measure reported mentioned metric system decree particular repeating circle invented strong proponent adapted use angles grade gon defined quadrant making grades circle grade standard metric quadrant making approximately kilometre adoption grade community sufficient warrant mention use continued military maps nineteenth century twentieth century appears widely outside angular measure adopted general use number countries general conference weights measures recommended degree measurement temperature renamed degree notes gon little alternative degree draft metric system france metric system measure given legal basis french revolutionary government article law april defined new units units preliminary values metre length defined distance equator paris area land volume volumes liquid mass defined mass cubic water currency units defined greek defined latin survey provisional value assigned metre turn defined units measure final value metre defined presented results survey barcelona fixed length metre law viii december defined metre terms value grains definitions enabled reference copies kilograms metres constructed standards years definition question measurement reform france placed hands appointed commission chaired said fanatic designed repeating circle surveying instrument allowed improved precision measurement angles landmarks insisted grades quarter circle degrees minutes grade seconds minute instrument manufactured seconds poor choice standard second unit time preferred new system hours day minutes hour seconds minute instead commission members included decided new measure equal distance equator quadrant earth measured passing paris apart obvious considerations paris sound choice practical scientific reasons portion quadrant barcelona tenth total surveyed end points sea level portion roughly middle quadrant effects earth expected largest task surveying arc authorized estimated years fell task eventually took years delays caused technical difficulties period aftermath revolution meantime commission calculated provisional value older surveys project split parts northern section surveyed southern section barcelona surveyed length straight road located close operation taking weeks accurately measured platinum rods length possible points survey france similar length straight section road area sector half length included hitherto parts spain met order cross check results kilometre result came shorter provisional value difference completing survey commission ordered series platinum bars based provisional metre final result known bar length closest definition metre selected placed june vii republican calendar permanent record result standard metre bar known des archives metric system system units based metre officially adopted france december viii sole legal system weights measures soon apparent result slightly short definition metre extended survey island western mediterranean_sea found earth quadrant later work increased value modern value reference des archives remained legal practical standard metre france known exactly correspond definition proposed new international standard metre created length taken des archives state shall found april kilogram based decreed equal absolute weight volume pure water equal cube metre temperature melting ice definition regulation trade commerce required practical single piece metallic reference standard thousand times massive known grave mass unit derived word gravity defined use notwithstanding definition base unit mass alternatively new practical ultimately base unit mass provisional kilogram standard work commissioned determine precise mass cubic later defined equal water decreed definition specified water highly stable temperature point scientists tasked producing new practical chose standard perform measurements stable density point temperature water reaches maximum density measured time concluded cubic water maximum density equal mass provisional kilogram earlier year years later platinum standard des archives fabricated objective equal close scientifically feasible day mass cubic water defined equal mass standard stood ninety years note new metric system come effect france french revolution new revolutionary government captured idea metric system decision republican government new unit mainly politically motivated grave time considered politically incorrect resembled aristocratic german title alternative title count like nobility titles inconsistent new notion equality accordingly original defined unit mass small serve practical adopted new prefix form consequently kilogram base unit prefix unit adoption metric weights measures nineteenth century metric system weights measures proved convenient political compromise unification processes netherlands germany italy portugal country officially adopt metric system spain found follow french example decade latin_america adopted metric system considerable resistance united_kingdom united_states united_kingdom announced program commonwealth followed suit france introduction metric system france district district basis paris district modern standards transition poorly managed thousands pamphlets distributed agency weights measures oversaw introduction work involved paris needed metre sticks month metre sole legal unit measure store combined revolution high level metric system unpopular napoleon ridiculed metric system able administrator recognised value sound basis system measurement imperial decree february new system measure customary measures introduced use small retail businesses government legal similar works use metric system metric system continued taught levels education names units regime reintroduced terms metric units defined metres making making making likewise defined comprising sixteen centimetres means law july effectively revoked use laws measurement units measure half kilogram remained use years portuguese metric system august portugal officially adopted metric system names units substituted portuguese traditional ones system basic units hand yard metre canada pound kilogram dutch metric system netherlands metric system french empire royal decree march van den newly formed kingdom netherlands abandoned favour dutch metric system metric units given names units measure use examples include defined outbreak french revolution modern day germany austria loose federation kingdoms free cities system measurement cases system loosely derived system instituted thousand years earlier napoleonic era german states reform systems measurement prototype metre kilogram basis new units example rods exactly defined feet inches lines points defined divided bavaria reform trimmed exactly consisting prussian remained congress vienna degree commercial cooperation german states resulting setting barriers trade bavaria took lead establishing code introduce customs pound defined exactly split lot unit inter state movement goods applied states internal use collapsed austro prussian war metric system official system measurement newly formed austria ceased legal germany italy north italian republic set napoleon capital milan adopted modified form metric system based defined half metre republic renamed napoleon head state following year system measure replaced metric system replaced napoleon emperor italy rome northwards control napoleon french departments ensuring metric system use region congress vienna italian states reverted original system measurements passed legislation introduce metric system years italy unified law july metric system official system measurement kingdom numerous displayed shops december spain ascent monarchy spain regions spain retained system measurement new monarchy tried control system measurement debates retaining units measure interests adopting french system spain assisted survey government feared french revolutionary movement reinforced units measure counter movements proved difficult maintain old system year metric system legal system measure spain united_kingdom commonwealth weights measures act imposed standard imperial system weights measures british_empire effect act existing british units measure align metric system eighty years number parliamentary select committees recommended adoption metric system greater degree urgency parliament report recommended compulsory intermediate phase parliament responded metric units contracts dealings initially united_kingdom declined sign treaty metre british scientists forefront movement promoted system units coherent system british firm accepted cast international prototype metre kilogram parliamentary select committee recommended compulsory adoption metric system year period weights measures act metric units trade mandatory bill metric system compulsory order enable british industrial base fight challenge nascent german base passed house_of_lords pass house_of_commons general election called following opposition lancashire cotton industry similar bill defeated house_of_commons votes britain commenced official program completed british program signalled start programs commonwealth india started program years united_kingdom south_africa member commonwealth set new_zealand set australia passed metric conversion act canada appointed australia new_zealand south_africa essentially complete decade india canada complete addition widespread use india commonwealth countries adopted metric system 1970s united_states united_states government acquired copies french metre kilogram reference purposes respectively passed bill making use metric system united_states bill mandatory nature defined metric system terms customary units reference international prototype metre kilogram reference standards customary units unreliable united_states possession national prototype metres kilograms use world led customary units referring national metric prototypes conversion factors act bill metric system mandatory united_states presented congress people gave evidence congressional committee considering bill favour bill represented manufacturing interests service grounds cited cost change bill enacted subsequent bills suffered similar fate development coherent metric system inception metric system designed manner units measure linked start nineteenth century length mass time temperature base unit units defined terms formal standards beginnings coherent system place units area volume linked unit length time science understand concepts base units derived units physical quantities inter related concept enabled thermal mechanical electrical systems formally proposed length mass time base units absence electrical base unit resulted number different electrical systems developed half nineteenth century need unit resolve problems identified standard published defined single coherent system based units time work energy absolute measurements earth magnetic field system based use millimetre second base unit time paper presented results metre instead millimetre line berlin pound instead millimetre paper published demonstrated means measuring energy transferred different systems work relating defined mechanical work energy concept nineteenth century science initially bringing mechanics later adding electrical technology physics leading equation formula unit energy unit energy named honour committee including later lord members tasked investigating standards electrical resistance report laid ground rules work metric system measures electrical energy units measures mechanical energy sets electromagnetic units derived electromagnetic system system second report introduced concept coherent system units units length mass time identified fundamental units known base units units measure derived derived units base units metre second chosen base units committee counted members tasked selection nomenclature electrical units recommended system units committee recommended names units force energy system basis scientific work seventy years electrical units 1820s formulated law extended relate power current potential difference voltage resistance following decades coherent system units incorporated measurement electromagnetic phenomena law problems different systems units devised systems formula formula consequently formula formula electromagnetic system units electromagnetic system units developed discovery 1820s relationship force current carrying relationship known law written formula formula units pointed possibility force mechanical equivalent proposal received support electromagnetic absolute system units systems units identified report defined report system current defined setting magnetic force constant formula unity potential difference defined way ensure unit power calculated relation formula identical unit power required mass distance second opposed force electromagnetic units measure known system units system units based discovery relationship force exerted charged bodies relationship known law written formula formula units system second systems units identified report defined report system unit charge defined setting force constant formula unity unit potential difference defined ensure unit energy calculated relation formula units measure known system units system units based realization system electromagnetic units related system units relationship formula relationship proposed merging systems system units magnetic quantities subsequently named units named combined set units units set units recognised particularly useful theoretical physics practical system units units measure scientific work practical engineering leading development practical system electric units time system units proposed dimension electrical resistance modelled system ratio system unit length adopted practical system approximately length earth quadrant unit time second unit mass unnamed unit equal definitions electrical units based system names values carried system system adopted second congress defined practical units energy power respectively units congress chicago formally defined units names close identical practical units coherent system electrical units measure easily fit coherent system length mass time base units proposed paper dimensional analysis dimensions voltage defined system units identical dimensions current defined system units formula resistance dimensions velocity system units dimensions velocity system units onwards oliver corresponded results led presenting paper congress october showed coherent electro mechanical system units obtained adding fourth base unit electrical nature base units proposed report gave physical dimensions electro mechanical quantities given physical dimensions work recognized concept energy played establishment coherent rational system units unit energy electrical units practical system units remaining unchanged definitions led defined accordance resolutions larger defined accordance artefacts units measure defined word international international international etc took thirty years work accepted practice formally adopted definition based original definition terms base units proposals adopted basis international international system units naming units measure proposed names honour respectively practical units based second absolute system supported lord names later scaled use practical system concept naming units measure noteworthy scientists subsequently units convention metre increasing international adoption metre short des archives standard apparent countries adopted metre legal measure purchased standard metre bars intended equal length des archives systematic way ensuring countries actually working standard definition intended ensure international quickly proved impractical abandoned favour standards des archives copies end standards standards bars exactly metre length prone wear use different standard bars expected wear different rates called creation new international prototype metre arrange system national standards compared international prototype line standard metre defined distance lines marked bar avoiding wear problems end standards french government gave practical support creation met paris participation thirty countries international treaty known convention metre convention signed states treaty established following organisations conduct international activities relating uniform system measurements des general conference weights measures conference official delegates member nations supreme authority actions international des consisting selected scientists prepares decisions responsible supervision bureau international des permanent laboratory world centre scientific activities include establishment basic standards scales principal physical quantities maintenance international prototype standards oversight regular comparisons international prototype national standards international prototype metre kilogram platinum exceptionally hard good electrical thermal properties prototype special shaped cross section effects strain length comparisons prototype kilograms cylindrical shape london firm delivered prototype metres prototype kilograms meeting bar cylinder accepted international prototypes remainder kept working copies distributed member states national prototypes twentieth century beginning twentieth century custody artefacts define length define mass units measure rely specific artefacts controlled bodies scientific world quantum theory infancy publish theories end century coherent system units place control bodies set treaty metre definition second relied quantum theory definition metre relied theory plans international prototype kilogram archives metre follow comparison national standards international prototype metre carried indicated definition metre preserved follow comparison way prototype metre measured clearly defined definition defined metre length prototype definition melting ice 7th extended definition specify prototype metre shall supported cylinders diameter placed horizontal plane distance choice represents points prototype points bending bar proposed use optical measurement length work contributed awarded nobel prize proposed use specific light source standard defining length accepted proposal radiation corresponding transition specified energy levels new standard metre second defined terms physical phenomenon earth rotation assertion speed light constant authorised investigate use speed light basis definition metre proposal accepted kilogram definition kilogram remained unchanged twentieth century 3rd clarified kilogram unit mass weight original batch prototypes adopted supplemented time time prototypes use new signatories course century national prototypes kilogram initial starting value national prototypes relative subsequent mass changes relative technique steam cleaning prototypes remove developed second periodic revealed average difference adjusted national prototypes national prototypes adjusted difference zero definitive kilogram way telling losing mass national prototypes gaining mass time advent atomic clock reliable available mankind earth rotation natural took lead maintaining standards relating time responsibility passed took role coordinating number atomic scattered globe twentieth century apparent earth rotation slowing resulting days longer century verified comparing calculated sun observed antiquity going chinese records 10th instructed prepare definition second definition published stating second calculated earth speed naval observatory determined relationship frequency radiation corresponding transition levels ground state estimated rate rotation earth value adopted 13th electrical units treaty metre extended cover electrical units merging work 8th need replace international electrical units absolute units raised proposal proposal adopted accepted decision electrical unit fourth base unit proposed world war prevented definitions absolute electrical system based temperature start twentieth century fundamental laws formulated techniques existed measure temperature techniques scientific understanding nature temperature minimal produced theories describing inter temperature pressure volume gas microscopic scale understanding microscopic quantum nature temperature metric system temperature expressed degrees definition ice melted standard atmospheric pressure water boiled series tables defined temperature terms inter related measurements devices charged producing coherent system units measure definitions relating temperature clarified 9th temperature scale renamed temperature scale scale fixed defining triple point water left formal definition absolute zero 10th assigned absolute temperature scale triple point water defined 13th degree renamed ensuing years developed maintained cross relating measuring devices light like equivalent temperatures increasingly use reference point appears likely temperature terms constant triple point water prior french title conjunction produced standard intensity replace national standards standard defined temperature platinum new candles square ratified adopted base unit definition proved difficult implement definition revised reference radiation source replaced defining candles terms power specified visible light agreed program cooperation taking lead defining use units measure taking lead defining behaviour human eye mole mole originally known substance measured grams divided atomic weight originally differing views definition atomic weight assigned value atomic mass units oxygen defined oxygen terms assigned mixed proportion occur nature finally agreement brought end parties agreeing define atomic weight exactly agreement confirmed recommended inclusion base unit 14th 9th met years 8th response formal requests french government establish practical system units measure requested prepare recommendations single practical system units measurement suitable adoption countries time formally adopted recommendation writing printing unit symbols numbers recommendation recommended symbols important units measure time recommendations concerning derived units draft proposal extensive revision metric unit definitions symbols terminology based system units 10th accordance proposals recommended base unit derived definitions previously use discarded units derived units based metre second kilogram negotiations base units degree proposed base units system international adopted 11th years followed definitions base units particularly realise definitions refined proposed revision unit definitions metre kilogram remained base defined physical example clear divergence prototype kilograms observed 23rd meeting mandated investigate use natural basis units measure artefacts use meeting held reading united_kingdom september resolution draft changes presented meeting october agreed principle proposals forward addition speed light nature constant elementary charge constant number defined exact values international prototype kilogram retired current definitions kilogram mole revised wording definitions base units meeting october found conditions set 23rd meeting fully met reason propose revision present time presented resolution consideration 24th october agree new definitions principle implement details finalised resolution accepted conference addition moved date 25th meeting forward
History of the metric system