. ▁ ▁External ▁links ▁ ▁Arch ae om agnet ic ▁Labor atory ▁at ▁the ▁Illinois ▁State ▁Museum ▁ ▁The ▁U . ▁S . ▁National ▁Ge oph ys ical ▁Data ▁Center ▁( NG DC ) ▁data ▁of ▁pale op ole ▁positions ▁and ▁pale om agnet ic ▁directions . ▁ ▁Y ale ▁University ▁Arch ae om agnet ism ▁Labor atory ▁ ▁Further ▁reading ▁ ▁Six ▁centuries ▁of ▁geom agnet ic ▁intensity ▁variations ▁recorded ▁by ▁royal ▁J ude an ▁stamp ed ▁jar ▁handles . ▁ ▁Category : In crement al ▁d ating ▁Category : P ale om agnet ism <0x0A> </s> ▁Duc ati ▁Motor ▁Hold ing ▁S . p . A . ▁() ▁is ▁the ▁motor cycle - man ufact uring ▁division ▁of ▁Italian ▁company ▁Duc ati , ▁head qu arter ed ▁in ▁Bolog na , ▁Italy . ▁The ▁company ▁is ▁owned ▁by ▁German ▁autom ot ive ▁manufact urer ▁A udi ▁through ▁its ▁Italian ▁subs idi ary ▁Lamb org h ini , ▁which ▁is ▁in ▁turn ▁owned ▁by ▁the ▁Volks wagen ▁Group . ▁ ▁History ▁In ▁ 1 9 2 6 ▁Antonio ▁Caval ieri ▁Duc ati ▁and ▁his ▁three ▁sons , ▁Adri ano , ▁Marcel lo , ▁and ▁Bruno ▁Caval ieri ▁Duc ati ▁founded ▁Soci età ▁Scient ifica ▁Radio ▁Bre v etti ▁Duc ati ▁in ▁Bolog na ▁to ▁produce ▁vac u um ▁tub es , ▁cond ens ers ▁and ▁other ▁radio ▁components . ▁In ▁ 1 9 3 5 ▁they ▁had ▁become ▁successful ▁enough ▁to ▁enable ▁construction ▁of ▁a ▁new ▁factory ▁in ▁the ▁Borg o ▁Pan