▁company ▁that ▁was ▁at ▁the ▁time ▁the ▁largest ▁private ▁min ing ▁enter prise ▁in ▁Norway . ▁ ▁A ▁year ▁later , ▁the ▁D alls ▁field ▁mines ▁opened ▁nearby ▁under ▁the ▁ownership ▁of ▁Kra ger ø ▁firm ▁named ▁Johan ▁D ah ll . ▁ ▁French ▁ Ø st gru ven ▁mines ▁When ▁the ▁Comp ag nie ▁Fran çaise ▁first ▁started ▁min ing ▁in ▁ 1 8 7 2 , ▁the ▁operations ▁were ▁super vised ▁by ▁director ▁August e ▁D aux , ▁who ▁lived ▁in ▁large ▁house ▁nearby ▁that ▁he ▁named ▁D aux borg . ▁In ▁ 1 8 7 7 , ▁D aux ▁was ▁succeeded ▁by ▁the ▁Franco - N or weg ian ▁min ing ▁engineer ▁Charles ▁Antoine ▁Del g obe , ▁who ▁ran ▁the ▁mines ▁until ▁ 1 8 8 6 . ▁Un like ▁D aux , ▁Del g obe ▁made ▁an ▁effort ▁to ▁learn ▁the ▁Norwegian ▁language , ▁which ▁made ▁him ▁more ▁capable ▁of ▁easily ▁communic ating ▁with ▁the ▁min ers . ▁ ▁Del g obe ▁would ▁continue ▁living ▁in ▁Norway ▁until ▁his ▁death ▁in ▁ 1 9 1 6 , ▁and ▁by ▁that ▁time ▁he ▁was ▁an ▁influ ential ▁Norwegian ▁gene alog ist , ▁civil ▁engineer ▁and ▁vice ▁cons ul ▁to ▁Belg ium . ▁ ▁Under ▁the ▁management ▁of ▁Del g obe , ▁ Ø st gru ven ▁was ▁among ▁the ▁largest ▁min ing ▁operations ▁in ▁the ▁country : ▁in ▁ 1 8 8 0 , ▁they ▁had ▁ 3 5 0 ▁workers ▁in ▁their ▁employ . ▁ ▁However , ▁a