▁D ah ll , ▁who ▁was ▁a ▁mill - ▁and ▁ship - owner . ▁ ▁The ▁brothers ▁were ▁both ▁influ ential ▁ge olog ists ▁in ▁their ▁own ▁right , ▁but ▁T elle f ▁in ▁particular ▁was ▁an ▁important ▁figure ▁in ▁Norway ' s ▁history . ▁ ▁T elle f ▁D ah ll ▁was ▁known ▁for ▁his ▁work ▁in ▁ge ological ▁surve ying ▁and ▁standing ▁as ▁St ort ing et ▁member ▁for ▁Br ats berg ▁( now ▁Te lem ark ), ▁and ▁he ▁was ▁later ▁made ▁a ▁kn ight ▁in ▁both ▁the ▁Order ▁of ▁St . ▁O lav ▁and ▁the ▁Order ▁of ▁the ▁Pol ar ▁Star . ▁ ▁Though ▁the ▁D ah ll ▁brothers ' ▁operation ▁was ▁smaller ▁than ▁the ▁Comp ag nie ▁Fran çaise ' s , ▁employ ing ▁only ▁ 4 6 ▁men ▁overall , ▁it ▁f ared ▁slightly ▁better ▁in ▁the ▁final ▁years ▁of ▁the ▁ 1 9 th ▁century . ▁ ▁In ▁ 1 8 9 5 , ▁while ▁the ▁ Ø st gru ven ▁mines ▁were ▁for ▁the ▁most ▁part ▁shut ▁down , ▁Johan ▁D ah ll ▁export ed ▁ 1 , 2 0 0 ▁t onnes ▁of ▁ap at ite , ▁ear ning ▁ 6 5 ▁k ron er ▁per ▁t onne ▁for ▁the ▁highest - p urity ▁of ▁these ▁ship ments . ▁ ▁A pat ite ▁samples ▁from ▁the ▁D ah ll ▁mine ▁were ▁among ▁the ▁min er als ▁presented ▁as ▁part ▁of ▁Norway ' s ▁exhib it ▁at ▁the ▁ 1 8 7 6 ▁Cent enn