ial ▁Ex position ▁in ▁Philadelphia . ▁ ▁United ▁ Ø deg år den ▁Ver k ▁▁ Ø deg år den ▁Ver k ▁was ▁combined ▁into ▁a ▁single ▁operation ▁in ▁ 1 9 1 0 , ▁when ▁a ▁cons ort ium ▁led ▁by ▁H å kon ▁Math iesen ▁bought ▁both ▁mines ▁and ▁res umed ▁production . ▁ ▁In ▁ 1 9 1 5 , ▁Math iesen ▁and ▁the ▁other ▁own ers ▁formed ▁the ▁limited ▁company ▁B am ble ▁A pat itt ▁A / S ▁to ▁run ▁the ▁operation . ▁Er land ▁E ide ▁had ▁the ▁role ▁of ▁mine ▁super visor ▁during ▁this ▁time . ▁ ▁The ▁mine ▁saw ▁a ▁huge ▁ups wing ▁in ▁demand ▁during ▁First ▁World ▁War , ▁as ▁millions ▁of ▁European ▁far mers ▁were ▁draft ed ▁into ▁the ▁army . ▁ ▁With ▁fewer ▁workers ▁to ▁work ▁the ▁fields ▁and ▁an ▁sky ro cket ing ▁demand ▁for ▁cheap ▁food , ▁far mers ▁had ▁to ▁become ▁more ▁cre ative , ▁using ▁more ▁agricult ural ▁mach in ery ▁combined ▁with ▁synth etic ▁fert il izers ▁to ▁increase ▁the ▁rate ▁of ▁production . ▁ ▁While ▁the ▁Norwegian ▁government ▁was ▁officially ▁neutral ▁during ▁World ▁War ▁I , ▁they ▁saw ▁the ▁need ▁for ▁increasing ly ▁efficient ▁food ▁production , ▁and ▁as ▁such ▁they ▁attempted ▁to ▁run ▁several ▁similar ▁min ing ▁and ▁prospect ing ▁operations ▁in ▁the ▁district . ▁ ▁Also ▁in ▁the ▁early ▁ 1 9 0 0 s , ▁the ▁Nor sk ▁H ydro ▁fert il izer ▁plants ▁were ▁built ▁that ▁were ▁a ▁large ▁and ▁direct ▁compet