As a result of the introduction of Western modern mining technology, Ashio copper mine became Japan's largest copper producer and became the largest in East Asia which produced thousands of tons annually. さらに西欧の近代鉱山技術を導入した結果、足尾銅山は日本最大の鉱山となり、年間生産量数千トンをかぞえる東アジア一の銅の産地となる。 |