| Moreover, in 1884, he purchased the Kosaka Mine (Akita Prefecture) from the government and, by focusing on technical innovation, had turned it into Japan's most productive copper and silver mine by the early 1900s. |
さらに17年、小坂鉱山（秋田県）の払い下げを受けると、技術革新に力をいれ、明治30年代後半には、銀と銅の生産で日本有数の鉱山に成長させた。 |