Shozo TANAKA, who was trying to pin down the pollution caused by the Ashiodozan Copper Mine, valued Iba's achievements and referred to the Besshidozan Copper Mine as the 'roll model that every Japanese copper mine should follow.'
足尾銅山の鉱害を追及していた田中正造も伊庭の一連の行動を評価し、別子銅山を「我が国銅山の模範」とまで言い切っている。