(704) An Act amending the "Pennsylvania Bituminous Coal Mine Act," approved July 17, 1961 (P. L. 659, No. 339), removing a provision relating to steam locomotives; and prohibiting the use of internal combustion engines in underground coal mines. (705) An Act amending the "Pennsylvania Anthracite Coal Mine Act," approved November 10, 1965 (P. L. 721, No. 346), prohibiting the use of internal combustion engines in underground coal mines.