Before revision: The first repeatable and reliably successful furnaces and smelts were managed by the same person in both the United Kingdom and the United States, in the principal control and supervision of Ironmaster David Thomaswho had begun experimenting with attempts to use locally available Welsh anthracite deposits as early as 1820 soon after he became in charge at Yniscedewin Iron Works in Wales.
After revision: The first repeatable and reliably successful furnaces and smelts were managed by the same person in both the United Kingdom and the United States, in the principal control and supervision of ironmaster David Thomas, who began experimenting with attempts to use locally available Welsh anthracite deposits as early as 1820 soon after he became in charge at Yniscedewin Iron Works in Wales.