ABSTRACT
The old bloomery process would only work with charcoal; when charcoal became expensive it was natural to look for a process which would use the more widely available fuel – coal. Both the finery slags and the hammer scale can be returned to the blast furnace where convenient. The iron ores were mainly of the carbonate type as may seen from table 105, be and for the easiest smelting needed roasting. The metal to be heated was inserted into the hollow where it was heated by radiation. The blast furnace was introduced from abroad because it had evolved from a type of bloomery furnace which had not been used in Britain since the Roman period. The conversion forges were also heavy users of fuel, but it is more likely that the shortage of water led to their eventual removal elsewhere.
