Henry Cleere conducted four experimental smelts at Horam in July 1969, and the working papers of experiments 2 to 4 have survived. He wrote up the results of the experiments for an article, ‘Ironmaking in a Roman furnace’ published in the journal Britannia, vol. 2 (1971), pp. 203-217. He also drafted an article for Alloys & Metal Review .
Images of the experiments can be seen here:
Experimental smelt 2
Experimental smelt 3
Experimental smelt 4