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Trial reconstruction of an early process of iron extraction In KUML 1962 were presented the results of certain new investigations of prehistoric iron extraction plants 1) which have made it possible to put forward a new basis for reconstruction of the plants which were used for iron smelting in the first centuries A. D. It has unfortunately not been possible to demonstrate by excavation every detail in the proposed reconstruction, as, for example the height of the shaft and details in the construction of the connection between the shaft and the slagpit.All the remains of furnaces hitherto investigated have been more or less altered by the actual process of the smelting, and we are therefore without evidence of the appearance of the furnace at the start of the process. Only a fortunate combination of circumstances could allow us to discover such evidence, but it should be possible to gain a degree of knowledge if the smelting process could be successfully imitated in a reconstructed furnace. The chief importance of such successful experiments would, however, be to provide a reliable basis for calculations of production and consumption.Experiments in smelting were begun at Drengsted in the autumn of 1963 by the Aarhus University Institute of Prehistoric Archeology and Ethnography and were later carried further at the Varde Steelworks Limited. The following is an account of the experiments at the latter place.Considerations before the start of the experiments To convert iron ore into iron is a very easy task. All that is needed is a suitable temperature and a suitable reducing agent, that is, a substance which is able to remove the oxygen which is in chemical combination with the iron of the ore. One of these reducing agents is the gas carbon monoxide.The chemical process in the reduction of iron ore may in simplified form be writtenFeO +CO à Fe+ C02.The reaction begins to take place at about 650° C, and speeds up at higher temperatures.Now, as luck will have it, burni