The second stage of our experiment involved building of the furnace for which clay containing chamotte ideal for stoneware was utilised. Straw was added to the clay paste and kneaded together in order to increase its refractory capacity. Initially a square pit (40 x40 cm) was dug to a depth of 10 cm and was then lined with clay. The superstructure was built out of small bricks of the clay paste and was raised at a height of 15 cm with a wall thickness of 7 cm. A hole was left at the back side to allow for the tuyère insertion at a later stage. From this point upwards the chimney was raised with a wall thickness of 4 cm leading to a total furnace height of 40 cm. The frontal side was left open and a door was built out of the same clay paste that was attached during the smelt. The furnace was then left to dry for two weeks and one day before the experimental smelting it was pre-fired with wood as a fuel for two hours.
The last stage was that of smelting the iron ore. After a second two-hours preheating stage the smelting started. Air was supplied by an electric blowing device that was used to imitate the hand driven bellows of an ancient metallurgist. It was connected to the furnace via a long tuyère and operated at a low wind speed of 4 in the Beaufort scale. Every ten minutes 1 kg of ore was added followed by 3 kg of charcoal filling up the furnace to its rim. This process was repeated until all the ore was added for a duration of 5 hours. Temperature readings were taken every 20 minutes using a Type K thermocouple allowing us to have the profile of temperature fluctuations during the smelt.
Once the smelt was over the frontal door was opened and the product, that is the iron bloom encased in slag was removed. The upcoming analysis of the bloom and slags will throw light on the efficiency of this simulation and will provide excellent reference material to compare with ancient metallurgical residues that are under study in the framework of project ME.Tech.NAS.
Overall, it was a successful attempt that attracted the attention of local archaeologists and scientists promoting a fruitful discussion on the practicalities and difficulties associated to producing metals in antiquity while stressing the ingenuity of ancient craftsmen. At the same time the educational value of such an attempt has been acknowledged and has paved the way for future collaboration with R.C. ‘Athena’ on similar attempts open to schools’ visits and performances to wider audiences.
Our experimental simulation featured on the local news. In particular it was presented to a daily emission of the radio station of Komotini (ERT Komotinis) broadcasting nationally across Greece. An article was published in the daily newspaper of Xanthi 'Empros'. You can find the relevant articles at the following links: