At the excavation of the settlement Biskupin in Poland, dating from the early Middle Ages, pits could be traced which had been used for the production of birch-tar. The reconstruction of pitch ovens was attempted. Pitch and tar were used for the greasing of wheel hubs and wooden wagon axles, for preservation and caulking, for the impregnation of clothing and leather, for protection against vermin and water, and for therapeutic and occult purposes. R. -D.B. -- AATA