The note suggests that the technique of estimating age by counting of fission tracks in slag could possibly be used in the study of ancient iron produced by the bloomery process. Counts could be made on furnacebottoms which could then provide C₁₄ age-estimations from the entrapped charcoal which these usually contain. These results could then be used to calibrate those produced by counts from slag particles found during metallographic examination of bloomery iron. -- AATA