Iron Age, the last of the three stages, stone, bronze, iron, which mark the prehistoric development of most now civilised peoples; these, of course, occurred at different periods, and were of different duration in different cases; they are named from the material employed in making cutting instruments and weapons; the forms of instruments are freer than in the bronze period, and rectilineal gives places to free curvilineal decoration; this age is marked, too, by the introduction of writing and the beginning of literary and historic records. See Ages.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Irmin * Iron City