Paul Benoit, UMR 8589, LAMOP, University Paris I — CNRS, Jean Féraud History Team, BRGM, Mineral Resources Service, Orléans Françoise Micheau, Professor in Paris I and Director of UMR 8084, medieval Islam: cultural spaces, networks and practices, University Paris IV — University Paris I — CNRS Florian Téreygeol, UMR 5060, IRAMAT, Paléométallurgy and Cultures Laboratory, UTBM, Belfort and LRC DSM 01-27, CEA, Saclay The Yemeni Geograph al-Hamdână writes...