Note 580 — Chapter VIII

Too much stress must not, however, be laid upon the theory of gradual desiccation as a factor in depopulation. There are many causes such as earthquake, water-spouts, shifting of currents, neglect of irrigation and, above all, the work of enemies to account for the sand-buried ruins of populous cities in Central Asia. See T. Peisker, "The Asiatic Background," Cambridge Medieval History, Vol. I. 1911, p. 326.