years subsequent to the expedition of Alexander. Concerning the changes which happened during that millennium absolutely nothing is known. But during the twelve hundred years that have elapsed since the Arab conquests changes on a stupendous scale are known to have occurred, and it is certain that similar effects must have been produced by the ever operating causes during the thousand years which intervened between Alexander and Muhammad bin Kasim. During the known period, earthquakes, floods, changes of level, denudation, accretion, and alterations of climate have all contributed to transform the face of the country. The delta of the Indus has advanced more than fifty miles, and has thus lengthened the courses of the rivers, while diminishing their gradients and velocity. One huge river, the Hakra or Wahindah, which formerly gave life and wealth to the desert wastes of Bikanir, Bahawalpur, and Sind, has ceased to exist; the Bias (Hyphasis) has forsaken its ancient independent bed and become a tributary of the Sutlaj; and the other rivers, the Indus, Jihlam (Hydaspes), Chinab (Akesines), and Ravi (Hydraotes), have all repeatedly changed their courses and points of junction.
These facts, although indisputably true, have been ignored generally in practice by the historians of Alexander, who have pretended to trace the line of his river voyage on modern maps, and to "identify" town after town on the banks of the several rivers. All such identifications are vain. No man can tell in which of the ancient beds the Chinab or any of the other rivers
