CLIMATE AND HISTORY. 303
after mile was carefully terraced, while here and there were mounds littered with pottery. War, no doubt, has had much to do with it, but even more probably ruthless deforestation in this and adjacent districts had decreased the rainfall, after which the springs dried tip and the population was driven away."
Holdich, speaking of the swamp of Mashkel, which lies in the same part of Baluchistan, but a hundred miles nearer to Sistan, remarks :
This extraordinary abundance of water locally is difficult to explain. It appears to be a survival of a far more extended condition of water-,supply in southern Baluchistan than now exists. There is widespread evidence of 'former cultivation by an elaborate system of irrigation in so many parts of southern Baluchistan, where it is vain to hope that such cultivation will ever exist again, that it seems as if sonic mighty change must have come over the land thus to render so much of it waterless. It may be due to forest denudation and cessation of rainfall, 'but, more 'likely, it is due to the gradual exhaustion of those subterranean sources which seem to be still prevalent in more northern districts.
In speaking of the mountains of Kharan, too or zoo miles east of Mashkel, in the center of northern Baluchistan, Vredenburg (p.213) comes to a similar conclusion :
In all the valleys round Zara there are to be seen 'hundreds of stone walls which are called "gorband," or "dams of the infidels." Sometimes they stretch tight across the flat, pebbly floors of the groat valleys, which, for want of a better name, are 'termed " rivers." They also occur across the entrance to most of the tributary ravines and at various heights above the main valley. The country is quite uninhabitable for want of water, and yet there is no doubt about the nature of these walls, which are similar to works erected to the present day in many regions of Baluchistan and Persia, 'being, in fact, nothing 'but terraced fields. In many cases they still hold iback the soil, formerly cultivated, 'which has been heaped up against them. . . . The absence of any canals, the greatheight to which the walls are found up the tributary ravines, show that the fields were not watered by means of some general scheme of irrigation with canals deriving their supply from some reservoirs placed at a greater altitude. Perennial springs, now everywhere dried up, must have existed in all the ravines where these remains are found, which shows how much greater the rainfall must have been formerly.
From the evidence of certain tombs Vredenburg thinks that the fields were in use even down to Mohammedan times.
The march of Alexander from Mesopotamia across Persia to Samarkand and the Jaxartes River, and thence via Bactria to India and back through Baluchistan to Persepolis and Babylon, is justly regarded as one of the most remarkable feats in history. There have been innumerable discussions of the subject, and the general tendency, especially of those writers who have actually traversed the more remote routes followed by the conquerer, is to think that under present conditions the march would have been impossible. This is not the place to discuss the whole question, but a few remarks upon the portion of the journey nearest Sistan may not be out of place. When Alexander left India he divided his army of to,000 men into two parts, one of which, including the elephants, the invalids, and the heavy baggage, was put under the command of Krateros, and followed a route through southern Afghanistan and Sistan. Alexander himself, as Sykes says (p. 169), "faced the horrors of the desert by the route along the coast of Baluchistan in order to supply his fleet by means of his army," although Arrian says it was because of his wish to rival the journeys of Semiramis and Cyrus along the same road to India.