284 THE BASIN OF EASTERN PERSIA AND SISTAN. 
trough — ^at least 100 miles in length by 30 in width — which appears to have received 
either the whole of the present water-supply [of Sistan] or the overflow of the old 
and greater flood ; otherwise it is impossible to account for its vast area. The Shila 
runs ill a briny stream when there is a large accession to the lake." Yate, writing 
of a journey made about 1894, speaks of the Shila (p. 98) as being from 150 to 200 
yards wide, with precipitous banks 30 to 40 feet high, where he first .saw it. There 
was no sign of a running stream, but merely pools of bitterly salt water. Thirty 
miles farther downstream he found (a, p. 99) the Shila " 150 yards in width, with 
sloping banks some 20 feet high and full of sand, there having been no flood-waters 
down for the last five years." Below this point fp. 102) the banks of the Shila 
gradually decrease in height and finally die out on approaching the God-i-Zirrah. 
From these two descriptions the outlet appears to be through a broad, deep channel, 
which could only be cut by a strong, vigorous stream far different from the trickling 
overfow of the rare floods which now traverse it. Smith, however (a, p. 254), 
describes the Shila in very different terms as "a low, shallow sort of ditch or canal, 
about thirty yards wide, and quite dry." As he crossed the channel near the places 
seen by Sykes and Yate, there .seems to. be no way to reconcile the opposing 
statements e.xcept by supposing that the outlet, like the tributaries, is terraced, and 
preserves the record of two periods of overflow corresponding to the two elevated 
shorelines which will presently be described. 
The lowest portion of the basin of Sistan and the final resting-place of the 
waters which escape via the Shila is the God-i-Zirrah, or Hollow of Zirrah. McMahon 
(a, p. 19) describes it as "a large lake of clear, deep-blue water, some 25 miles long 
and 5 miles wide, standing in the midst of a wide margin of solid salt. It used to 
be fed by flood-water from the Hehnund, but it now seldom receives any replenish- 
ment. The last time it received any water from the Hehnund is, .so far as I can 
ascertain, as long ago as 1880, i.e., .seventeen years ago. [Yate, p. 105, says 1885.] 
All the drainage which, in tlie natural course of events, should flow into it from the 
mountain ranges south of it is intercepted and swallowed up by the wide barriers of 
sand lying in the way and thus never reaches it. Its water is now so salt that even 
water-fowl avoid it." 
A glance at the map shows that the Shila and the God-i-Zirrah form an arc 
parallel to the arc of the Hehnund and sloping in the opjiosite direction. In ancient 
times, according to Ishtakhri, who wrote in the tenth centur)^ (quoted by Sykes, 
rt, p. 365), the Hehnund was diverted so as to flow across the neck between the two 
arcs and discharged directly into the Shila. The lake of Zirrah was 100 miles 
long and covered an area ten times as great as to-day. It was filled to overflowing, 
apparently, and the direction of the Shila was reversed, for the people of Sistan 
have a legend that in former times the supply of the Hamun-i-.Sistan entered at the 
southern end of the lake instead of the northern. Part of the water of the Hehnund, 
however, still flowed to Sistan along the present course and watered the numerous 
villages the ruins of which crowd the upper part of the Hehnund delta. In course 
of time this main channel regained all the water, perhaps, as McMahon (a, p. 20) 
suggests, because the Hehnund deepened its bed below the mouth of the canal which 
leads to the Shila. To-day that canal still exists, and until a hundred years ago 
