That one is afforded by the narrow valley of the Hari Rud to the west of Herat.
South of the Middengebergte, however, the northern affluents of the Batang Hari, the Seliti, Gumanti, Si Potar, Mamun and Pangean, at least those in the west, again run in longitudinal valleys.
These affluents and the Batang Hari itself (except the part at the mouth, Mamun-Simalidu) are navigable only by praus drawing not more than in.
By military expeditions (1890-95) the Dutch influence on the Batang Hari, or Upper Jambi, was increased; as also in 1899 in the Lima Kotas 1 in central Sumatra, included within the territory of Siak.
It is the startling contrast of the Herati oasis with the vast expanse of comparative sterility that encloses it which has given such a fictitious value to the estimates of the material wealth of the valley of the Hari Rud.
