Those of the eastern slope, on the other hand, such as the Musi, Jambi, Indragiri, Kampar, Siak, Rokan, Panei, Bila and Asahan, are longer, and with many of their affluents are navigable in their middle and lower courses over considerable stretches for craft drawing 6 to 10 ft.
The Musi and Jambi are navigable for 372 and 497 m.
Such are the valley of Korinchi, with the river of the same name, between the peak of Korinchi and Mt Raja; the valleys of Serampei and Sungei Tenang (as imperfectly known as that of the Korinchi), in which are to be sought the sources of the Tambesi and Asei, both affluents of the Jambi; the longitudinal valley of Kedah K i?
Between the mainland dependency of the RiouwLingga residency and the residency of Palembang lies Jambi, an extensive sultanate, of which a portion belongs to the residency of Palembang as a protectorate, the sultan having in his capital (also called Jambi) a Dutch " comptroller," who represents the resident of Palembang; another portion is claimed by a quasi-independent sultan who reigns in the interior.
Of this interior very little was known until the scientific expedition despatched by the Dutch Royal Geographical Society towards the end of the 'seventies, but in 1901 an armed Dutch expedition, necessitated by frequent disturbances, penetrated right into the Jambi hinterland, the Gajo districts, where until then no European had ever trod.
There are ruins of Hindu temples at Butar in Deli, near Pertibi, on the Panbi river at Jambi, in the interior of Palembang above Lahat, and in numerous other localities.
At a later period the Hindu influence in Sumatra was strengthened by an influx of Hindus from Java, who settled in Palembang, Jambi and Indragiri, but their attachment to Sivaism prevented them from coalescing with their Buddhist brethren in the north.
In 1858 an expedition was sent against Jambi; the sultan was dethroned and a treaty made with his successor.
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.