188 Dr. Jack on the Geologic and Topography 



some of the villages or towns are several miles in circumfe- 

 rence. The Siak river, which is navigable for a hundred miles 

 from its mouth, rises in the northern portion of Rana-lima- 

 pulo, and chiefly from the mountain Tinkalang. 



With Menangkabau and the sources of the Indragiri river 

 the journey undertaken in 1818 by Sir T. S. Raffles has made 

 us better acquainted. He proceeded from Padang, on the 

 west coast, and after crossing three ridges of hills, exceeiling 

 4O00 feet in height, and covered with primeval forests, through 

 which the beds of torrents afforded the only passage, he de- 

 scended upon the Tigablas country, which is bounded on the 

 south by Gunong Tallang. The cultivated part of the great 

 valley of Tigablas may be about twenty miles long and ten 

 broad, and would seem to have been at one time entirely co- 

 vered by the waters of the existing lake, which is skirted by 

 hills in every direction, that of the valley excepted. Gunong 

 Tallang, with its adjacent hills, seems to form a transverse 

 range, and to break the regularity of all the other ranges 

 which it intersects. On the eastern side of the lake, which is 

 about fifteen miles long by from seven to nine broad, com- 

 mences the province of Menangkabau Proper, and at the di- 

 stance of a few miles from its banks is situated the ancient ca- 

 pital of Pagaruyong. 



The Indragiri river has its source on the eastern side of Lake 

 Sophia*, and flows through the province of Menangkabau, 

 receiving the waters of the celebrated Ayer Mas or " Golden 

 Stream," which passes through Pagaruyong, and soon after 

 of a large river which rises in Agam, behind G. Singalang and 

 G. Berapi, and traverses a portion of the more eastern district 

 of Rana-lima-pulo. The Indragiri is navigable for small boats 

 a considerable way above the falls ; but the exact position of 

 these has not been ascertained. The mountain of most in- 

 terest in this quarter is that of Berapi, v/hich is constantly 

 emitting smoke : its elevation was ascertained, by angles taken 

 from the lake, to be about 1 3,000 feet : it is connected towards 

 the western coast with the mountain Singalang, estimated at 

 about 12,000 feet; and to the north and eastward with Gu- 

 nong Kasumbra, first discovered on this expedition, and cal- 

 culated to be not less than 15,000 feet above the level of the 

 sea, being therefore the highest mountain in Sumatra. The 

 Kampar, which is mentioned in the Portuguese histories as of 

 some importance, is a river of small size, situated between the 



* The lake, to which the natives had given no proper name, has lately 

 received the denomination of Lake Sophia, in honour of Lady Raffles, 

 who accompanied Sir T. S. Raffles in his late expedition into this part of 

 Sumatra. 



Siak 



