190 Dr. Jack on the Geology and Topography 



The countries of Limun and Batang Assii, through which 

 the two southernmost branches of this river pass, abound in 

 gold, which has latterly been chiefly exported to Moco Moco, 

 Bencoolen, and Palembang. 



At Bencoolen the line of hills is situated about twenty miles 

 inland ; and the space between them and the sea exhibits a 

 succession of riclges and ravines, whose general direction is 

 parallel to the coast, though frequently altered and broken by 

 the irregular working of springs and streams. The hills are 

 principally of the trap formation, and exhibit several varieties 

 of basalt, whinstone, and much of the same gray amygdaloidal 

 trap observed in the neighbourhood of Padang. The most 

 remarkable hill in this quarter is detached from the Barrier 

 range, and is called Gunong Bungko, or by Europeans the 

 Sugar-loaf 1 had lately an opportunity of ascending it, and 

 found it composed almost entirely of irregular masses of basalt 

 or trap, whose bare sui'faces are frequently exj)osed, rising 

 from amid the luxuriant vegetation of the declivities. It had 

 not previously been explored, the shape of the hill rendering 

 the ascent extremely difficult. Its elevation is less than tOOO 

 feet; yet towards the top the trees became stunted, the rocks 

 were clothed with dense moss, and the vegetation assumed a 

 character decidedly Alpine. In the beds of some of the rivers 

 near Bencoolen, particularly that of Silebar, are found pebbles 

 of jasper and chalcedony, with nodules of indurated clay. Iron 

 ores occur not unfrequentlj', and in one part of the Bencoolen 

 river a bed of coal is laid bare by the stream. Very fine spe- 

 cimens of siliceous petrified wood have also been found in the 

 hills of the interior. 



It was not till 1818 that a journey was accomplished across 

 the island of Sumatra in any part. In that year a party pro- 

 ceeded from Bencoolen to Palembang; and the facilities of 

 communication are now found to be such that, did not politi- 

 cal obstacles intervene, it would no doubt soon become a fre- 

 quent channel of intercourse between Bencoolen and the more 

 eastern parts of the Archipelago. 



The Pasummah country, which was first visited by Sir 

 T. S. Raffles in 1818, is an extensive plain of remarkable fer- 

 tility, considerably elevated above the sea, as may be inferred 

 from the temperature, the thermometer being usually as low as 

 65° at 10 A.M. From this plain rises Gunong Dempo, which 

 towers above all the mountains of this part of Sumatra, and is 

 estimated to be no less than 12,000 feet above the level of the 

 sea. It is almost constantly emitting smoke ; and hot springs 

 and other volcanic phsenomena are common in its neighbour- 

 hood. It has been ascended since Sir T. S. Raffles's visit ; 



vegetation 



