174 COMPENDIUM OF GEOGRAPHY AND TRAVEL 



great depth. At various points round the margin hot 

 springs of 127° Fahr. bubble up, and warm the western 

 end some 10° higher than the temperature of the air. 

 It is abundantly stocked with fish and bivalve mollusca, 

 but when they approach too near the warmer shore the 

 temperature instantly proves fatal to them.-^ This lake 

 is widely celebrated throughout the Western Archipelago 

 for- the tobacco grown upon its shores. The finest quality 

 is made only from the topmost leaves, and commands a 

 very high price. Two or three other mountain lakes 

 occur in the Battak country, but little is known of them, 

 and there are probably others in Ache. Of lowland 

 lakes and swamps there are many in the neighbourhood 

 of the great rivers. 



From the orography of the island it is evident that 

 there can be no rivers of any length on the western side 

 of the main range of mountains. Upon the other side, 

 however, we find the alluvial plain intersected by streams 

 of great size and depth, by which the whole interior of 

 the country is rendered accessible to commerce. Owing 

 to the great rainfall and the steepness of the Barisan 

 chain the erosion which takes place is excessive, and the 

 rivers bear down enormous quantities of debris which 

 deposits around their mouths, blocking the channels and 

 adding to the numerous islands and sandbanks by which 

 they are beset. The change thus effected in the physical 

 condition of the island is enormous. The rapid gaining 

 of the east coast upon the Straits of Malacca has already 

 been mentioned. It is said that at the time of the 

 founding of Palembang the town was situated at the 

 mouth of the river, from which it is now distant some 

 40 miles as the crow flies. Yet for the most part the 

 rivers are not only of great size, but of considerable depth, 



1 A Naturalist's Wanderings in the Eastern Archipelago, H. O. Forbes. 



