A GENERAL SKETCH OF SUMATRA: 
348 
principal inhabitants of the island whether we consider their 
range, numbers, actual territory, influence or civilization. 
They entirely occupy the widest and middle region of Sumatra 
extending from the Rakan nearly to the P&lembang on the 
east coast, and from Ayer Baugis to Kataun on the west coast, 
a length of about 275 m. with an average breadth of about 190 
m. and a superficies of 52,250 square miles, or little short of 
one half of Sumatra. The east coast is nearly straight, 
running throughout in a direction due N. W. by N , and 
evincing the wonderful regularity, unity and power of the 
elevatory movement which formed the mountains. The 
breadth of the highlands is about 95 miles. The low land 
that stretches from their base to the east coast has about 
the same average breadth, so that the region is divided in 
nearly equal proportions between them. The greater 
part of the lowlands appears to be nothing more than the 
waste matter of the mountains brought down by the 
streams, and as the ranges must have been pared down 
to a still greater proportionate extent on the western side 
of the watershed, where their sea face is exposed to a tre¬ 
mendous surf, the loss must have been enormous, and the 
date of their elevation extremely remote. It is this accu¬ 
mulation of sediment over so wide a surface on the east 
side of the mountains that has given rise to the great rivers 
which intersect the plain, the Siak, Kampar, Indragiri, 
Jambi and Palembang. It was the possession of this central, 
largest and most highly favoured region, that enabled the 
Malays to grow in numbers and civilization till they ob¬ 
tained supremacy in Sumatra, The mountains contain 
numerous vallies, some of great extent, all well watered and 
many enriched by volcanic soil. The population varies 
extremely in density. The higher parts of the mountains, 
and the low land between the rivers, are left to the jungle 
and wild animals, and possess hardly any human inhabitants. 
The rivers have considerable collections of houses scattered 
at greater or less intervals along their banks, and extending 
a short distance from them. The principal vallies in the 
mountains, on the other hand, are completely cultivated and 
filled with inhabitants. While the countries of Siak, Indragiri, 
Jambi and the northern part of Palembang, including a por¬ 
tion about 25 miles broad of the eastern flanks of the moun¬ 
tain land, contain about 200,000 souls or 5 to the square mile, 
the single province of Menangkabau has a population of about 
385,000 or 128 to the square mile, and the whole mountain 
land taken together gives a mean of 40 to the square mile. 
