SXJMATEA 
173 
To the great alluvial plain which occupies the entire 
eastern portion of Sumatra allusion has already been 
made. It is about 700 miles in length, and from 5 0 to 
200 in breadth, and in area is equal to England. It is 
intersected with large and navigable rivers, by means of 
which trade is carried on almost to the opposite shores 
of the island. Much of it is flooded in the rainy season, 
and, with the rare exception of a few cultivated patches 
on the river banks, it is covered with a stupendous forest, 
coeval probably with the formation of the land itself. 
The greater part of this vast territory is of ample fertility, 
and suited to the growth of most of the products of 
tropical countries, but much of it is in the hands of rude 
tribes who are quite unable effectually to cultivate it. 
Like Luzon, the great island of the Philippines, 
Sumatra abounds in lakes. But while in the former 
these are for the most part either inlets of the sea shut 
off by upheaval or by volcanic ejecta, or the temporary 
sheets of water occurring during the rainy season and 
known as Pinags, those of Sumatra are chiefly mountain 
lakes, many of which occupy the craters of extinct 
volcanoes. The largest of them is the Toba Lake in the 
Battak country (see p. 159), and although no others 
approach its area of nearly 500 square miles, there are 
several of considerable size. Lakes Singkara and Maninju, 
near Padang, are each about 12 or 13 miles in length 
by 3 or 4 in breadth. The latter is fed by thermal 
springs which are much used for their curative powers 
by the natives. The Danau or Kanau Lake (Danau 
signifying lake in the Malay and other allied languages) 
is of similar nature. It was visited in 1881 by Mr. 
H. O. Forbes, who describes it as appearing to occupy 
the site of an old crater at the foot of the Siminung 
volcano. It is about 12 miles in length, and is of very 
