224 COMPENDIUM OF GEOGEAPHY AND TEAVEL 



that it is often possible to pass from one river-basin to 

 another without any great ascent, and this arrangement 

 of the mountains may be regarded as a characteristic 

 feature of the orography of the island. 



Borneo is remarkable both for its plains and rivers. 

 The southern and eastern portions of the island are, in 

 the main, areas of flatness and little elevation, as may be 

 gathered from a glance at the map, which shows the 

 rivers to be of almost phenomenal tortuousuess. In some 

 places quite flat, in others gently undulating, these plains 

 occupy the spot where, in pre-Tertiary days, the sea 

 flowed. Towards the coast, and in the vicinity of rivers, 

 this flat land often exists as vast and impassable 

 morasses, wdiich in the wet season become much en- 

 larged, so that enormous areas become submerged. 

 Schwaner estimated that 160 square geographical miles 

 are daily flooded by tidal action in the basin of the 

 Barito, and 580 — or more than one-third of the entire 

 basin — in the rainy season. Like phenomena may be 

 witnessed upon many, if not most, other of these rivers, 

 and Dr. Posewitz, in his work on the geology of the 

 island, gives the following graphic description of the 

 appearance of the district surrounding the Negara, an 

 afliuent of the Barito. " During my first journey every- 

 thing, as far as the eye could see, was covered with water : 

 it appeared to extend to the mountain-chain skirting the 

 eastern horizon, the foot of which is surrounded by steep 

 Tertiary coral reefs. In the midst of the flooded district 

 one could see ISTegara, an important seat of industry, extend- 

 ing along the end of the great sheet of water, as if it were 

 situated on an inland sea. In the swampy parts there 

 were thick patches of rushes, which formed welcome 

 resting-places for dense swarms of mosquitoes, and the 

 oarsman in threading his way is obliged to keep a sharp 



