I GEOGRAPHY OF BORNEO 5 



highest reading of one year {1906) at Kuching was 

 94°, the lowest 69°. Snow and frost are unknown, 

 except occasionally on the summits of the highest 

 mountains. Thunder - storms are frequent and 

 severe, but wind -storms are not commonly of any 

 great violence. 



The abundant rainfall maintains a copious flow 

 of water down the many rivers at all times of the 

 year ; but the rivers are liable to rise rapidly many 

 feet above their normal level during days of ex- 

 ceptionally heavy rain. In their lower reaches, 

 where they traverse the alluvial plains and swamps, 

 the rivers wind slowly to the sea with many great 

 bends, and all the larger ones are navigable by 

 small steamers for many miles above their mouths : 

 thus a large steam launch can ascend the Rejang 

 for 160 miles, the Baram for 120, and some of 

 the rivers on the Dutch side for still greater 

 distances. The limit of such navigation is set 

 by beds of rock over which the rivers run shallow, 

 and which mark the beginnings of the middle 

 reaches. In these middle reaches, where the rivers 

 wind between the feet of the hills, long stretches 

 of deep smooth water alternate with others in 

 which the water runs with greater violence between 

 confining walls of rock, or spreads out in wide 

 rapids over stony bottoms. The upper reaches of 

 the rivers, where they descend rapidly from the 

 slopes of the mountains, are composed of long series 

 of shallow rapids and low waterfalls, alternating 

 at short intervals with still pools and calm shallows, 

 bounded by rock walls and great beds of water- 

 worn stones, which during the frequent freshets 

 are submerged by a boiling flood. The whole 

 river in these upper reaches is for the most part 

 roofed in by the overarching forest. 



Practically the whole of Borneo, from the sea- 

 coast to the summits of the highest mountains, is 



