164 AUSTRALASIA. 



natural depression between the two parallel sections of the island to its delta in 

 Surabaya Strait over against the western extremity of Madura. 



At its southern entrance this shallow passage receives another large river, the 

 Brantas or Kediri, which, although ranking next in size to the Solo, is scarcely 

 navigable except during the floods. The Brantas, which also rises very near the 

 Indian Ocean south of the Kawi volcano, is remarkable for the quantity of 

 sediment it washes down, and for the disproportionate size of its constantly 

 increasing delta. 



On the southern slope of the island the chief streams are the Progo, whose 

 farthest waters flow from the Sindoro and Sumbing volcanoes on the west, and 

 Merapi and Merbabu on the east ; the Seraju, fed by numerous tributaries from 

 the Sumbing, Slamat, and other volcanoes, and navigable in its lower course ; 

 lastly, the Tanduwi, whose headstreams descend from the Sawal Mountains, and 

 whose broad estuary is accessible to steamers. In its lower course the Tanduwi 

 winds through a vast marine inlet, which has been transformed to a rawa, or 

 marshy plain, by the alluvial matter washed down with the surrounding torrents. 

 Of the original inlet nothing now remains except the shallow Segara Anakan, 

 which is already nearly cut off from the high sea by the long rocky island of 

 Nusa Kembangan. This island itself, which has greatly contributed to the silting 

 up of the inlet by preventing the sedimentary matter from being carried sea- 

 wards, is now separated from the mainland only by a narrow muddy backwater ; 

 it may already be regarded as forming an integral part of Java, from which it 

 was formerly detached by a broad intervening channel. 



Climate. 



The Javanese climate resembles that of the other western Indonesian lands, 

 offering the same alternation of the two trade winds, which here assume the 

 character of monsoons. Both are accompanied by a certain quantitj^ of moisture, 

 the western being as a rule the more humid and attended by the more stormy 

 weather. Being partly sheltered from the west winds by Sumatra, Java receives 

 less moisture than the uplands of that island. The atmospheric currents are also 

 modified by the disposition of the mountain ranges, running in the direction from 

 west to east. The south-east trade frequently veers round to the south, while the 

 west monsoon is shifted to the north. The northern and southern seaboards thus 

 present a great contrast, due to the direction of these winds, and an analogous 

 contrast is offered by the eastern and western extremities of the island owing to 

 the gradual increase of dryness as we approach the Australian Continent. 



Other differences arise from local conditions, but most moisture falls every- 

 where on the western slopes exposed to the " bad " monsoon. Above 2,600 feet 

 the alternation of land and sea breezes is no longer observed, and at 5,000 feet the 

 west monsoon loses its strength. Still higher up a neutral zone prevails, while 

 the highest summits are subject to the south-east trade alone. Several days 

 seldom pass without rain on the uplands, and almost every evexiing has its local 



