JAVA. 151 



been to a great extent filled in by outflows of lavas and showers of ashes and scoriae. 

 Eastwards the island falls gradually nearly to the level of the sea ; but towards the 

 extreme east the mountains again rise with a uniform slope from base to summit. 

 The volcanoes, which follow from one end of the island to the other, are not 

 develoj)ed in a continuous chain, and in many places are separated one from the 

 other by a distance of 30 miles. 



But it is noteworthy that they are often grouped two, three, or four together, 

 forming independent ridges, whose axes run, not parallel with, but obliquely 

 athwart the main axis of the island. They are in fact disposed mainly in the 

 direction of the axis of Sumatra, while by a remarkable contrast those of Sumatra 

 itself run parallel with Java. Thus the crevasses through which the lavas were 

 ejected appear to have been caused in both islands as it were by a sort of inter- 

 change of the igneous forces. The underground energies are also about balanced, 

 for the Javanese Semeru is only a few feet lower than Indrapura and Korinchi, the 

 highest volcanoes in the neighbouring region. Altogether the mountains of Java 

 are not inferior in mean altitude to those of Sumatra, while the absence of subja- 

 cent terraces gives them a greater relative elevation above their base. 



Java also differs from Sumatra in the rarity of longitudinal valleys between 

 the parallel crests and in the absence of lacustrine basins. The mean altitude of 

 the whole island is estimated by Junghuhn at somewhat less than 1,650 feet. 



Of the volcanoes, two near the north coast, Karang at the north-west corner, 

 and Murio (Murya) in the peninsula east of Semarang Bay, appear to belong 

 to an independent igneous system. Both occupy isolated positions on the plains, 

 so that a rise in the former case of 1,000, in the latter of 15 or 16 feet above the 

 present sea-level, would suffice to convert them into islands. They are still sur- 

 rounded by alluvial deposits which rest against the northern flanks of hills belong- 

 ing to the tertiary age and disposed parallel with the main Javanese axis. In the 

 same way the volcanoes on the opposite side skirt the northern base of other 

 tertiary heights which run in a line with the south coast. Java in fact, according 

 to Junghuhn, consists of two islands merged in one ; but the southern alone is 

 intact, of the northern nothing remaining except fragments. It has disappeared 

 between the provinces of Cheribon and Yapara, where the seaboard develops a 

 large marine gulf, and beyond which Madura is separated by a strait from the 

 Javanese plains. 



Nevertheless, the original coastline may still be recognised, being continued 

 eastwards by a series of small groups comprising the Sapudi, Kangean, and Pater- 

 noster archipelagoes. Southwards is developed, like a vast breakwater, the parallel 

 chain of large islands from Bali to Nila, forming an eastern extension of the main 

 Javanese volcanic range. The terminal points of the disruptured northern island 

 would appear to be Krakatau in the west, and in the east Gunung Api, or " Moun- 

 tain of Fire," north of Wetter Island. 



Both Karang and Murio appear to be at present in a state of repose, the former 

 alone with the twin Pulasari cone emitting some sulphurous vapours. But in the 

 southern chain, Salak, highest of the first volcanic group going eastwards (7,300 



