I 



BY THE REV. J. E. TEN ISON- WOODS. 133 



bottom around the island in the directions of Sumatra and Java, 

 giving depths of 60 and 80 fathoms, where formerly 40 to 50 

 fathoms was the extreme. A mile south of Krakatoa 12G fathoms 

 were obtained, where 80 was the former record. 



Hot Springs. — As might naturally be expected, the hot 

 springs and wells of Java present most interesting phenomena. 

 At Surabaya, in the midst of the alluvial flats, there is a petroleum 

 well which, I think, like many others of its kind, is connected 

 with immense deposits of drift-wood in the mud beneath. The 

 hot springs and mud springs are numerous, but especially worthy 

 of mention are those of CJrobogan, situated about 30 miles east 

 in a straight line from Samarang. They are seldom visited by 

 travellers, but deserve careful investigation. The most convenient 

 way to reach them is to go by railway from Samarang to the 

 Gundik station, from whence there is a fair road due north 15J 

 miles to Purwodadi, one of the important towns of the province 

 of Japara. Five miles more of a carriage road brings one to 

 Grobogan, a village or earn pong to the south of a small east and 

 west limestone range. In the valleys between the spurs from this 

 range on the south side there are many hot springs emitting both 

 mud and steam. About the centre of the range is a mud geyser 

 which in Horsfield's time emitted periodical explosions of mud 

 and steam, but is mnch more intermittent in character now. 

 Horsfield's description is as follows : — 



"About the centre cf this limestone district is found an extraor- 

 dinary volcanic phenomenon. On approaching it from a distance 

 it is first discovered by targe volumes of smoke rising and disap- 

 pearing at intervals of a few seconds, resembling the vapours 

 arising from a violent surf \ while a dull noise is heard like that 

 of distant thunder. Having advanced so near that the vision is 

 no longer impeded by the smoke, a large hemispherical mass is 

 observed, consisting of black earth mixed with water, about 16 

 feet in diameter, rising to the height of 20 or 30 feet, in a per- 

 fectly regular manner and as it were pushed up by force beneath, 

 which suddenly explodes with a dull noise, and scatters about a 



