162 DELTA OF THE KED1RI. 



flowing through the previously or simultaneously- 

 formed volcanic district of Malang and Antang 

 and Japan, began to pour its muddy waters ; that 

 the finer sediment of these flowed far out, making 

 shoaler all the neighbouring sea, and making a 

 base of more than 200 feet at least in thickness, on 

 which coarser and coarser matters were piled as the 

 delta of the river advanced, and that this process 

 went on till many of the smaller islands were ab- 

 sorbed in the growing delta, and connected by its 

 marshes. Some slight elevation might, and proba- 

 bly did, also take place, as the slope of the Kediri 

 through the delta is now considerable, and its 

 current strong ; neither does the tide affect it far 

 up from its mouth, and Madjoago, apparently on a 

 dead level from the sea, is really about 100 feet 

 above it. Still, even independently of any move- 

 ment of elevation, the increase of the delta is going 

 on, and the strait of Madura getting daily shal- 

 lower, and if it had not been for the tide which 

 sweeps through it, long ago it would have been 

 converted into marshes. This tide has carried out 

 from either end of the strait great quantities of 

 detritus, and strewed it over the neighbouring seas, 

 till they are now likewise filling up. The result 

 will be, I believe, the formation of a bar at each 

 end of the strait, obstructing and gradually prohi- 

 biting the entrance and exit of the tide. If this be 

 not artificially removed, a mere pool will at last be 



