EARTH FISSURKS AND SAND CRATERS. 49 



at a right angle, in the winding- course of which the Barak leaves it ; 

 the banks just at the point of junction are bold and lofty, while in 

 general below the end of the Barak River they are lower, as is also the 

 ground on the east of the curve. Here the left bank of the river had 

 been shaken down, forming an almost precipitous face of more than 

 forty feet in height, while the ground round the curve had also been 

 separated and had slipped into the river in two rather long slices; the 

 strong current sweeping along and against the left bank had, before 

 I reached the place two months after the shock, removed the greater 

 part of the fallen mass, but the portions which had fallen formed two 

 small ridges, a few points of which were still above water, and on which 

 the current was beating-, with channels between. These great masses of 

 fallen matter in the bed of the river had produced strong- eddies and 

 whirling currents, and it was with the greatest difficulty that the boat- 

 men after a good deal of exertion, and only by getting out towing lines, 

 succeeded in passing the boat up in safety. 



Here for the first time the immediate cause of all this ruin became 

 evident. Just at the water-level, and under a thickness of more than 

 40 feet of varying clays and sandy clays, was seen a band of soft 

 and slimy, peaty stuff charged with ferruginous water, which oozed out 

 on the edge of the cliff; this rested on, and was in fact mixed up with, a 

 layer of fine arenaceous sand, which when wet and saturated with this 

 black slimy water is dark coloured and nearly black, but which on 

 drying became of a light blue colour; the whole bed is but little more 

 than 3 feet thick. That the easy and unequal yielding of this soft 

 slimy mass under the pressure of the heavy beds of clay above was 

 really the source of the mischief, was very evident, because under 

 this the recurring stiff clays formed a regular shelf sloping down 

 to the water, but perfectly sound in places where the slips had been 

 developed in the most marked way. In one or two small patches, 

 before going thus far, I had been able to trace the existence of some 

 such bed as this, and in other places the occurrence of a deposit of this 

 light-bluish sand in the cheeks of some of the cracks had led me to 



( 49 ) 



