336 



PUMICE PEBBLES. 



dance of pumice pebbles. I have myself observed 

 these at Wollongong, fifty miles south of Port Jack- 

 son, and at Wallis Islands, in Endeavour Strait, 

 and many intermediate points. They have been 

 noticed by the Rev. W\ B. Clarke and the Rev. N. 

 P. Wilton at several places in New South Wales. 

 They are usually quite rounded, and about the size 

 of walnuts, and at the two extreme points at which 

 I saw them 1 could perceive no difference in their 

 appearance or condition. They occur, then, under 

 precisely similar circumstances, along the eastern 

 coast of Australia for 2,000 miles. They are never 

 or very rarely seen on the present beach,* or recently 

 washed up, nor are they found now T floating at sea. 

 By whatever cause they were cast upon the land, 

 their present position proves that the whole coast 

 where they are found has been equally stationary, 

 or equally affected by movements of elevation or de- 

 pression since they were so cast. I cannot conceive 

 any cause, such as a sudden wave in the sea, that 

 can have cast them to a greater height above its 

 general level than that at which they are now found. 

 Near Wollongong, and in other parts of New South 

 AVales, there are clear proofs (in raised beaches, 

 &c.) of elevation of the land having taken place in 

 comparatively recent time, whether previously to, 



* In the few cases where they have heen found lying on the 

 present beach, there were circumstances sufficient to show that 

 they had not been recently washed up hut down, out of the sands, 

 or off the flats behind the beach. 



