Ball — On Some Effects Produced hy Landslips. 5 



finer materials, have been carried down the slopes of mountains, 

 and spread far and wide in the valleys at their bases. These 

 examples have, however, been fully described elsewhere, so that 

 we may, without more explicit reference to them, pass to the 

 consideration of another variety of soil-cap movements. 



Submerged Forests. 



To by far the majority of people the appearance of submerged 

 forests or bogs in the vicinity of the coast of any land, whether 

 continental or insular, would be accepted, without hesitation, as 

 being indicative of subsidence. Some observers would probably 

 be tempted, moreover, to calculate the amount of the lowering 

 from the data so afforded. My present object is to discuss the 

 reasons which have led me to adopt the view that such a conclu- 

 sion may be wholly erroneous. Nay more, in certain cases, the 

 existence of such submerged forests may even afford prima facie 

 evidence of upheaval of the land. 



I was first led to the consideration of this subject by the 

 existence of apparently very contradictory evidence as to the 

 alteration of levels of sea and land in the case of the Andaman 

 Islands in the Bay of Bengal. 



When visiting the Andaman Islands in the year 1868, the 

 evidence appeared to me to favour the view that the islands were 

 slowly rising. Although there were no raised coral reefs then 

 known in the islands of this group, there were several creeks 

 between the islands which had become more or less unsuitable for 

 navigation. Thus the channel between the middle and southern 

 islands is said to h-^-ve been formerly navigable by large boats, 

 though now, I believe, small boats can only go through it. Again, 

 at the head of Port Blair there is a swampy pass containing man- 

 groves through the hilly grounds to the opposite coast, which 

 presents the appearance of having, at no very distant period, been 

 a strait, dividing the South Andaman into two portions. In the 

 more southern, but next adjoining group of islands, the Nicobars, 

 raised coral reefs are of common occurrence, and their absence 

 in the Andamans is certainly remarkable, and not easily to be 

 accounted for if the view that the islands have risen be correct. 



The late Mr. S. Kurz contended — from the existence of sub- 

 merged portions of forests, and even of buildings which were 



