ANNIVERSARY ADDRESS OF THE PRESIDENT. liii 



to. I am glad of this opportunity of doing justice to Mr. Martin's 

 claims as an original and accurate observer of many of the geological 

 phaenomena of this district. 



Mr. Martin's theoretical views respecting the denudation of the 

 Wealden, are much more in accordance with those which were more 

 prevalent some years ago than at the present time. He considers it to 

 have been effected by the transporting power of a limited number of 

 large waves, such as have been termed of late waves of translation, or 

 waves of elevation, and not by the more tranquil and long-continued 

 diurnal action of the sea. I confess myself to have no faith in either 

 of these extreme theories, one of which would regard the denudation 

 as almo&t entirely due to tumultuary action, and the other as pro- 

 duced almost solely by the ordinary present action of the sea. If 

 the denudation was tumultuary, the simultaneous deposition of the 

 transported mass must have also been tumultuary. But no tumul- 

 tuary deposit equal in amount to a thousandth part of the mass, pro- 

 bably transported from this and the surrounding districts, now exists 

 in their vicinity. If it ever did exist, how, it may be asked, has it 

 disappeared except by that slow process of denudation which must 

 synchronize with the equally slow process of deposition of sedimen- 

 tary, stratified and fossiliferous beds ; and if this latter process 

 could be thus effective in again transporting the mass after its first 

 tumultuary removal, why should it not have been effective in trans- 

 porting a large portion of this mass from its orighial site ? But, again, 

 on the other hand, are we to assume that there has been no tumul- 

 tuary action peculiar to periods of great disturbance and denudation ? 

 A few years ago only geologists were doubting whether the Drift in 

 general was subaqueous or subaerial ; but no one now doubts its being 

 the former, and, that doubt being removed, I contend that the proof 

 of tumultuary action afforded by what are considered drifted mate- 

 rials, is as conclusive as that of more tranquil action afforded by the 

 fossiliferous beds of former periods. In fact it is by the character 

 of the transported masses alone that we can judge of the energy of 

 the agency which has removed them. To do otherwise must be to 

 depart from the true spirit of inductive philosophy, and to base our 

 theories upon unsupported hypotheses. 



In the region of the Wealden we have little direct evidence of any 

 action of violent intensity in the process by which it has been de- 

 nuded. At the same time we have, as Sir R. Murchison has con- 

 tended, distinct evidence in the characters of the superficial drift, of 

 an action different from the daily action of the sea, and to a certain 

 extent tumultuary. Had the process of denudation been continued, 

 this coarser matter would doubtless in its turn have been comminuted 

 and carried off possibly in the form of fine sediment. And further, 

 if this more powerful action was produced in the last period of the 

 denudation, how can we avoid the conclusion that a similar action 

 must have been frequently repeated during the period in which all 

 the principal phsenomena of elevation throughout the district must 

 have been produced ? The conclusion appears to me inevitable. I 

 conceive that by a repetition of such action, not necessarily of any 



