72 REPORT— 1873. 



To forget, in referring to this subject, the name of our great and veteran leader, 

 Sir Charles Lyell, would be difficult for any who have profited by the perusal of 

 his masterly works, is impossible for those who, like me, have been witnesses of that 

 life-long zeal and energy which carried him to explore distant regions and make 

 fi-iends for English Geology in every quarter of the globe. 



Keeping our attention on Pleistocene Geology, we may remark that the famous 

 cavern of Kirkdale, with the equall}^ celebrated rock den of bears and hyseuas at 

 Torquay, receive no small help toward clearing up the history of mammalia in 

 Britain from the explorations now going on in the limestone cliffs not far from this 

 place of meeting. In Kirkdale Cave no trace of human ai't appeared ; Kent's Hole 

 has given proofs of the presence of man from the earliest period characterized by 

 the remains of the gi-eat bear; and both there and in the Victoria Cave near 

 Settle, at much later periods, domestic occupation is fully established. 



It will be readily conceded that for gathering good information regarding the 

 aborigines of our land the British Association has wisely appropriated some por- 

 tion of its funds ; probably we shall agree in thinking that the additional data 

 which may be expected are worthy of further expenditm'e and the employment of 

 valuable labour. And this leads me to remark how real is the obligation of this 

 Association to some of its members who have directed these researches, and how 

 large a debt of gratitude is due to one in particular, who, not content with tm-uing 

 every day his intelligent eyes on the remarkable phenomena disclosed by excava- 

 tion in the Torquay caverns, has with his own hands cleared and washed thousands 

 of bones and teeth, studied, labelled, and arranged them, and year by year has de- 

 lighted this Section with careful narratives of what he and Mr. Vivian, following 

 the steps of MacEnery, have surely observed and recorded. Labom- of this kind 

 the Association cannot purchase ; nor would the generous spirit of my friend con- 

 sent to such a treaty. I may, however, use the privilege of my temporary office, 

 and suggest to j'ou to consider whether the time is not come for the friends of the 

 Association, and especially the members of this Section, to unite in a general effort, 

 and present to Mr. Pengelly a substantial proof that they highly appreciate his disin- 

 terested labours in their service, and the ample store of new knowledge which he 

 has had so large a shai-e in producing. 



During the long course of geological time the climates of the earth have changed. 

 In many i-egions evidence of such change is furnished by the forms of contemporary 

 life. Wai-m climates have had tlieir influence on the land, and favoured the gi'owth 

 of abundant vegetations as far north as within the arctic circle ; the sea has 

 nourished reef-making corals in Northern Europe during Palaeozoic and Mesozoic 

 ages ; crocodiles and turtles were swimming roimd the coasts of Britain, among 

 islands clothed with Zamia and haunted by marsupial quadrupeds. How have we 

 lost this primpeval warmth ? Does the earth contribute less heat from its interior 

 stores ? does the atmosphere obstruct more of the solar rays or permit more free 

 radiation from the land and sea ? has the sun lost through immensity of time a 

 sensible portion of his beneficent influence ? or, finally, is it only a question of the 

 elevation of mountains, the course of oceanic currents, and the distribution of land 

 and sea? 



The problems thus suggested are not of easy solution, though in each branch of 

 the subject some real progress is made. The globe is slowly changing its dimen- 

 sions by cooling ; thus inequalities and movements of magnitude have arisen and 

 are still in progress on its surface : the effect of internal pressure, when not resulting 

 in mass-movement, is expressed in the molecular action of heat which Mallet applies 

 to the theory of volcanoes. The sun has no recuperative auxiliary known to 

 Thomson for replacing his decaying radiation ; the earth, under his influence, as 

 was shown by Herschel and Adhemar, is subject to periods of greater and less 

 warmth, alternatelj' in the two hemispheres and generally over the whole surface ; 

 and finally, as Hopkins has shown, by change of local physical conditions the 

 climate of northern zones might be greatly cooled in some regions and greatly 

 warmed in others. 



One is almost frozen to silence in presence of the vast sheets of ice which some of 

 my fr'ends (followers of Agassiz) believe themselves to have traced over the moun- 

 tains and A ales of a great part of the United Kingdom, as well as over the kindred 



