HISTORICAL XOTICKS. .» 



reaction to iK'tlcr xicws luis hcL^iiii to set in, and that 

 <fo.olo^yists ai'(; nion; (lisposod than formerly to restrict 

 tlu'ir s])('culations within the limits of physieul possihility. 

 AVc shall sec cvidiuici! of this in tlu; s('(|n('l ; hut hcfore 

 referring to the conclnsions of others, I nniy he jiurdo.ied 

 for j^'ivin*^ a sKetcli of the ])ro,L!;ress of ojiinion, as it has 

 presented itself in connection with my own work. 



When I first luitered on the stndy of these depcjsits in 

 Nova Scotia, in the year 1841 and snl)se(|nent yeai-s, my 

 <i;uide and instructor was the great a])ostle of moderate 

 uniformitarianism, that is, of rational geology. Sir Charles 

 I.yell. His \iews as to th(i comhiiied agc^ncy of land ice 

 or glaciers, of floating fragments of glaciers or ice-hergs, 

 and of field ice, are, or ought to be, well known; hut I 

 nmst say that they have fiften been unfairly stated. 

 Lyell well knew the nature and work of glaciers in so 

 far as ascertained in his time. He had also collected a 

 large amount of information as to the conveyance of 

 lioulders, etc., by ice-bergs, and the formation of subma- 

 rine glacial deposits thereby. Lastly, he had profited by 

 the observations of the Arctic voyagers, and by those of 

 IJayiield in the river Saint Lawrence, so as to appreciate 

 the great carrying and erosive }K)W'er of heavy field ice. 

 His general theory of the glacial age was based on all 

 these factors, along with the gradual depression and re- 

 elevation of the continents in the pleistocene period. I 

 confess that I still adhere to his views in these respects, 

 with only such modification as to the relative value of 

 particular and local causes, as the ol)servations and reatling 

 of fifty years hate necessitated. 



My own conclusions with reference to the phenomena 

 observed in the Maritime Provinces of Canada, were ex- 

 pressed for the first time in the first edition of "xicadian 



