PEEFACE. 



The object of these pages is to give an outline of what appear 

 to have been the most considerable physical changes experienced 

 in our continent since the beginning of the Pleistocene or 

 Quaternary Period. Several general works, by some of our 

 most accomplished geologists and archaeologists, have already 

 dealt with the subject in part, and it is impossible, therefore, that 

 a new essay in Post-tertiary geology can avoid discussing certain 

 evidence which is perhaps sufficiently familiar even to non- 

 specialists. But none of the treatises referred to quite covers 

 the ground I have endeavoured to occupy. While some of my 

 predecessors have examined the evidence principally from the 

 point of view of the archaeologist, and others from that of the 

 palaeontologist, my aim has been to describe in a more system- 

 atic manner than has hitherto been attempted that succession 

 of changes, climatic and geographical, which, taken together, 

 constitute the Historical Geology of Pleistocene, Postglacial, and 

 Eecent times. 



In a former work (The Great Ice Age) I have already dis- 

 cussed some of the questions which form the subject-matter 

 of the present volume, and to a certain extent, therefore, the 

 latter may be considered as supplementary to its predecessor. 

 The two works, however, are quite independent. The Great Ice 



