318 Britain's Heritage of Science 



memoirs to which students may turn for the latest and most 

 up-to-date views on each advancing front. Here we must 

 mention the two Geikies. Dr. James Geikie (1839-1915), 

 besides valuable memoirs on general geology, has given us 

 a summary of the arguments in favour of a correlation of 

 astronomical cycles with geological periods. Sir Archibald 

 Geikie has in text-book after text-book met the wants of 

 every age, and, in the clear and attractive language which 

 Scotsmen seem to have by nature, or to have evolved the 

 method of acquiring by education, has kept generations of 

 students supplied with accurate information as to the state 

 of the evidence on the many questions raised in the progress 

 of an advancing science. 



This may be called an age of text-books, many of them 

 entitling their authors to a foremost place among those 

 who are helping on the progress of science, but we cannot 

 here even give a list of their names. 



We are too apt to attach such importance to our modern 

 theories that we forget what a great advance an earlier 

 hypothesis had often made on pre-existing views. It was a 

 shrewd observation which induced the clever and courageous 

 Dean Buckland (1784-1856) to maintain that a large part 

 of the superficial deposits which are seen heaped up on the 

 tops and flanks of the highest hills and filling the deepest 

 valleys of the North of England must have had an entirely 

 different origin from the alluvial deposits such as we see 

 being laid down now, and to venture on the bold suggestion 

 that there had been in quite recent times a great sub- 

 mergence and that the sea once swept over the land and left 

 as the result of the deluge these tumultuous deposits hence 

 called Diluvial. 



Wider travel and more detailed work, however, showed 

 a closer analogy between most of these so-called Diluvial 

 formations and the masses of debris carried on, in, or under 

 the ice and left at its foot when the glaciers or ice sheets 

 melted. Agassiz pointed this out and a grand company of 

 Scotch and other geologists immediately set to work on the 

 details of every section to prove or disprove the truth of 

 each new suggestion. 



In the domain of Economic Geology William Smith's 



