GLACIAL MAX. SKERTCHLY. 135 



where no human eye could see anything but boulder-clay, 

 save stones from the bottoms of wells. Then we field-men 

 protested, and the mapping of the so-called superficial beds 

 was seriously taken up. Even then two sets of maps were 

 issued, the one showing the solid geology, the other drift maps. 

 At last when, as in Rutland, the drift occupied 90 per cent, 

 of the ground tliis ridiculous division was finally abandoned, 

 and now all our Geological Surv^ey maps shoAV all the beds that 

 appear on the surface. 



Louis Agassiz had demonstrated the former existence 

 of a glacial epoch, and we all thought the ice had come on 

 gradually, culminated, and passed slowly away. But we who 

 had to deal with the beds in our daily work soon found this 

 simple, free-and-easy theory would not work. All boulder- 

 clay \^'as not mere iceberg droppings ; most of it Avas the 

 ground- moraines of land ice — of glaciers. jMoreover, there 

 turned out to be not one but several boulder-clays, showing 

 that the Great Ice Age, as James Geilde felicitously dubbed 

 it, was a complex era of alternate cold glacial and compara- 

 tively warm interglacial periods. Great \n as the controversy 

 over this ; the older men strenuously insisting that the Glacial 

 Epoch, like the first French Repubhc, was one and indivisible. 

 In Scotland, among the doughtiest champions of the new 

 views were James Geikie and your old acquaintance Robert 

 Logan Jack — whom you see I have known for over forty j'cars. 

 In England. Searles-Wood junior and F. W. Harmer had 

 insisted on a similar state of things in East Anglia, and I soon 

 found the same true of the midland counties ; and a pretty 

 tough fight we had to get our official heads to come round to 

 our views. Anyhow I convinced Sir A. C. Ramsay, as you A\ill 

 see in his Geology of Great Britain. 



In 1874 James Geikie published his " (Jreat Ice Age," 

 which practically settled the question, at least for us field 

 geologists Avho were daily mapping the beds. Meanwliile I had 

 gone to Brandon and had arrived at conclusions curiously 

 like Geikie's, even to discovering a new series of interglacial 

 beds, in fragments, but unmistakable, to which I gave the 

 name of Brandon Beds. Also I had found that the chief 

 boulder-clay differed in constituent matter according to the 

 beds it passed over. From the nature of things this was much 

 clearer in England than in Scotland. I wrote to Geiki-e, who 



