570 SCIENCE PROGRESS 



with the correlation of English results with Prof. Penck's 

 well-known scheme of four great Glacial Periods. The subject 

 is far from being new, and I have referred to it more than once 

 before in these notes. I had omitted to notice, however, that 

 at the end of an article entitled, " A Series of Humanly-fashioned 

 Flin s from Mundesley," in the same number of the above- 

 mentioned Proceedings, Mr. Reid Moir had discussed this very 

 subject, and had published a correlation of the East Anglian 

 results with the Penck scheme, his correlation being as detailed 

 as, but totally different from, that of Mr. Burkitt. Since we 

 have here two different interpretations of this most important 

 problem, one requires no excuse for returning to the matter. 

 Mr. Moir's scheme was published earlier than that of Mr. 

 Burkitt, but his point of view is less original than that of the 

 latter writer. 



Readers of Science Progress will probably remember that 

 James Geikie published an elaborate scheme of British Glacial 

 periods, which he was able to bring into close accord with 

 Penck's ideas. Geikie made a beautiful correlation in the 

 Munro Lectures of 191 3. He had four great Glacial Periods, 

 which appeared to fit in well with those of Penck, though he 

 called them by different names. Penck had three subsequent 

 minor cold phases : Geikie only two. But this discrepancy 

 was only apparent. Penck's first minor cold phase was 

 Pleistocene ; his other two were Recent. Both Geikie 's were 

 Recent. Hence Geikie's corresponded with Penck's second 

 and third (or sixth and seventh, if the reader prefers). Penck's 

 cold periods are called respectively Giinz, Mindel, Riss, Wiirm, 

 Buhl, Gschnitz, and Daun. Only the first four are usually 

 referred to as " Glacial Periods," but Geikie called them all 

 " Glacial Periods." This, however, is mainly a question of 

 words. It remains to be explained that there is a dispute about 

 the correlation of the Palaeolithic Ages with the Glacial Periods — 

 quite a distinct correlation-problem from that which we are 

 discussing, be it noted. Penck placed the Older Palaeolithic in 

 the Mindel-Riss Interglacial, and the Aurignacian in the 

 Riss- Wiirm Interglacial. Most French writers place the Older 

 Palaeolithic in the Riss- Wiirm Interglacial, and the Aurignacian 

 in the interval between Wiirm and Biihl, which interval is 

 known as the " Achen Recession." Geikie was in accord with 

 Penck. 



We turn now to the East Anglian series more particularly. 

 The key-problem here is, as Mr. Burkitt shows, the age of the 

 Chalky Boulder Clay. Geikie regarded it as Mindel. Other 

 writers, including Prof. Sollas (see Ancient Hunters, p. 560), 

 have suggested that it is Riss. Mr. Burkitt thinks that it is 

 Wiirm. In reference to previous writers, I may mention that 



