276 SCIENCE PROGRESS 



of the cold cycles ; in fact, for all we know, it might not involve a tilt 

 great enough to cause a pronounced glaciation at all during several cycles 

 together. 



I am sorry to see the objection put forward again that an increased 

 obliquity does not ipso facto cause the extension of polar ice. Persons holding 

 this view must have very crude notions about this substance, and probably 

 judge from their home experience of ice, which never attains a low temperature 

 in our winters. Ice can store cold to any degree, and resists melting to an 

 extraordinary extent. One might ask why, with our present obliquity, we 

 have any polar ice in the Arctic regions at all with nearly six months of con- 

 tinuous sun, or why glaciers do not melt right away in the valleys. Scott 

 says the temperature of surface snow in Lat. 77 South never was above 0° F. 

 during midsummer, and Nansen records a similar experience. It is not a 

 question of heat distribution, pace Mr. W. B. Wright, but of ice temperatures, 

 which is quite another thing. With an increase of obliquity the " Arctic 

 circles " must encroach on the temperate zone with an enlarged ice area, 

 or this term would have no place or meaning. The very word " climate " 

 is in origin " inclination," be it observed.^ 



Again, Messrs. Chamberlain and Salisbury have not it all their own way 

 about the rate of advance of the polar ice. American and Swedish geologists 

 estimate that it spread much more rapidly — 700 miles in less than 8,000 

 years 2 — and we have the testimony of Mr. Ponting, a member of the Antarctic 

 Expedition, who stated that the ice had receded thirty-six miles in the last 

 forty years. The rate of the retreat of the Muir glacier in Alaska has been 

 almost as rapid. Captain Scott also gives a picture of a valley from which 

 3,000 feet depth of ice had disappeared, showing that this process was by no 

 means a temporary change of climatic conditions {The Voyage oj the "Dis- 

 covery," vol. ii, p. 293). 



One might think, also, from this correspondence that the conclusions of 

 Swedish geologists stood alone, and that they were based on very hypothetical 

 data, instead of being fully endorsed by opinions in North America, India, 

 Australia, and New Zealand, which remove all possibility of regarding their 

 agreement with Drayson as a coincidence. Mr. G. F. Wright, of Ohio, writes 

 in Origin and Antiquity oj Man as follows : 



" The combined efiect of all this evidence is irresistible. Large areas in 

 Europe and North America which are now principal centres of civilisation 

 were buried under glacial ice thousands of feet thick while the civilisation 

 of Babylonia was in its heyday. The glib manner in which many writers, as 

 well as many observers of limited range, speak of the Glacial Epoch as far 

 distant in geological time is due to ignorance of facts, which would seem to 

 be so clear that he who runs must read them." 



I am glad to infer that my critic has not yet read the evidence of the 

 submerged forests, as given by me, which seems to me wholly convincing, 

 though a sometime president of the Geological Society said that he had studied 

 these forests and saw none of the signs of glaciation. Did he expect to find 

 glacial moraines or striated beach pebbles ? ^ Another geologist, equally 

 eminent, said he agreed with the conclusions of Swedish geologists regarding 

 a recent glaciation in Sweden ; * but it seemed to be of limited importance to 



1 Greek " klinein." 



2 Estimate based on the rate of advance of ice at present. Doubtless the 

 rate was more rapid during the abnormal conditions of the ice phase. 



^ The late Mr. Clement Reid, the author of Submerged Forests (Cambridge 

 University Press), told me he was quite ready to accept the fact of a recent 

 glaciation. 



* The region of glaciation extends to the province of Skania quite in the 

 south of Sweden, in 57° lat., corresponding to that of Aberdeen, 



