PHYSICAL GEOLOGY. ] 79 



ascribed to the presence of an extensive continent, *' Arctis/' situated 

 at some distance from the present coast of Norway, between Scotland 

 and Spitzbergen, in consequence of which the warm gulf-stream was 

 excluded from the Norwegian coast, and also from the Arctic Ocean 

 between Spitzbergen and Nova Zembla. Gradually the " Arctis " land 

 sank, so that, at length, a passage was opened for the gulf-stream from 

 the Atlantic to the North Sea, and thence to the coast of Norway and 

 the Arctic Ocean, as in the present day. . E. E. 



Pfaff, Dr. P. Ueber die Bewegung und Wirkung der Gletscher. 

 [Motion and action of glaciers.] Pogg. Ann. Bd. cli. pp. 325-336 

 (woodcut), and Sitzungsb. phys.-med. Soc. Erlangen, Heft vi. pp. 

 34-44. 

 Discusses the laws of the motion of glaciers, describes experiments with 

 the author's microgoniometer on the Aletsch glacier, and argues against 

 the theory of the formation of valleys by glacial erosion. F. W. K, 



PiCTON, J. A. Notes on the Phenomena of Glacial Action in Nor- 

 way. Proc. Liverpool Geol. Soc. session 15, pp. 19-46. 

 Describes observed cases of the alternate advance and retreat of 

 Norwegian glaciers and other glacial phenomena. "Refers to Prof. 

 Forbes's observations and to Prof. Esmark's descriptions, translated in 

 Edin. New Phil. Journ. 1827. Quotes from a paper, <'La Neve de 

 Justedal et les Glaciers," 1870, by M. de Seur, wherein the production 

 of the granular snow called " Firn " is explained. The production of 

 Giants' Cauldrons is attributed to the arrest of a boulder at the base of 

 a glacier, the onward motion of which caused the stone to rotate ; and 

 cavities on the mountains called ^'Bottener'' are looked upon as half- 

 finished cauldrons. C. E. De R. 

 Kae, Dr. John. On some Physical Properties of Ice ; on the Trans- 

 position of Boulders from below to above the Ice ; and on Mam- 

 moth-remains. Phil. Mag. ser. 4, vol. xlviii. pp. 56-61. 

 The finding boulders on the surface of ice does not prove that they 

 have fallen or been deposited on it. "When ice forms on a tidal shore 

 the boulders that may be near low-water mark at first break through, 

 but afterwards, as the ice thickens, become firmly fixed and at last 

 completely enclosed in ice. In the spring, by thaw and evaporation, the 

 upper surface (say 3 feet) is removed, and the boulders appear lying 

 on the top. The last part describes how Mammoth-remains become 

 imbedded, and why their heads are commonly turned to the south. 

 The head sinks deeper and becomes enclosed, while the body swings 

 to the currents, which, in Siberian rivers, is from the south. F. D. 

 Reade, T. M. Tidal action as a Geological cause. Proc. Liverpool 



Geol. Soc. session 15, pp. 50-72. 

 States that Avind-waves have never been felt at greater depths than 

 10 fathoms, while the free tide-wave affects every particle down to the 

 most profound depth. Argues that, contrary to the general opinion, 

 denudation does go on over the bottom of deep seas by means of tidal 

 currents. C. E. De R, 



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