SrRFACE PHENOMENA. 181 



denudation and the action of wind-drift currents as agents of transport. 

 Part li treats of certain geological phenomena indirectly produced by- 

 wind, including the effect of air-pressure on volcanic eruptions and 

 on earthquakes. F. D. 



Dana, J. D. Note on Erosion. Amer. Jouni. sor. 3, vol. xii. pp. 192, 

 193. 



Attributes much of the eroding action of rivers to the direct force of 

 the water itself, without the aid of carried detritus. Soft rocks tlie river 

 wears away bit by bit ; harder rocks it tears up by the joints. Such 

 work will greatly increase with the increased velocity of floods. 

 Similarly, glaciers do more by the ploughing action of the ice itself 

 than by means of stones at the bottom. F. D. 



Dumas-Vence. Notice sur les cotes de la Manche. [On the shores 

 of the British Channel.] liev. Mar. Col. vol. xlviii. pp. 371-414, 

 727-772. 



Investigates the accounts of changes of the coast-line, whether from 

 erosion by the sea or from upheaval or subsidence. 



Ebray, Th. Stries pseudo-glaciaires. [Pseudo -glacial Striae.] Bull. 



Soc. Geol. France, 3 ser. t. iv. pp. 55, 56. 

 Note on possible non-glacial explanation of some striated pebbles. 



Evans, John. On the Percolation of the Rainfall on Absorbent 



Soils. Proc. Inst. Civ. Eng. vol. xlv. pp. 208-216. 

 Results of experiments with ordinary soil of Hemel Hempstead, 

 Herts, and with fragments of Upper Chalk. 



Fisher, Rev. 0. On the Theory of the Erosion of Lake Basins by 

 Glaciers. Geol. Mac/, dec. ii. vol. iii. pp. 253-255. 



Observations at the edges of glaciers tell us little of what goes on 

 beneath the central part of an ice-field. If the Swiss lakes were 

 excavated by ice, it was when the ice spread far beyond its present 

 boundaries, and under conditions diff'erent from those now observed. 

 There must be more or less water between the ice and the bottom of a 

 lake-basin ; and, for the ice to touch the bottom it must rise above the 

 level of the outlet. The ice would be thawed by contact with the rock ; 

 and so a continual circulation of water would be set up from even 

 the deepest part of the lake-basin toward the outflow. This water 

 must have an abrading effect. W. T. 



Mr. Milne on Floating Ice. Geol. Mag. dec. ii. vol. iii. 



p. 379. 

 Criticises Mr. Milne's account of icebergs, &c. (see p. 185). 



Foulerton, Dr. J. The Glacial Period. Proc. W. Lond. Sex, Aasoc, 



vol. i. pp, 04-66. (Abstract.) 

 Description of glaciers, and of the evidence of glacial action. 



