PHYSICAL GEOLOGY. 186 



Jahrh. h.-h. geol. Reichs. Bd. xxv. Heft 1, pp. 97-128 ; 2 wood- 

 cuts. 

 "Muren" and " Rufen" are local names given to the deb&cles of water, 

 mud, and rock masses, which occur, chiefly in consequence of the cutting 

 down of forests, in the Alps. Their effects are described, the causes 

 shown, and remedial precautions laid down. E. B. T. 



Lebour, G. A. The Geological Aspects of Rock- work. A chapter 

 (10 pp.; woodcuts) in i^o6nison's "Alpine Plants." Ed. 2. London. 

 A sketch on the natural weathering of rocks. 



Mackintosh, D. Questions concerning the Geological Action of Ice. 

 Geol. May. dec. 2, vol. ii. pp. 191, 192. 



Believes that until we know more about the behaviour of ice in 

 Greenland we shall not be able to understand the glacial phenomena of 

 these Isles. Addresses a series of questions to the officers of the Arctic 

 Expedition, calling attention to those points that most require investi- 

 gation. J. G. G. 



. Origin of Escarpments and Cwms. Geol. Mag. dec. ii. vol. ii. 



pp. 5G9, 570. 



Points out that the substance of many of the arguments lately 

 advanced by Messrs. Kinahan and Goodchild had been published by him 

 some years ago. J. G. G. 



Martin, Charles. Recherches Recentes sur les Glaciers actuels et la 

 Periode Glaciaire. [Existing Glaciers and the Glacial Epoch.] 

 Bevue des deux Mondes, Apr. 15, p. 26. 



Points out that the line of perpetual snow is really the line of neve, 

 and that this is too dependent on local conditions to be the subject of 

 calculation. Describes some recent variations of Alpine glaciers, also 

 their effect in condensing the moisture of the neighbouring atmosphere: 

 the glacier of the Rhone condenses 3450 cubic metres of water an hour. 

 Sketches the former extent of the Alpine glaciers. Discusses a dis- 

 covery of marine shells in a moraine at Camerlata (Como) ; speaks of 

 glacial action in Auvergne. Remarks on interglacial periods and the 

 Glacial Drifts of Britain. Concludes by discussing evidence for man's 

 existence in the Glacial period. T. G. B. 



Nordenskiold, Prof. A. E. On the Former Climate of the Polar 

 Regions. Geol. Mag. dec. ii. vol. ii. pp. 525-532. 



From the absence of traces of glacial conditions throughout the clear 

 sections of aU the rocks, from the Silurian to the Miocene, that have 

 been examined in the Polar Regions, and from the indication of tem- 

 perate (or even of warm) climates afforded by the general character of 

 the fossils from nearly all these rocks, concludes that Geology and 

 Palaeontology alike lend no support to the assumption that before the 

 Glacial Period there were periodical alternations of warm and cold 

 climates on the surface of the earth. J. G. G, 



