626 



NA TURE 



[October 17, 1907 



WATER .l.VD ICE. TO-D.IV .lA'/) i.Y THE 

 GLACIAL EPOCH. 

 V[R. G. K. GILBERT'S survey of the Niagara 

 ■'■'■'■ Falls (see Nature, vol. Ixxv., p. 607) is not to 

 stand alone. In the " Summary Report of the Geological 

 Survey Department of Canada for 1905 " (Ottawa, 1906) 

 Dr. J. \V. Spencer promises a full account of the Niagara 

 district, which he is agreeably confident will reveal " dis- 

 coveries of the greatest importance " (p. 91). Soundings 

 have been made in the gorge below the falls, in areas 

 previously untested, and wells have been sunk to prove 

 the depth of an interesting buried channel, filled with 

 glacial drift. 



In contrast with this region of attractive turmoil and 

 erosion, Mr. T. W. Kingsmill takes us to the lower 

 Hwangho, in China, where the river " is prevented by 

 the laws of hydraulics from excavating its bed, and has 

 in consequence to flow on the surface " (" The Hydraulics 

 of Great Rivers Flowing through Alluvial Plains," 

 Shanghai, North China Herald Office, 1906). If once 

 this great body of water effects a breach in one of its 

 banks, it " shows no disposition, when the flood subsides, 

 to return to its bed, but invariably finds some easier 

 course to the sea." The Hwangho, 

 according to Mr. Kingsmill 's interest- 

 ing historic sketch, broke its right 

 bank in 1854, and from that date to 

 1870 wandered over a wide stretch of 

 country, depositing a layer of sand 

 from 6 feet to 8 feet thick. In 

 Horan, not far from Mangtsin, 250 

 feet of river-alluvium, thoroughly 

 pervious to the water above it, were 

 passed through in sinking for a coal 

 mine. Much of the drainage thus 

 reaches the sea by underground 

 channels, and the main river actually 

 diminishes in volume below Mangtsin. 

 The extensive deposits that are form- 

 ing in the Gulf of Pechili, at the rate 

 of 208,000 tons per day (p. 31), in- 

 crease the dillicully of controlling the 

 river in the interior. We learn that 

 fishermen on stilts may be met with 

 out at sea miles before the low coast 

 is sighted. Mr. Kingsmill's sugges- 

 tions for correcting the stream are 

 enlivened by the printing of a dis- 

 cussion of them by Mr. Tyler. Mr. 

 Kingsmill proposes to continue bank- 

 ing up the river ; Mr. Tyler would 

 organise floods at selected points, and 

 let the river build its huge conoidal 

 plain under proper supervision. The 

 silt would then be disposed of in an 

 orderly manner, and the river-bed 

 would cease to rise. The titanic 



struggle of man with the Colorado River (Nature, vol. 

 Ixw., p. 501) suggests, however, that Mr. Tyler's 

 ilumping-grounds might at times get more water and 

 less silt than they were prepared for. 



There are many districts that have been assailed by 

 diluvial flooding and deposition in comparatively recent 

 times, where now desiccation has set in, with the accom- 

 paniment of the formation of loss and sand-dunes. The 

 extremely uncomfortable conditions that prevailed in 

 Europe at the close of Glacial times are shown by Prof. 

 Steinmann to have been paralleled in South America 

 <" Uber Diluvium in Siid-Amerika," Monatsberichie d. 

 deiitschen geol. GeselL, 1906). The author believes that 

 the vast extent of fluvio-glacial deposits, which have filled 

 up the hollows of the Cordillera and spread so freely 

 over Patagonia, can only be accounted for by a series of 

 glacial epochs. He sees, moreover, in the level expanses 

 of calcareous mud round the salt-lakes of Bolivia and 

 Argentina the evidences of former fresh-water lakes, in 

 which Bythinia flourished. " 'The traces of the last ice- 

 age may be followed across the equator as far as Cape 

 Horn." The climatic differences that prevail at the pre- 

 sent day are now shown to have existed, both in Europe 

 NO. 1 98 I, VOL. 76] 



and South America, during the melting of the last ice- 

 sheets; and "hence we shall do well to discard all 

 attempts at explaining glacial epochs that are not of a 

 universal character." 



In a paper furnished with an abstract in French (" Till 

 Fragan om Ost-Finmarkens Glaciation och Nivaforiind- 

 ringar, " Bull. Comm. gcol. de finlande. No. 18, 1907), 

 Herr V. Tanner describes the course of the ice in Fin- 

 mark in glacial times as being from S.VV. to N.E., and 

 traces the variations in the sea-level by observations on 

 terraces cut in the rock and on gravelly raised beaches. 

 While the ice was melting from the land, the continental 

 mass was rising, and thus offered a more and more ex- 

 tended front to the action of the waves. 



While the terminal tongues of glaciers in Alberta and 

 British Columbia have not in all cases shown a marked 

 retreat in recent years, Messrs. George and W. S. Vaux 

 prove that the ice-masses have become greatly reduced 

 (Proc. Acad. Nat. Sci. Philadelphia, December, 1906,. 

 p. 568). The Illecillewaet Glacier has withdrawn about 

 250 feet in eight years ; but its annual rate of recession 

 is becoming slower, and its rate of flow is now actually 

 greater than in 1899. Conical moraines appearing 

 through the ice on the Wenkchemna Glacier (p. 577) are 



Fig. 



-Margin of the ] 



witnesses of the immense amount of ice removed in recent 

 times by surface-melting. 



The famous Malaspina Glacier of Alaska has, however, 

 started on a new career. Prof. R. S. Tarr (" Second 

 Expedition to Vakutat Bay, Alaska," Bull. Geographical 

 Society of Philadelphia, January ; see also Bull. Gcol. 

 Soc. America, June) describes the rapid and un- 

 expected changes that are taking place in it, and in 

 certain other glaciers close to its eastern margin. 

 Crevassing has occurred in previously quiescent and 

 moraine-covered masses, accompanied by a marked 

 advance. Prof. Tarr found that the alder and cotton- 

 wood trees growing on the Malaspina Glacier developed 

 their leaves in 1906, but were then in part swallowed up 

 and over-ridden by the active ice. The scene of visible 

 movement, with falling trees and ice-blocks, and sliding 

 soil from the moraines, is paralleled by the attack of the 

 adjacent Atrevida Glacier on its marginal forest. Other 

 glaciers as yet have not been influenced ; and Prof. Tarr 

 refers these remarkable movements to the shaking of the 

 district by the earthquakes of 1899, or even of some 

 earlier date. The fall of masses of snow into the gather- 

 ing-grounds would thus have taken seven years to in- 



