78 



NATURE 



[July 21, 1910 



and shook up the famous Muir Glacier so thoroughly 

 that its seaward end was disintegrated, filling Glacier 

 Bay with icebergs that barred out all shipping for 

 soriie years. Prof. Tarr gathered evidence proving 

 that the earthquake brought down huge avalanches 

 of snow and rock from the mountain-sides into the 

 glacier-basins, and he considers that the sudden 

 accession of material has exerted a thrust which has 

 swept slowly forward as a wave throughout the 

 length of the glaciers. He strengthens his conclu- 

 sion by showing that, at least in some cases, the 

 unaffected glaciers are those fed from gentler slopes 

 from which avalanches would be less likely. 



The e.xplanation raises many knotty points in the 

 still imperfectly understood physics of glacier-move- 

 ment, while the new facts constitute a very important 

 element to be taken into account in all future dis- 

 cussions of ice-flow. In reading the descriptions w-e 

 are reminded of the abnormal conditions found by 

 Garwood and Gregory in the Booming Glacier of 

 Spitsbergen (Quart. Journ. Geol. Soc, vol. liv., 1898, 

 p. 207), and of the rapid advance and subsequent 

 recession of the Hispar Glacier in the Karakoram 

 Range {Geographical Journal, vol. .xxxv., February, 

 igio, p. 108). Is it possible that a great mass of ice 

 may become suddenly more mobile when its tempera- 

 ture as a whole reaches some critical point short of 

 the melting stage? The glacial geologist could find 

 ready application for some such proposition if it were 

 presented to him with the requisite Q.E.D. 



Besides these features of central interest, Prof. 

 Tarr describes many other phenomena that will 

 arrest the attention of the geologist; for example, the 

 rock-channels cut by streams running along the 

 margins of glaciers, w'hich remind us of the old 

 " overflow channels " lately recognised in many parts 

 of Britain and Ireland; the "pitted plains," where 

 morainic deposits have been spread out by streams 

 in great "apron-fans" incorporating hidden masses 

 of ice (see Fig. 2) ; the sudden slipping of a small 

 mountain-glacier en ^nasse from its high corrie into 

 the waters of Disenchantment Bay, causing huge 

 waves that swept destructively on to the land; and the 

 spread of vegetation over the areas abandoned by the 

 ice. His re-discussion of the eflicacy of the glaciers as 

 erosive agents should also be read by everyone who 

 has shared in the long debate on this subject. The 

 memoir concludes with a short account of the solid 

 geology of the region, which is of less general 

 moment. 



We have scant space in which to deal with the 

 other two memoirs, and must perforce dismiss them 

 summarily. 



(2) Mr. F. L. Ransome's monograph describes an 

 area around Goldfield, on the hilly desert-plateau 

 countrv near the border of south-western Nevada, 

 which has recently sprung into prominence as a gold- 

 mining centre. His historical narrative has a touch 

 of romance in it — vast treasure lying close to the 

 surface, vet passed over again and again by eager 

 prospectors; then, in 1902, discovery — excitement — and 

 disappointment; in 1903-5, renewed search crowned by 

 success ; great fortunes rapidly made and lost in the 

 wild boom and its reaction, the feverish activity cul- 

 minating in a fierce labour dispute which necessitated 

 the calling up of federal troops at the close of 1907 ; 

 and finally, the consolidation of interests and the 

 svstematic ransacking of the ground. It is estimated 

 that the value of the precious metals recovered during 

 the years 1904-7 from this small field was close upon 

 20,000,000 dollars. 



.^s for its geology, the field is a low dome-like 

 uplift of Tertiary lavas with associated lake-sediments, 

 resting upon a sparingly-exposed foundation of ancient 

 granitic and metamorphic rocks. The ore-bodies, 



NO. 2125, VOL. 84] 



apparently deposited in late-Tertiary limes from 

 "acidified" solutions at no great depth, are remark- 

 able alike for their richness and for .their irregularity. 

 The structure, origin and mineralogy of the lodes, and 

 the petrology and chemical composition of the rocks 

 are fully discussed, and beautifully illustrated in the 

 plates. In respect to the eruptive sequence, the author 

 finds no proof of the regular order which J. E. Spurr 

 has sought to establish for the lavas of the Great 

 Basin. In criticising this scheme the author remarks : — 

 "To some minds the conformity here shown may 

 appeal as corroborative, but to others, impressed by 

 the scanty representation of the numerous members 

 of the ideal succession in any given locality, the capa- 

 city of the scheme for assimilating not only observed 

 sequences, but imaginary ones, raises doubt whether 

 it reallv represents natural processes " (p. 105). The 

 criticism might be applied to many another ingenious 

 scheme in science. 



(3) The San Juan Mountains in south-western 

 Colorado, like most steep mountains of similar struc- 

 ture, have been subject in the past, and are still 

 subject, to extensive landslips. Many examples of 

 these slips, both ancient and modern, are fully 

 described bv Mr. E. Howe in the third paper on our 

 list, and are pictured in many fine plates which almost 

 make description superfluous. .\ massive series_ of 

 Tertiary volcanic rocks, often carved into huge cliffs, 

 rests on a vielding base of soft Cretaceous shales; 

 and, among' the older sedimentary formations, are 

 thick Palaeozoic limestones resting on friable shales 

 and sandstones. /\ttention is particularly directed t > 

 the curious "rock-streams" which have their origi:-; 

 in the high cirques; and to the influence of snow 

 banks on the accumulation of talus at the foot of 

 cliffs. The memoir concludes with a somewh;it 

 laboured classification of landslides in which foreign 

 examples and their literature are freclv cited. 



■ G. W". L. 



MOUNTAINEERING IN THE NORTH-WEST 

 HIMALAYA.' 



ONE would hardly suppose, after reading this 

 simplv-told narrative of physical achievements, 

 that the senior member — and shall we say, with Mrs. 

 Workman's permission, leader— of the party among 

 the peaks and glaciers of the Nun Kun group was 

 compelled some years ago to retire from his medical 

 practice on account of ill-health. Evidently, at great 

 altitudes, where the vitality is lowered by insomnia 

 attending deficient oxygenation, and where mental 

 depression and attacks of irresolution follow a dis- 

 turbed circulation, the successful explorer depends 

 whoUv on having his muscles under the complete 

 control of a resolute mind for that last supreme fight 

 against the irresistible instinct to descend to his 

 natural environment. The .Arctic explorer can 

 sleep, can eat, and is the better for work 

 to do; the mountain climber handicaps him- 

 self by his load of protective non-conductors; 

 his respiratorv difl'jculties are increased when in the 

 only position' of rest left to the biped, and_ every 

 mo'mentarv doze through sheer exhaustion is ter- 

 minated bv frantic efforts to avoid the intolerable 

 feeling of 'suffocation. .Anyone who has experienced 

 these "troubles, which bes'et all climbers— even the 

 luckv few who are proof against mountain sickness 



will admire the mental as well as the phvsical 



qualities of the altitude record-breaker; for, judging 

 bv the recent sordid controversy among .Arctic ex- 



1 "Peak5 and Glaciers of Nun Kun: a R^corH cf Pinreer-Fsplorn- 

 tiral and Mountainesrine i" the Punjab Hirrnbya." P.v Fannv Kullock 

 Workman and Dr. W. H. Workman. Pp. XV + 2C4. (London: Constable 

 .ind Co., Ltd., 1909.) Price i8j. net. 



