NA rURE 



433 



THURSDAY, MARCH 12, 1896. 



A GLACIAL HANDBOOK. 

 Ice- Work Present and Past. By T. G. Bonney, D.Sc, 

 F.R.S., &c. Pp. xiv + 296. (London: Kegan Paul, 

 Trench, Triibner, and Co., Limited, 1896.) 



THIS latest addition to the familiar red volumes of the 

 International Scientific Series is in many respects 

 a model of what we may take to be the aim of the whole 

 series. An exposition of the results of modern research 

 and modern thought, which shall be of an unrestricted 

 and international character, written without offence to 

 prejudices or persons, is no mean task for an author to 

 set before himself And when the subject approaches 

 the chilling atmosphere of the ice-age, we know how 

 frequently the scientific soul waxes warm, and fortifies 

 itself towards the inevitable conflict ; while the outer 

 world exclaims, 



" That is hot ice, and wonderous strange snow." 



Has it been left for Prof. Bonney to " find the concord 

 of this discord " ? 



The aim of the author in this instance is to give 

 prominence " to those facts of glacial geology on which 

 all inferences must be founded." He begins most ap- 

 propriately with a description of a "gathering-ground of 

 glaciers " in the Bernese Oberland, a scene as familiar 

 to himself as Bedford Square or King's Parade must be 

 to many of his readers. A sober restraint is put upon 

 his powers as a word-painter, and we have a condensed 

 account of ice and ice-work in Switzerland, crisp and 

 clean as the surface of the snows themselves. It is true 

 that the irrepressible faculty of imagination breaks out 

 occasionally, seeing more before it than the upturned 

 face of the student ; and the contrast is almost too 

 abrupt, it betrays the effort at conciseness. Thus 

 we are uncertain whether the " struggle of Solferino" 

 (p. 35) refers to a meeting of descending glaciers, or to 

 the events of recent history, since all the other references 

 in the sentence are to purely geographical features. 



In this first chapter, certain conclusions are drawn from 

 the facts described, but so delicately and naturally that 

 they seem to involve no controversy. A confidence is 

 thus established between us and the author, and we follow 

 him with the secure feeling that theories may be sug- 

 gested, but will not be thrust upon us. If a writer has 

 formulated any opinion of his own, this is the very 

 happiest method of securing a hearing for it. 



The second chapter deals with the larger phenomena 

 of arctic and antarctic regions. To some extent this 

 traverses the ground of Prof Wright's corresponding 

 chapter in " Man and the Glacial Period " ; but addi- 

 tional matter is introduced, even in dealing with Alaska. 

 Attention is very properly drawn to the feeble character 

 of the "ground-moraine" in areas covered by an ice- 

 sheet, and to the great accumulation of the materials, in 

 the form of a terminal moraine, as the glacier retreats, 

 when they become (p. 48) " drawn very gradually, like a 

 coverlet, over the bed of the valley." On p. 57, another 

 point of first importance is set down with characteristic 

 delicacy ; "it is therefore obvious that in all speculations 

 NO. 1376, VOL. 53] 



as to the condition of any region during the Glacial 

 Epoch, account must be taken of the possibility of a not 

 inconsiderable difference in either direction from its 

 present level." The evidence bearing on this subject has 

 been so freely overlooked by those who have felt it easier 

 to accept enormously thick ice-sheets, rather than differ- 

 ential earth-movements, that this innocent little sentence 

 suggests in reality a controversy ranging over both the 

 hemispheres. 



The description of the Malaspina Glacier near Mount 

 St. Elias in Alaska, quoted from Mr. Russell, naturally 

 forms the most interesting feature of this chapter. The 

 term " Piedmont Glacier " (p. 68), as it happens, would 

 have been explained more clearly in Mr. Russell's own 

 words. Since the date at which Prof. Bonney wrote this 

 account of the Chaix Hills, with their uplifted marine 

 glacial gravels, he has examined the additional evidence 

 of post-glacial elevation brought forward by Colonel 

 Feilden from Kolguev Island {(2uart. Journ. Geol. Soc, 

 London, vol. lii., 1896, p. 57). 



After this review of "existing evidence," Part II. 

 describes the " Traces of the Glacial Epoch." The dis- 

 cussion of the origin of lake-basins is concerned with the 

 greater lakes of the world, and the summing-up is in 

 favour of their hollows having been caused by earth- 

 movements. Eskers are dealt with in the same chapter, 

 and the accumulation of sands and gravels in the very 

 areas claimed by some authors as regions of excavation 

 is, in conclusion, neatly pointed out. After Mr. Russell's 

 description, quoted on p. 74, we are left somewhat in the 

 dark (p. 116) as to the probable origin of eskers. The 

 names of Hummel and Hoist might well have been 

 quoted in connection with the theories for which they are 

 respectively responsible ; and Ireland is so eminently a 

 land of eskers, that one is inclined to ask for a view or 

 section of an esker of home-manufacture, instead of the 

 figure from New Hampshire given us on p. 1 10. 



Why, again, in the next chapter, headed " Ice-work in 

 Great Britain and Ireland," is till illustrated from 

 " Seattle, Washington State," except for the fact that 

 Prof Wright's block is in the possession of the publishers 

 of this series ? All through. Prof Bonney has been some- 

 what badly treated in the matter of illustrations. The 

 Alpine drawing in Prof Wright's book is painfully rigid 

 and antique, and we should consequently have welcomed 

 a photographic view of the Aletsch Glacier to illustrate 

 Prof. Bonney's description. The frontispiece, showing the 

 results of ice-work, is the only novelty of the kind. Even 

 the scratched blocks figured are not from Finchley, or 

 Snowdon, or Glencullen, but from " the till of Boston," 

 which seems far away from an English author, even in an 

 international scientific series. 



Such drawings as are given had a special interest when 

 put before us by Prof Wright ; but it is hard that Prof 

 Bonney, who has trained a full generation of geologists 

 in England, and to whom the Alpine heights are as a 

 garden, should be compelled to select his most effective 

 illustrations from those of an American predecessor. 

 A few views of English boulder-clays, and erratics, and 

 roches moutonn^es, as they actually appear, would have 

 been at least refreshing. Our students know far too little 

 of their own islands ; and, in the case of Ireland, such 

 pictures would have been absolutely novel. 



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