September lo, 1896J 



jVA TURE 



439 



marked and hear them struck on a clock. We think 

 therefore of an hour not as an interval of time, but as an 

 instant, which is that of the completion of the hour, 

 4 o'clock or 4 by the clock, meaninjf that four complete 

 hours have passed since the beyinniny of the clock-round. 

 When this is noon, and the hours afternoon hours, all is 

 logical enough. We are obliged to call the beginning of 

 the round the completion of the preceding ; because 

 though a clock may mark o, as clocks used in observ- 

 atories do, we cannot indicate nothing by a strike. Our 

 ordinary habit, however, becomes illogical when we speak 

 of morning hours and call them am. or ante-meridiem ; 

 for eight hours, for instance, before noon should mean 

 what we call 4 o'clock in the morning or 4 a.m. To be 

 logical, the morning or a.m. hours should diminish instead 

 of increasing ; but the usage cannot well be altered, and 

 it is not likely that ordinary people will ever adopt the 

 astronomer's plan and count the whole day through 

 twenty-four hours, even if astronomers try to conciliate 

 them by dropping their practice of beginning the day at 

 noon. For this there is now much less reason than there 

 was in early days of the science, when it was thought 

 desirable to keep a whole night's observations under 

 one date ; for modern astronomers make a considerable 

 number of observations in daylight and during the day 

 hours. W. T. LVNN. 



POPULAR GEOLOGY} 

 COME fifteen years ago, if a book had been published 

 ^ under the title of " The .Scenery of Switzerland,'' 

 the reading public might have expected glowing descrip- 

 tions of the magnificent mountains, the wild waterfalls, the 

 quaint chalets, the dangerous passes and precipices of 

 that wonderful Alpine rampart of Switzerland 



"Which serves it in the office of a wall, 

 Or as a moat defensive to a house, 

 Against the envy of less happier lands." 



And it would have been somewhat startled on opening the 

 book to find the first chapter dealing with the " (ieology 

 of Switzerland," and bristling with a supply of technical 

 tertns seldom to be found outside a geological text-book. 

 Nevertheless, that is how Sir John Lubbock's new book 

 opens, and the title is accordingly somewhat qualified on 

 the inner fly-leaf, where it reads in full, " The Scenery of 

 Switzerland and the Causes to which it is due." 



We have already had the esthetic aspect of the Alps 

 presented to us by such writers as -Symonds, Ruskin, and 

 Leslie .Stephen ; the mountaineering aspect by such 

 famous climbers as Whymper, Freshfield, and Conway ; 

 the scientific aspect by Forbes, Tyndall, Bonney and 

 others ; and now Sir John Lubbock seeks to combine the 

 ;i?sthetic and the scientific aspects. It may be said at 

 once that the book supplies to the cultured tourist a want 

 which has been felt more and more for some years. Years 

 during which Dr. Lunn's ine.xpensive tours have brought 

 a journey to .Switzerland within the reach of modest in- 

 comes, and when popular lectures on physical and geo- 

 logical subjects have attracted ever-increasing interest. 

 Besides, these are fin de siicle days, when the mere 

 sensuous enjoyment of the beauties of Swiss mountains is 

 not enough to gratify the tourist I He wants to surmount 

 their difficulties, either physically by climbing their sum- 

 mits, or mentally by mastering the secrets of their 

 structure — to come and see— yes, but also to conquer the 

 grandeur of the Alps I 



The intellectual conquest of the .•\lps, however, is not 

 yet completed by geology, and this is the very fact which 

 has restrained many of the veteran geologists abroad 

 from attempting a popular book on the subject. Prof 



1 " The Sccnerj' of Switzerland, and the Causes to which it is due." By 

 the Right Hon. Sir John Lubbock, Bart., M. P., F.R.S., Slc. Pp. 473. 

 (London : Macmillan and Co., Ltd. 



NO. 1402, VOL. 54] 



Fraas published in 1892 a useful book called " Scenerie 

 der Alpen," which eri-ed in being too geological for the 

 ordinary tourist. In 1894, the Committee of the Inter- 

 national Geological Congress published a special " Livret- 

 Guide " of Switzerland, wherein pedestrian tours are 

 planned and described geologically by the best Swiss 

 authorities on the various areas of the Alps. With these 

 exceptions, Sir John Lubbock entered an open field, and 

 has done so with considerable success. 



The book numbers 473 pages, arranged in twenty-five 

 chapters. About two-thirds of it are devoted to the geolo- 

 gical caxxses, while one-third discusses \\\i physical causes 

 which have moulded the surface features of Switzerland. 



It is perhaps rather unfortunate that the book begins 

 with three such difficult chapters as those entitled "The 

 Geology of Switzerland," "Origin of Mountains," and 

 "The Mountains of Switzerland." In the opening pages 

 the reader finds himself perforce initiated into the involved 

 question of the origin of gneiss. 



" The foliation of Gneiss is probably of two kinds : the one 

 due to pressure, crushing, and shearing of an original igneous 

 rock such as Granite, the other to original segregation-structure " 

 (P- 3)- 



A sentence like this cannot but be a stumbling-block to 

 the ordinary reader. Granite, Serpentine, the Crystalline 

 Schists, and the successive geological periods from Car- 

 boniferous to IVFiocene and Glacial time are briefly dealt 

 with. The second chapter contrasts " Table Mountains '" 

 with " Folded Mountains," and demonstrates that the 

 Swiss mountains belong to the latter class, having been 

 " thrown into folds by lateral pressure." Geological 

 terms — such as outcrop, dip, and strike ; fold, fault, and 

 fold-fault ; anticline, syncline, slickenside, and cleav- 

 age are explained ; various examples are also given 

 of the dynamo-metamorphic changes induced in rocks. 

 Attention is directed in the third chapter to the fact 

 that the main longitudinal valleys {eg. the Rhone-Rhine 

 valley which cuts through Switzerland in the direction 

 of the main axis, S.W.-N.E.) occupy the troughs of the 

 mountain-folds, whereas the transverse valleys [e.g. the 

 Reuss and Ticino in N.W.-S.E. direction) are inde- 

 pendent of the folds, being "entirely due to erosion." 

 Denudation of the surface is discussed, and the geological 

 proofs are given of the former presence of an arch of 

 sedimentary strata above the crystalline rocks of the 

 central chain of the Alps. Three well-known geological 

 sections illustrate the text— Schmidt's section from the 

 Rhone valley at Viesch to the Averser valley in the 

 Engadine, Favre's "Mont Blanc" section, and Heim's 

 " Windgaile and St. Gothard " section. A computation 

 "gives 4500 metres or, say, 14,000 feet, which erosion 

 and denudation have stripped from the summits of the 

 mountains ! " (p. 66). 



There follows a lighter series of six chapters on 

 glaciers, valleys, rivers, and lakes. The physics of ice and 

 ice-movement, and the characteristic features of glaciers 

 are carefully described. Evidences of the " Former 

 Extension of Glaciers " are considered, and abundant 

 examples quoted of the influence which ancient moraines 

 had in diverting the courses of rivers and damming up 

 lakes. The chapter on " Valleys " leads us into some 

 confusion of ideas. A " fault valley " is said to be " com- 

 paratively rare " (p. 143). The writer repeats the prin- 

 ciple mentioned above, that cross-valleys are valleys of 

 erosion, while longitudinal valleys are of geotectonic 

 origin. But he then asks himself the question, "Why 

 should the rivers, after running for a certain distance in 

 the direction of the main axis, so often break away into 

 cross valleys ?" (p. 148). " Three possible explanations," 

 suggested by Prof. Bonney, are given, and then the 

 following passage occurs : — 



" Under these circumstances I have ventured to make the 

 following suggestion. If the elevation of the Swiss mountains 



