NA TURE 



193 



THURSDAY, JUNE 29, 1905. 



IHK FACE OF THE EARTH. 



The Face of the Earth (Das AiUlitz der Erde). By 

 Prof. Eduard Suess. Translated by Dr. H. B C. 

 SoUas, under the direction of Prof. W. J. Sollas, 

 F.R.S. Vol. i. Pp. xii+ 604; illustrated. (Oxford: 

 Clarendon Press, 1904.) Price 255. net. 

 ■pNGLISH-SPEAKING geologrists will be grateful 

 ■^ to Dr. Hertha Sollas and the Clarendon Press 

 for this excellent translation of the first volume of the 

 work which has probably had the deepest influence 

 on g-eological thought since the publication of Lyell's 

 " Principles." No higher complimerft could be offered 

 to such a book than that, twenty years after its publi- 

 cation, it should be worth while to issue a translation 

 without amendment, comment, or other addition than 

 the author's charming letter of introduction. This 

 fact is all the more striking as this volume is mainly 

 a description of the geology of the mountains of the 

 world, and it describes areas of which comparatively 

 little was known in 1884. As Prof. Suess remarks in 

 his introduction, " the reader will meet here and 

 there in the two first volumes with a description 

 already antiquated." This matters the less since we 

 have already an excellent French edition, which has 

 been brought up to date by abundant references to 

 recent literature, and been illustrated by an additional 

 series of maps. The example of the French trans- 

 lators has not been followed, perhaps from the senti- 

 mental feeling that as this work is now one of the 

 recognised classics of geology, it should be rendered 

 into English exactly as it came from the hands of 

 the master. This decision will no doubt increase 

 the value of the Oxford edition to future geologists, 

 though it mav detract somewhat from its immediate 

 educational usefulness. The absence of the extra 

 maps is an especial drawback to British students, 

 since nianv of the place-names used are synonyms or 

 transliterations not usually adopted in British atlases. 

 Anything that lessens the educational value of this 

 edition is regrettable, as .Suess's work is such 

 magnificent educational material. Prof. Suess's 

 method is to give the detailed evidence upon which he 

 relies ; and his readers have the pleasure of working 

 up to the conclusions by the path the author trod. 

 We sec his mental process as well as read his results. 

 This volume opens with a brief statement of some 

 of the geographical homologies which it is the object 

 of the whole work to explain. Prof. Suess dismisses 

 all geometrical plans of the earth, such as Elie de 

 Beaumont's famous Pentagonal reseau, as mislead- 

 ing \Vills-o'-the-wisp. He fully realises that the first 

 essential to an explanation of the present distribution 

 of oceans and continents is a: competent comparison 

 of the facts. As he says, a detailed comparison of 

 observations is necessary before an attempt be made 

 to formulate laws. Suess declines hints as to 

 probabilities from geodesy, and he distrusts specula- 

 tion as to the hidden parts of the earth. So he studies, 

 with exquisite care, those deeper parts of the crust 

 which have been brought to the surface in the exposed 



NO. 1 86 1, VOL. 72] 



roots of mountains, or which are opened to view by 

 the work of the miner. The two parts of this volume 

 are devoted to a study of the movements in the crust 

 of the earth, and to a description of the mountain 

 system of the world, e.xcluding Australia and some 

 parts of other continents. Prof. Suess concludes from 

 his synthetic study of this wide range of material 

 that the earth's crust is disturbed by movements of 

 two different kinds; firstly, the folding and crumpling 

 of belts of the earth's crust by lateral pressure; and 

 secondly, the foundering of the crust owing to the 

 withdrawal of underground support, consequent on 

 the radial contraction of the globe. Before Suess's 

 time it was usual to regard the distribution of land 

 and water as determined by the uplift as well as the 

 sinking of wide regions. But according to Suess, 

 regional uplifts have never yet been proved, and, 

 excepting perhaps to some local extent, he regards 

 them as impossible. An actual uplift of the surface 

 of the western coast of South .America was said to 

 have resulted from the earthquakes of 1822 and 1835. 

 The uplift of the latter was described by Darwin ; 

 but Prof. Suess discusses the evidence and dismisses 

 it as wholly inadequate. Any horizontal uplift being, 

 according to Suess, impossible where horizontal 

 marine beds, beaches, or shore-lines occur above sea 

 level, they must be explained by the lowering of the 

 sea, and not by the uprise of the land. Prof. Suess 

 does not hesitate to believe, on the evidence of the 

 plateaus of the Rocky Mountains, that the sea level 

 once stood 30,000 feet higher than at present. If 

 Prof. Suess were to discuss the possibility of regional 

 uplift at the present time, he would have to deal with 

 much weightier evidence than any which he had 

 against him in the year 1884. For the secular uplift 

 of the lake regions of the United States is better 

 established than any of the supposed earthquake 

 elevations of Chili. Moreover, the doctrine of isostasy 

 gives better reason to believe in its possibility. The 

 pendulum work in the Rocky Mountains has rendered 

 it at least possible, that isostasy may account for the 

 horizontal deposits of the high plateaus, which Prof. 

 Suess has described in one of the most brilliant 

 chapters of this volume. 



Regional uplifts, however, being dismissed by Prof. 

 .Suess, it follows that the main influence in shaping 

 the continents has been the subsidence of wide tracts 

 of the earth's surface beneath sea level. The great 

 ocean basins, and those of the Mediterranean, the Black 

 Sea, and the Caribbean Sea, represent sunken areas 

 of the earth's crust; and foundering to a less depth 

 has caused the rift valleys of Ethiopia, of the Rhine 

 and of .Australia, and the basins of Suabia and 

 Franconia. The cause of such subsidences is deep- 

 seated, whereas the crumpling of the long, narrow 

 belts that form the folded mountain chains Is due 

 to comparatively superficial action. The two modes of 

 movement may act in the same area at different times. 

 Thus vertical subsidences may destroy the continuity 

 of a folded mountain chain ; thus the present form of 

 the Basin Ranges of Utah and Nevada is due to the 

 breaking up, by Cainozoic subsidences, of a series 

 of ranges formed by earlier, post-Jurassic folds. 

 Similarly the outlines of the continents, even when 



K 



