220 



NA TURE 



\ytily 4, 1889 



our present knowledge. Signals and interlocking are 

 efficiently dealt with in chapter v. Then the telegraphs 

 are equally well described in chapter vi. The rolling- 

 stock of a railway forms probably the most important 

 part of the necessary plant, and is affected more than 

 anything else by the gradually increasing speeds and 

 weights of trains. Chapters vii. and viii. deal with this 

 important subject. The standard types of locomotives 

 are very well illustrated, but the descriptions might with 

 advantage have been more detailed. The author dis- 

 cusses the necessity for an increase of power in the 

 passenger locomotives to cope with the increased weight 

 of the principal express trains, and the solution of the 

 problem by the introduction of Mr. Webb's fine com- 

 pound locomotives. The construction and working of 

 these engines are described clearly enough for the benefit 

 of non-professional readers. It would have been interest- 

 ing to find an account of the Worsdell compound locomo- 

 tive, which, although not in use on the North-Western, has 

 many points in its favour. Comparing it with Mr. Webb's 

 engine, many engineers consider it the better engine of 

 the two. Perhaps in a future edition Mr. Findlay might 

 add a description of it, with an illustration. 



Carriages and different kinds of rolling-stock are well 

 dealt with, and it is evident that the author has taken the 

 utmost pains to get his information up to date. The 

 locomotive works at Crewe, and the carriage and waggon 

 works at Wolverton, are capitally described. With 

 reference to the automatic vacuum brake, described on 

 p. 120, it is evident that this brake is automatic on the 

 coaches as well as on the guards' vans. As this is prob- 

 ably of recent introduction, the North-Western Company 

 are to be congratulated on its adoption in their rolling- 

 stock. The earlier vacuum brake fitted was nothing more 

 than the simple non-automatic vacuum brake as far as 

 the coaches were concerned, and was justly condemned 

 by most railway engineers for that reason. 



The remaining chapters deal with the working of the 

 trains, shunting and marshalling of goods trains, the 

 working of goods stations, rates, fares, traffic, &c. With 

 regard to all these matters the writer's statements are 

 clear, concise, and to the point. 



It would be of great service to the railway world 

 generally if some of the head officials of the best English 

 railways would follow Mr. Findlay's example, and give us 

 some of their stores of experience. Take, for instance, 

 locomotive engineering : where is the student or appren- 

 tice to find a book of recent date on the design, con- 

 struction, and working of the modern locomotive ? Let us 

 hope that the infection will spread on the North-Western 

 staff, and that by and by Mr. F. W. Webb, the able 

 Locomotive Superintendent of that railway, will write a 

 book on the department in which he so greatly excels. 



Mr. Findlay's book displays so much knowlege and 

 ability that it well deserves to rank as a standard work on 

 the subject. N. J. L. 



UUR BOOK SHELF. 



Zur Geologie der Schweizeralpen. Von Dr. Carl 

 Schmidt. One Plate. (Basel : Benno Schwabe, 1889.) 



This pamphlet gives a summary of the views entertained 

 at the present time by many leading Swiss geologists as 

 to the geological history of the Alps. So far as we can 



see, it does not profess to be more than a compilation, or 

 to contain any original work ; but as a summary it is as 

 clear and concise as the subject permits. The author, 

 in the first chapter, briefly sketches the history of the 

 principal types of rock which enter into the composition 

 of the Alps ; and, as might be expected at the present 

 juncture, lays much stress upon the results of pressure. 

 Some, indeed, may think that the present moment is 

 rather inopportune for such a memoir as this ; for the 

 modifications due to pressure, especially in rocks already 

 crystalline, are still the subject cf so much controversy 

 among geologists, that it is difficult to know what maybe 

 taken for granted ; and there is a danger, if the writer be a 

 disciple of the new school, of confusing the results of 

 demonstration and of hypothesis. A quotation (trans- 

 lated) will indicate the author's point of view better than 

 a general statement. After pointing out that two great 

 rock groups exist in the Alps, one consisting of various 

 granitoid rocks, gneisses, and crystalline schists, the other 

 of limestones, sandstones, and other sediments, he proceeds 

 — " In Switzerland the region which intervenes betwe en 

 the two zones is not very broad. The general strike of 

 this intermediate zone is through Coire, Ilanz, the Greina 

 Pass, Scopi, Airolo, Nufenen, the Rhone Valley, to 

 Martigny, and so through the Val Ferret to the Little 

 St. Bernard. The rocks of this intermediate zone are 

 crystalline sediments, the age of which it is difficult to 

 fix with precision. In the Grisons they have lately been 

 claimed by Giimbel as Palaeozoic, in the Valais they have 

 been shown by Lory to be Triassic : that the same, from 

 the Greina Pass to the Nufenen, are Jurassic, can be 

 proved by fossils." This, however, begs the whole ques- 

 tion. It has yet to be shown that the Swiss geologists 

 have not confused together, as some maintain, two dis- 

 tinct rock groups, owing to their having mistaken (not 

 for the first time) for crystalline schists, deposits which 

 only simulate the latter, because they are locally com- 

 posed almost entirely of their debi'ls. 



But, putting aside theoretical and controversial matters, 

 the author's summary is generally clear. It would, we 

 think, have been more useful if he had condensed some- 

 what the general discussion in the opening chapter, 

 and dwelt more fully in the others on the many interest- 

 ing questions of local physiography which are opened up 

 by a study of the Alps. To this objection, however, an 

 exception must be made in the case of the nagelflue, 

 where Dr. Schmidt's remarks are very interesting. In 

 certain of these great masses of conglomerate, pebbles of 

 crystalline rocks are fairly common. These, he states, 

 whether granites, gneisses, or crystalline schists, show 

 no indications of the dynamic metamorphism which is 

 exhibited by similar rocks in the adjoiningchain of the Alps. 

 From this observation, if confirmed by further research, 

 it would result that the " schistosity," or secondary folia- 

 tion, which is so marked a feature in most parts of the 

 Alps, has resulted not from the post-Eocene but from the 

 post-Miocene set of movements. 



Die E?tfstehung der Arteji durch rdumliche Sonderung. 

 Gesammelte Aufsdtze von Moriz Wagner. Heraus- 

 gegeben von Dr. med. Moriz Wagner. (Basel : 

 Schwabe, 1889.) 



Of later years, zoological hterature has been significantly 

 full of contributions, advocating now addition to, now 

 subtraction from, the theory of " evolution by means of 

 natural selection " formulated by Darwin— contributions,, 

 the chief characteristics of which are that they are 

 mutually destructive, that they are, comparatively speak- 

 ing, unsupported by any serious array of observed facts,, 

 and that none of them meet with more than a few ad- 

 herents. We do not believe that truth is appreciably 

 advanced by ingenious speculation of that nature ; it is 

 certainly in so far retarded that the energy thus expended 

 would have been better applied in placing Darwin's con- 



