Feb. 14, 1889] 



NATURE 



365 



octavo. It is written from the point of view of the 

 author's nationality, and naturally such new matter as it 

 contains is chiefly in reference to the palaeontology of the 

 Austrian Empire. E. R. L. 



OUR BOOK SHELF. 



Textbook of Physiography. By Edward Hull, M.A., 



LL.D., F.R.S. (London : Deacon and Co., 1888.) 

 From the Director of the Irish Geological Survey we 

 should naturally expect a text-book of exceptional merit, 

 but we must confess at the outset that he has disappointed 

 us. In the first place, he does not seem to have a clear 

 conception as to the scope of his subject. Physiography 

 is essentially an introduction to the study of natural forces 

 and their effects, and consequently not only comprises 

 the various movements and physical features of the earth, 

 but also includes a study of the various forms of energy 

 and the properties of matter. Of the latter, Prof. Hull 

 has written nothing. Again, it is difficult to see for what 

 class of students the book has been written. It is evidently 

 not for beginners, being avowedly addressed to those 

 who have access to the Transactions of the learned 

 Societies ; and the treatment is far too superficial for 

 advanced students. 



The first part of the book is designated " Astronomical 

 and Introductory," the earth being considered in relation 

 to the other planets. The questions of latitude and 

 longitude, and a chapter on the moon, fall under this 

 head. This part of the subject is treated so briefly that 

 very careful reading will be necessary on the part of those 

 who are not previously acquainted with it. 



Part II. deals with " Terrestrial Physics and Dynamics," 

 and discusses the form and structure of the earth, vol- 

 canoes, and earthquakes. The theory of a viscous 

 stratum beneath the earth's crust is put forward as con- 

 fidently as if it were the law of superposition of strata, 

 and all reference to the objections which have been urged 

 against it is omitted. It would be hard to compress more 

 debatable matter into a page than has been effected in 

 the diagram which illustrates this theory (p. 55). 



The physical features of the globe, such as surface 



forms, oceans, coral islands, tides, air currents, and the 



functions of rivers and glaciers, are treated in Part III. 



Terrestrial magnetism also falls under this head, and 



this is really an excellent outline of the subject, as far 



as results go ; but practically nothing is said about the 



instruments which are employed. As a compromise 



between the views of Darwin and Murray regarding coral 



reefs. Prof. Hull suggests (p. no) that "the volcanic 



islands and banks of organic materials are themselves 



planted on a floor formed by the surface of a continent, 



which once occupied the region of the Central and 



Western Pacific." We will leave the opposing parties to 



I form their own opinions as to the value of this suggestion, 



I The geographical distribution of plants and animals 



I forms the subject of Part IV., and here there is httle to 



I complain of. 



I The book is illustrated with thirteen coloured plates 



% and maps, and eleven diagrams. Some of these, as, for 

 [ example, the map showing the lines of equal magnetic 

 '( variation and declination for the British Isles, are excel- 

 *j lent. The whole book bears traces of having been written 

 I hastily, and we cannot but regret that the author of " The 

 I Coal-fields of (;reat Britain" should have added one 

 more to the already too large number of text-books that 

 seem to present physiography as a subject in which no 

 originality is possible. 



The Clyde, from its Sources to the Sea. By W, J. Millar, 



C.E. (London : Blackie and Sons, 1888.) 

 Mr. MiLL.^R has succeeded in writing an interesting 

 book about the Clyde, and about Glasgow in particular. 



The subject is worthy of the care devoted to it by the author, 

 for what river or city in the United Kingdom has more 

 varied industries to boast of, and where are the applica- 

 tions of science more numerous ? 



Probably no river owes its improvements more to 

 the engineer than the Clyde. We are told how eminent 

 engineers were called in, and surveys made, in order 

 to deepen the river and make it more navigable ; 

 Smeaton and James Watt each had their turn, and after- 

 wards many well-known men in their time reported on 

 the same subject. The result is that the Clyde of to-day 

 is able to float the largest ocean steamers in its harbour, 

 a state of things of which the people of Glasgow are 

 justly proud. 



The growth of the steam- ship, of course, occupies 

 much space, since it was on the Clyde the first successful 

 attempts at steam navigation were made. These are 

 duly described, and the boats illustrated. On recent 

 Clyde-built ships our author has much to say, and, 

 among other things, he gives an account of some experi- 

 ments conducted by the late Mr. William Denny to 

 investigate the relation existing between speed and resist- 

 ance of ships. Messrs. Denny, at their ship-building 

 yard at Dumbarton, have constructed an experimental 

 tank with all the requisite machinery for the purpose, 

 thus carrying on the mvestigations initiated by the late 

 Dr. Froude. 



This volume gives one a good insight into the varying 

 industries carried on in Glasgow and its neighbourhood, 

 and contains much general information about the dis- 

 trict. The book is well written, nicely printed and illus- 

 trated, and should find a place in the libraries of the 

 citizens of St. Mungo, and others interested in the 

 progress of the district. 



A Playtime Naturalist. By Dr. J. E. Taylor, F.L.S. 



(London : Chaito and Windus, 1889.) 

 Dr. Taylor explains that he has a liking for intelligent 

 English lads, " just as some people have for blue china 

 and etchings " ; and he " ventures to think the former are 

 even more interesting objects." Accordingly he has 

 written this little book for the instruction and entertain- 

 ment of his "human hobbies." The work contains 

 abundant evidence of the author's knowledge and enthu- 

 siasm, and any boy who may read it carefully is sure to 

 find something to attract him in the chapters on birds, 

 Lepidoptera. land shells, toads, frogs^ newts, invisible life, 

 microscopic plants, and other subjects. The style is 

 clear and lively, and there are many good illustrations. 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents . Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part op Nature. 

 No notice is taken of anonymous communications. 1 



The Climate of Siberia in the Mammoth Age. 



Prof. A. Newton, in his remarks on my letter, says that the 

 similarity of the birds of japan and of Europe has been long 

 known. Of course it has. it is an elementary postulate in 

 geographical zoology ; but this is not the fact to which I called 

 special attention, and from which I drew my inference. That 

 fact is that, while the birds of Japan and England are in certain 

 species undistinguishable, the corresponding birds of Siberia are 

 sufficiently different to be classed as separate species. This 

 could not be known, in the sense of benig iiroved, until the 

 avifauna of Siberia had been worked out from end to end, result- 

 ing in the formation of such a continuous series of skins as that 

 in the possession of my friend Mr. Secbohm. 



Prof. Newton goes on to argue that the remarkable fact here 

 referred to is to be explained by the hypothesis that the birds of 



