November 29, 1894] 



NA TURE 



lOI 



bustion, in the coal basin of Decazeville and Aubin. His 

 description also of the irreparable mischief wrought by 

 the reckless destruction of forests, is well worth reading, 

 for it must be remembered that the weird desolation of 

 the limestone plateaux is a thing of comparatively recent 

 date, and an indirect consequence of the French Revolu- 

 tion. Of the rock shelters of the " reindeer age" in the 

 valley of the Dordogne and of other rivers, he has much 

 to say, and of the dwellers in " holes of the rock " down 

 to the present day ; for these caves have been enlarged, 

 or faced with masonry, or actually excavated, at various 

 dates, and in some cases are still inhabited. Of the 

 dolmens and other megalithic remains which are com- 

 mon on the plateaux region, Mr. Baring-Gould writes as 

 one who has made a study of the subject. Perhaps some 

 of his ethnological speculations may not meet with uni- 

 versal acceptance, but they are, at any rate, worth con- 

 sidering. The book contains many curious bits of 

 folk-lore, as we might expect, and narrates sundry 

 remarkable historical episodes in the medix'val struggle 

 between France and England, and in the spnguinary 

 conflicts of Huguenots and Romanists. A chapter is also 

 devoted to the romantic, though often discreditable, story 

 of Jo.ichim Murat, who was born at a dirty little " bas- 

 tide " of the same name on the Causse de Gramat, near 

 the source of a tributary of the Lot. The book, in short, 

 while it indicates the author's cultivated tastes and wide 

 range of reading, directs the attention of travellers to a 

 region of singular and varied interest, which hitherto 

 has received but little notice even from the French 

 themselves. It is only inadequately described in 

 Reclus' great work, "Gdographie Universelle." It has 

 not, however, escaped the indefatigable emissaries 

 of Baedekker, who gives, in the volume on Southern 

 France, a succinct account of the district, evidently 

 founded on personal knowledge. Armed with the little 

 red book, and Mr. Baring-Gould's more bulky volumes, a 

 rich reward undoubtedly awaits the visitor. The guide- 

 book will direct his steps aright ; Mr. Baring-Gould's 

 pleasantly written and admirably illustrated volumes will 

 give him abundant information about the chief points of 

 interest, whether physical, archaeological, or historical, 

 and will be an unfailing resource during those hours of 

 enforced leisure, which, on a journey, are apt to become 

 tedious. T. G. Bonnev. 



OUR BOOK SHELF. 



An Eliinentaiy Treatise on Theoretical Mechanics. 

 Part 1. Kinematics. Part II. Statics. By .Mexander 

 Ziwet, Assistant Professor of Mathematics in the 

 University of Michigan. (London and New York: 

 Macmillan and Co., 1893.) 



Amkric.an mathematicians have always followed the 

 system of the French and continental school, so that the 

 progress of the .American student in analytical develop- 

 ment has not been arrested and stunted by the excessive 

 reverence of the Newtonian methods prevalent in this 

 country. 



According to the continental system a student is 

 introduced at the earliest possible stage to the Cartesian 

 methods of geometry and to Leibnitz s extensions in 

 the domain of the Differential and Integral Calculus ; 

 and then, even with a comparatively small equipment 

 of analytical knowledge, hardly extending beyond an 



NO. 1309, VOL. 51] 



acquaintance with the notation, he is prepared to study 

 and appreciate a work like the present ; while the Eng- 

 lish student is kept back by clumsy antiquated methods, 

 on the pretext of developing his geometrical and general 

 reasoning powers. 



This work is intended as an introduction to the science 

 of theoretical mechanics, adapted to the particular wants 

 of engineering students who, with the characteristic 

 practical energy of their race and age, will not desire to 

 be kept marking time over the rudiments. 



The general treatment of the subject is elegant and 

 complete, and valuable collections of illustrative examples 

 are introduced at the different stages. One of these, 

 however (ex. 6, § 276), caught the eye, as requiring amend- 

 ment ; as also the Fig. 29 of the catenary. 



.•\n old friend, the problem of the beam in a bowl — in 

 other words, of a spoon in a teacup — given as ex. 20, 

 g 151, deserves separate discussion, and a complete 

 solution in the text. 



The present opportunity is favourable for expressing to 

 Prof. Ziwet the thanks of mathematicians in this country 

 for his valuable Report of Prof. Klein's Lectures on 

 Mathematics, called the " Evanston Colloquium," held 

 before members of the Congress of Mathematics in 

 connection with the World's Fair at Chicago, at North 

 western University, Evanston, 111. G. 



By Order of the Sun to Chile to see his Total Eclipse, 

 April 16, iSg-^. By J. J. Aubertin. Pp.152. (London: 

 Kegan Paul, Trench, Trubner, and Co., 1S94.) 

 Two years ago Mr. J. J. Aubertin, having seen a copy of 

 N.\TURE for October 13, 1892, containing a letter on the 

 then coming solar eclipse, went home and dreamed a 

 dream. In his vision the Sun visited him and ordered 

 him to gird up his loins, and go to the desert of .Atacama 

 and watch the eclipse. This brief explanation is necessary 

 in order to account for the rather clumsy title of the book 

 before us. Mr. Aubertin, regardless of the belief that 

 dreams should be reversed, and that he was seventy-five 

 years of age, travelled to Chile, and, meeting Prof. 

 Schaeberle there, became one of the eclipse party. He 

 was, however, more an interested layman than a scientific 

 observer, and therefore his book is of very little value 

 to astronomers. In fact, the book is chiefly taken up 

 with tittle-tattle of interest to very few beyond the parties 

 concerned. A picture of the corona, as seen by the 

 author, is very pretty, and compares favourably with the 

 impressions recorded by observers of the phenomena 

 before photography monopolised the field as a coronal 

 artist. But at the present time, the results of visual ob- 

 servations of the corona are regarded with suspicion, and 

 rightly, for they never afford any very definite information 

 as to the true form and structure of the sun's surround- 

 ings. However, Mr. Aubertin faithfully records what he 

 saw, so his observation must be accepted. The book 

 contains Prof. Schaeberle's photograph as a frontispiece. 

 /\eise nach Siidindien. Von Emil Schmidt. Mit 39 

 Abbildungen im Text. (Leipzig : Wilhelm Engelmann, 

 1894.) 

 Herr Sch.MIDT's book is a plain, straightforward narra- 

 tive of a tour through Southern India, in the course of 

 which he visited Madras, Travancore, made an excursion 

 to Cape Comorin, proceeded by Trivandrum to Cochin, 

 and thence by Coimbatore to the Anamalay Hills, going 

 afterwards to the Nilgiris, and finishing at Calicut. The 

 object of the journey was mainly to study the native 

 peoples, and numerous ethnological photographs give a 

 certain value to the book. There is, however, nothing 

 new in the way of an important contribution to science 

 in the work, which is most interesting as showing the 

 impressions produced on an intelligent and observant 

 German by a visit to Southern India. The style is lively, 

 but perfectly serious, and cannot fail to be of nnjch value 

 ' in Germany, where it appears few books have been pub- 



