September 9, 1915] 



NATURE 



31 



The slopes of Pisgah, where Lot is said to have 

 soug^ht refuge in a cave, though they command a 

 view of the Dead Sea, can scarcely have been sub- 

 ject to "volcanic storms of bitumen," which, by 

 the way, is not usually an eruptive product. 

 Whether it is " some thirty thousand years " since 

 the last glacial period in Palestine may or may 

 not be correct, but that was not indicated by the 

 " earth's appearance above the sea," nor was the 

 former unfit for men to live upon until " some five 

 or six thousand years ago." "Sandstone, lime- 

 stone and chalk," should probably be read "and 

 shale," for chalk, in the strict sense of the word, 

 is not found in Palestine. To say that the Jordan 

 valley is not due to a " rift cut down into the rock 

 by a flowing stream," but " to the original folding 

 of the earth's crust," is both vague and in- 

 accurate, and the peculiar physical features of the 

 Kishon valley, which indirectly have so often made 

 it a battlefield of nations, hardly receive even a 

 passing notice. No doubt "geologically Pales- 

 tine is a most interesting country with which to 

 become acquainted," but we fear that this book 

 will not do much to bring about so desirable a 

 result. 



OVR BOOKSHELF. 



The Science of Mechanics : a Critical and His- 

 torical Account of its Development. By Prof. 

 E. Mach. Supplement to the third English 

 edition containing the author's additions to the 

 seventh German edition. Translated and anno- 

 tated by P. E. B. Jourdain. Pp. xiv+io6. 

 (Chicago and London : The Open Court Pub- 

 lishing Co., 191 5.) Price 2S. 6d. net. 

 Mach completed the first edition of "The Science 

 of Mechanics " at Prague in 1883. An English 

 translation (by McCormack) appeared just ten 

 years later, and of this two further editions 

 embodying the alterations made in the successive 

 German editions have been published. 



With the seventh German edition (Leipzig, 



[2), however, the alterations made were much 



>re numerous and important ; and the present 



lume, which forms a supplement to the third 



iglish edition (1907), contains a full account of 



;m, together with some pages of notes due to 



translator. It is remarkable that notwith- 



inding the thirty years which separate the first 



id seventh editions, Prof. Mach finds himself 



>le to strike identically the same note in his new 



)nclusi6n " as he had done in the preface to the 



»t edition. In that preface he undertook that 



[echanics will here be treated, not' as a branch 



mathematics, but as one of the physical 



iences " ; whilst in a concluding passage in the 



jsent volume he points out that "the doctrines 



mechanics have developed out of the collected 



)eriences of handicraft by an intellectual pro- 



js of refinement ... we see that the savage 



:overies of bow and arrows, of the sling, and 



NO. 2393, VOL. 96] 



of the javelin, set up the most important law of 

 modern dynamics — the law of inertia — long before 

 it was misunderstood with thoroughgoing per- 

 versity by Aristotle and his learned commenta- 

 tors." 



Mach speculates much as to the validity of the 

 conceptions of absolute space and time, and on 

 the effect of using as a reference system the 

 " fixed " stars. What would have been the conse- 

 quence had there existed a sufficiency of cosmic 

 dust to render the stars invisible to an observer 

 on the earth? In Mach's opinion the "surround- 

 ings in which we live, with their almost constant 

 angles of direction to the fixed stars, appear to 

 me to be an extremely special case, and I would 

 not dare to conclude from this case to a very 

 different one." 



It is to be hoped that no library which possesses 

 the third English edition will be without this 

 companion volume. 



Report on the Building and Ornamental Stones 

 of Canada. Vol. ii.. Maritime Provinces. By 

 Dr. Wm. A. Parks. Pp. xii + 264. Plates i- 

 xlv, sketch maps 1-9. (Ottawa : Government 

 Printing Bureau, 1914.) 

 This volume constitutes the third part of the 

 monograph on the building and ornamental stones 

 of Canada, and worthily upholds the high standard 

 established in the earlier portion of the work. 

 The greater part of this report is occupied by a 

 systematic account of the quarries of the maritime 

 provinces and of their products. The stones are 

 considered according to the class to which they 

 belong, e.g., granite, black granite (greenstones), 

 sandstone, limestone, &c. , and arranged according 

 to more or less definite geographical areas into 

 which the quarries naturally fall. In order to 

 give prominence to the economic and commercial 

 aspect of the work, the quarries are described 

 under the name of the owner wherever possible. 

 The general plan adopted for the description of 

 individual properties is : (a) quarry observations ; 

 (b) description of the stone, with tests ; (c) 

 economic remarks and statistics ; (d) examples of 

 the use of the stone. Sketch maps are given 

 showing the geology and location of quarries in 

 important districts ; special mention must be made 

 of the excellent colour-photo plates which show in 

 an admirable manner the colour and appearance 

 of the stones, a feature which should be appre- 

 ciated by architects. 



The Canadian Department of Mines is to be 

 congratulated on the wisdom of undertaking a 

 comprehensive and businesslike statement of the 

 country's quarry resources, and not least, for 

 carrying out a series of systematic tests on the 

 quarry products. Whatever opinion may be held 

 as to the value of such tests, there can be no 

 doubt that when they are made under uniform 

 conditions, and as nearly as possible at one time, 

 their utility is enormously increased. The 

 existence of this monograph should result in a 

 great saving of time, energy, and money on the 

 part of all users of stone in the Dominion. 



J. A. H. 



