LITERARY NOTICES. 



561 



value from the practical point of view, while 

 the scientific aspect of the subject can not 

 fail to interest and stimulate the intelligent 

 reader. 



Physics, Advanced Course. By George F. 

 Barker. New York : Henry Holt & Co., 

 1892. Pp. 902. Teacher's price, $3.50. 



One of the most obvious and radical 

 changes wrought by modern investigation in 

 the science of physics is the greater impor- 

 tance which the phenomena of energy have 

 assumed. Until comparatively recent times 

 matter was considered the far more essential 

 factor, and received a considerably larger 

 share of attention. The reverse is now the 

 case, and, as Prof. Barker well says, " The 

 physics of to-day is distinctively the science 

 of energy. Henceforth every physical change 

 must be regarded as conditioned upon the 

 transference or the transformation of energy. 

 Hence, the classification which has been 

 adopted in the present work is based on the 

 most recent views of energy, considered as 

 being ultimately a phenomenon of the ether." 



The introductory portion of this book deals 

 with the general physical relations and the 

 laws of motion. Energy is next treated of 

 as a mass condition, and work as the trans- 

 ference or transformation of energy. Poten- 

 tial is considered as a consequence of mass 

 attraction. Matter is then treated of with 

 reference to the modern views of its struc- 

 ture. Heat comes next, under the head of 

 molecular physics. The remainder of the 

 work is devoted to the phenomena of the 

 ether, which are classified as follows : ether 

 vibration or radiation ; ether stress or elec- 

 trostatics ; ether vortices or magnetism ; and 

 ether flow or electrokinetics. The metric 

 system is used throughout. What illustra- 

 tions there are are well placed, but they are 

 not as numerous as might be wished. There 

 is a detailed table of contents, and a useful 

 index. 



The book is not, like many scientific 

 works, an encyclopasdia, nor is it, as some of 

 the others are, a purely theoretical treatise. It 

 combines very happily the important experi- 

 mental facts of the science with the more 

 probable theory or theories based upon their 

 consideration. It fully justifies Prof. Bar- 

 ker's reputation as a thorough scientist. It 

 is written in a plain and lucid style, and is 

 vol. xlii. — 37 



very readable. The author's treatment of 

 the subject varies somewhat from that of the 

 old standards, but it is a treatment which 

 recent work has been increasingly leadiDg up 

 to, and, in fact, making necessary. 



The old text-books, notwithstanding fre- 

 quent revisions, are unsatisfactory, and a new 

 book, not only embodying the results of the 

 most recent investigations, but also applying 

 these results in the treatment of the subject 

 as a whole, has been a growing necessity. 

 Prof. Barker has given us just such a book, 

 and it is fortunate that so careful and thor- 

 oughly equipped an author was at hand. 



Manners and Monuments of Prehistoric 

 Peoples. By the Marquis de Nadaillac. 

 Translated by N. D'Anvers. New York : 

 G. P. Putnam's Sons. Pp. 412. Price, 

 $3. 



Ant one who wishes to have a handsome 

 volume, fully illustrated, and giving a re- 

 markably interesting account of the discov- 

 eries that have been made in regard to the 

 peoples that lived before any mode of writ- 

 ing was invented, should get this work of De 

 Nadaillac. The author begins with a gen- 

 eral sketch of the stone age, in which he 

 shows that its duration and its place in time 

 can not be set off by any hard-and-fast 

 bounds. He then proceeds to tell what has 

 been learned as to the food of early man, 

 which involves the subjects of prehistoric 

 hunting, fishing, and cannibalism. The au- 

 thor names the horse, the aurochs, the stag, 

 the reindeer, and other animals as furnishing 

 food for the ancient men of Europe, and he 

 names place after place where human bones, 

 charred, and all those containing marrow 

 broken, just as the bones of the lower ani- 

 mals were treated, give evidence of canni- 

 balism. In rapid succession he touches upon 

 the numerousness of animals in the stone 

 age, the weapons used by man in killing 

 them, the implements used in fishing, and 

 various early efforts at navigation. Taking 

 up weapons, pottery, and other articles of 

 use or ornament more in detail, he describes 

 implements from the caves of France, the 

 river valleys of America, and from Eng- 

 land, Italy, Spain, Algeria, and Hindostan. 

 He speaks of pottery from Germany, Italy, 

 France, Belgium, and other countries. This 

 leads to a few words on the ancient use of 

 fire, after which come descriptions of orna- 



