Ukcembeb 16, 1904.] 



SCIENCE. 



837 



the genius of the language. In view of these 

 restrictions, the translation seems good, but 

 of course, other things being equal, preference 

 will be given to the original. 



A few points of detail may be mentioned: 

 Page 9, lines 3 and 4 should read : ' . . . dass 

 er auch fiir a ;^= a + 1 gilt, wenn er fiir 

 a^a richtig ist.' Lines 8 and 9 analogously. 



Page 91, the essential phrase, ' ce qui est 

 experience, ce qui est raisonnement mathe- 

 matique ' (p. Ill of original) has not been 

 translated. 



Page 92, line 2, read ' ist ' instead of ' ware.' 



The original, pp. 31 et seq., ascribes to 

 Kronecker that definition of number (as a 

 partition of all rational number into two sets) 

 which is commonly known as Dedekind's. The 

 translation renders all these passages imper- 

 sonally, and a note calls the presentation of 

 the text Dedekind's, as modified by Tannery. 



The notes ^dded to the translation have de- 

 cided value of their own, and make it desirable 

 either to own both editions or on their account 

 to give the translation the preference. They 

 are to a considerable extent bibliographic, giv- 

 ing excellent lists of references to other works, 

 many of them classic, on the numerous topics 

 which come up. In this respect alone, the 

 notes constitute a welcome and useful supple- 

 ment to the original work, which makes cita- 

 tions only in the most general way with 

 almost no specific references. But they also 

 develop in many instances mathematical 

 treatment of points touched on in the original, 

 which contains practically no such matter. 

 Frequently the notes state briefly the views of 

 others on the topic in hand, or sketch its his- 

 torical development, usually with detailed 

 references. 



A good index and a fuller table of contents 

 have been added in the German edition. 



J. W. A. Young. 



The UNn'EBSiTY of Chicago, 

 October 17, 1904. 



THE NEW SEISJIOLOGY.* 



In the old seismology the only earthquake 

 tremors studied were those of sensible magni- 



* ' Earthquakes in the Light of the New Seis- 

 mology,' by Clarence Edward Dutton, Major U. 



tude, and the records related chiefly to de- 

 structive effects. The earliest philosophy of 

 the subject regardbd the tremor chiefly as a 

 cause, ascribing to it various geologic results, 

 such as the uplifting of coasts and the erup- 

 tion of volcanoes; and only by slow degrees 

 did it come to be recognized as an effect, the 

 jar communicated by subterranean rending. 

 The new seismology employs instruments of 

 the most delicate and sensitive character, and 

 by their aid not only detects tremors far too 

 faint for direct perception, but imdertakes to 

 measure in absolute terms the amplitude, 

 period and speed of the waves- and the in- 

 tensity of the shocks. Its analysis discrim- 

 inates earth waves of four different kinds, 

 classifies shocks according to origin as vol- 

 canic or tectonic, and by means of its data 

 discusses the physical condition of the earth's 

 interior. In a volume recently issued Dutton 

 sets forth the present condition of the science, 

 sketching its history in outline, describing its 

 instruments and characterizing its progress 

 toward the solution of its more important prob- 

 lems. The treatise is well balanced, compact 

 and as comprehensive as consists with adapta- 

 tion to the needs of the general reader. Tech- 

 nicalities are avoided so far as practicable, 

 and details are introduced only for the pur- 

 pose of illustrating principles. While it does 

 not neglect that aspect of the subject which 

 falls within the domain of mechanics, and 

 properly gives a major share of space to the 

 treatment of tremors as elastic waves, it is 

 especially strong in its discussion of the bear- 

 ing of seismology on geophysics. Fortunately 

 for the geologic as well as the general reader, 

 the author brought to his task not only the 

 experience acquired in monographing the 

 Charleston earthquake, but the mental equip- 

 ment resulting from prolonged study of vol- 

 canism and the greater problems of the inner 

 earth. 



The discovered blemishes of the book consist 

 of occasional lapses, either of statement or of 

 correlation between text and illustration. For 

 example, the symbol a (page 175), which 

 stands for the intensity of a shock at unit 



S. A. [No. 14 of The Science Series.] New York, 

 G-. P. Putman's Sons; London, John Murray, 1904. 



