18 



sciujsrcu. 



[Vol. IX., No. 305 



the witches their scent or the means of indentify- 

 ing them. The savage who refuses to allow his 

 picture to be taken, and the felon who objects to 

 having his 'mug' adorn the walls of Rogues's 

 gallery, are not so far apart, if we can bring our 

 minds to identify the devil of the former with 

 the detective of the latter. O. T. Mason. 



PROFESSOR NEWBERRY ON EARTH- 

 QUAKES. 



Peofessoe Newbeeey's paper on earthquakes 

 is, in the words of the author, "a brief review of 

 what is known and believed in regard to the 

 phenomena and causes of earthquakes by those 

 whose opinions on this subject are most worthy 

 of confidence." After defining the word ' earth- 

 quake,' he proceeds to give a summary of the 

 facts upon which he bases his definition, carefully 

 elaborating and illustrating the subject from the 

 point of view of a cooling and contracting sphere, 

 with a relatively thin crust, and fluid or viscous 

 interior. The latter part of the essay is treated 

 under the headings, ' Earthquakes and volcanoes 

 as measures of the thickness of the earth's crust,' 

 and ' Flexibility of the earth's crust.' Finally, 

 ' Proximate causes of earthquakes ' are briefly 

 considered, and a short bibliography is appended. 



The definition, which is taken as the text, and 

 which is really an epitome of the whole argu- 

 ment, is as follows : " An earthquake is a move- 

 ment caused by a shrinking from the loss of heat 

 of the heated interior of the earth, and the crush- 

 ing-together and displacement of the rigid exterior 

 as it accommodates itself to the contracting nu- 

 cleus." It is then stated that the facts upon 

 which this statement is based are so numerous 

 and significant that the conclusion ' is not only 

 convincing, but inevitable.' Although this broad 

 generalization is perhaps applicable in the case of 

 most earthquakes, and the theory as to the struc- 

 ture of the earth which it involves is very gener- 

 ally accepted by geologists, yet, in view of the 

 fact that many eminent scientific men are not 

 prepared to subscribe to it at all, in either case it 

 is to be regretted that the author has not adopted 

 the comprehensive and more non-committal defi- 

 nition given by Mallet, and substantially repeated 

 as follows by Powell (in The forum for Decem- 

 ber) : " An earthquake is the passage of waves of 

 elastic compression in the crust of the earth.'' 

 The very fact that different theories are to be 

 found, even in the very latest utterances of emi- 

 nent authorities, would seem to make it desirable 

 to acknowledge that the subject is not one that 



Earthquakes. By Prof. J. S. Newbekky. New York, The 

 author, 1886. 8°. 



can be disposed of in such an eoc cathedra state- 

 ment, but rather one worthy of the most pains- 

 taking study, which, indeed, it is now receiving 

 from the most advanced nations. The further 

 statement that "earthquakes are neither novel 

 nor mysterious, but are among the most common 

 and simplest of terrestrial phenomena," is not 

 likely to receive very wide acceptance in its en- 

 tirety, and issue will certainly be taken with Pro- 

 fessor Newberry as to there being any very great 

 degree of unanimity in this opinion among "those 

 whose opinions are most worthy of confidence." 

 Similarly it must be said that far more confi- 

 dence is placed by the author in the various 

 methods of calculating the depth of origin by 

 means of accurate observations as to time and 

 angle of emergence than seems warranted. The 

 problem is so complicated by the great hetero- 

 geneity of the superficial formation of the earth's 

 crust, that the best observations we can make,, 

 give, at best, only roughly approximate results. 

 Again, it is stated that the reported shortening of 

 railroad-tracks in certain places near Charleston, 

 ' ' if verified and measured, would give a clew to 

 the location and extent of the subterranean move- 

 ments which produced the vibrations." Most 

 authorities, however, will probably regard it, in 

 the case of a shock disturbing so great an area, 

 as an entirely secondary effect, along with the 

 production of local sinks, geysers, and land-slides. 

 This well arranged and condensed resume of 

 the subject, from the stand-point of a geologist of 

 Professor Newberry's reputation, cannot fail to 

 be read with interest by the general reader as 

 well as by the special student. The only criticism 

 that can he made, other than favorable, seems to 

 be that to the average reader it may leave the 

 impression that the causes of all earthquakes, and 

 even the nature of the earth's interior, are now so 

 well understood as to leave very little room for 

 difference of opinion among those best qualified 

 to judge. Everett Hayden. 



PHANTASMS OF THE LIVING. 

 This is a most extraordinary work, — fourteen 

 hundred large and closely printed pages by men 

 of the rarest intellectual qualifications, for the 

 purpose of setting on its legs again a belief which 

 the common consent of the ' enlightened ' has 

 long ago relegated to the rubbish-heap of old 

 wives' tales. In any reputable department of 

 science the qualities displayed in these volumes 

 would be reckoned superlatively good. Untiring 

 zeal in collecting facts, and patience in seeking to 



Phantasms of the living. By Edmund Gurnet, Fkedeeic 

 W. H. Myers, and Frank Podmore. 2 vela. London, Triib- 

 ner, 1886. 8°. 



