NATURE 



[June 12, 1913 



the examples are of a numerical type. In our 

 opinion, a text-book such as this is more useful 

 to the teacher than the student ; we are inclined 

 to think that it is too diffuse for the latter, but 

 it contains so much that is suggestive and stimula- 

 ting; that few teachers would not gain from using 

 it to supplement and guide their class-work. A 

 good feature of the book is the inclusion of descrip- 

 tions of calipers, verniers, diagonal and plain 

 scales, the micrometer screw-gauge, the sphero- 

 meter, the planimeter and opisometer, methods of 

 measurement of volumes, the construction and use 

 of a scale of chords, and Simpson's method for 

 evaluating areas. There is also an appendix on 

 the use of duodecimals. 



(4) The author writes primarily for medical 

 students, but there is no reason why his work 

 should not be equally suitable for any student of 

 elementary physics ; very small demands are made 

 on the mathematical capacity of the reader. The 

 fundamental results are established at such length, 

 and so clearly, that they should be intelligible to 

 all. Great importance is attached to the use and 

 meaning of algebraic signs ; as soon as this idea 

 is grasped, the formula; employed assume simple 

 forms. The text-book is purposely practical rather 

 than academic ; there is, for example, little mention 

 of the general mathematical theory of systems of 

 lenses or properties of the paths of rays in hetero- 

 geneous media. But the author supplies an abund- 

 ance of excellent illustrations and exercises which 

 will give the student a far better grasp of the 

 principles of the subject than he would gain from 

 an abstract mathematical treatise. 



(5) This collection of about 270 problems (many 

 of which contain several parts), selected from 

 recent French examination papers, is divided into 

 twelve sections : integration, multiple integrals, 

 analytic functions and curvilinear integrals, differ- 

 ential equations, plane curves, skew curves and 

 surfaces, asymptotic lines and lines of curvature, 

 ruled surfaces, partial differential equations, geo- 

 metrical applications of partial differential equa- 

 tions, total differentials, elliptic functions. The 

 statement of the problems occupies one-seventh 

 of the book ; the rest is devoted to their solution. 

 Where we have tested them we have found them 

 sufficiently clear and detailed for any student of 

 average ability. We have no hesitation in saying 

 that this collection will be of real value to students 

 and teachers alike ; and its utility will be still 

 I uither increased if the publishers are able to issue 

 the problems in a separate volume. 



(6) These lectures, which were published a few 

 years ago, are now re-issued with a few notes and 

 corrections. Pressure of other work has prevented 



NO. 2276, VOL. qi] 



the author from attempting to re-write them in' 

 the light of the very considerable progress that 

 has been made in the last six years, but the addi- 

 tion of numerous bibliographical references will 

 enable the reader, if inclined, to see what has been 

 done. In a comparatively small compass the 

 author covers a wide range of theory. In dealing 

 with the bearing of the theory of differential equa- 

 tions upon physical problems, he investigates the 

 elliptic, hyperbolic, and parabolic types with a view 

 to the interpretation and application of the many- 

 valued form of solution and the relation to multiply- 

 connected domains. 



OUR BOOKSHELF. 

 Myths oj the Modocs. By Jeremiah Curtin. Pp. 



xii + 389. (London: Sampson Low, Marston 



and Co., Ltd., n.d.) Price 125. 6d. net. 

 "The value of Indian myths lies in the fact that 

 they represent the mental labour of men who lived 

 ages before those who recorded their thoughts on 

 papyrus, baked brick, or burnt cylinder " (p. 383). 

 The author has supplied us with a valuable set of 

 documents embodying the floating traditions of 

 the Modocs, whose country lies on the borders of 

 Oregon and California. " Man does not appear 

 in any of these myths " (p. 383). In their non- 

 human and non-moral elements the myths belong- 

 to the same stratum as the oldest Irish and Welsh 

 tales, which are generally admitted to be pre- 

 Celtic. In his too brief notes on the myths the 

 author is evidently impressed with their obvious 

 astronomical significance. The first he records 

 "is evidently a sun myth." Mr. Curtin obtained 

 the bulk of his information from " the oldest 

 woman of the Klamath-Modoc tribe of Indians," 

 and from one who, in the prime of his life, was 

 chief of his people. 



It is certain that if the witnesses were cross- 

 examined on their astronomical knowledge, the 

 astronomical significance of the myths would have 

 appeared much clearer than it is found in the book. 

 A golden opportunity has been missed. In one 

 case the astronomical key was simply thrown 

 into the author's hand. The myth of the "Star 

 Brothers " ends as follows : 



" ' You and your brother will no longer be per- 

 sons ; you will be stars, and between summer and 

 winter your people will fight over you. ' 



"The younger boy was at the edge of the sky- 

 when the old man's spirit said: ' You will be a 

 star.' Rii^ht away he was one. As soon as the 

 elder boy reached the edge of the sky he became 

 a star too. 



"Note. — These two stars appear early in the 

 morning toward the end of winter. They are the 

 heralds of spring- " (p. 117). 



It is practically certain that the author's in- 

 formant could have pointed out the " Star 

 Brothers." What we have given us is the very 

 basis of the astronomical interpretation of myths 

 and monuments. Johx Griffith. 



