472 SOME NEW BOOKS [june 



larger general works on the subject, but also by studying the chief monographs 

 which have appeared on special periods, and also to some extent the original 

 works of the great men who have guided science into new paths. The book 

 does not suppose the reader to possess any (or at least but a very slight) 

 previous knowledge of astronomy, and accordingly the first chapter, on " Primi- 

 tive Astronomy," describes the celestial sphere and its principal phenomena. In 

 the next chapter, on " Greek Astronomy," the pre-Alexandrian period might per- 

 haps have been more fully dealt with, and here it appears that the author is not 

 so well acquainted with monographs and special studies {e.g. those of Ideler, 

 Schiaparelli, and others) as he generally seems to be. That he confounds 

 Herakleides with Herakleitus is perhaps due to his having depended too much 

 on Wolf. The account of the Alexandrian astronomy is clear and correct, and 

 the same may be said of the following periods. Throughout the author gives 

 a very correct picture of the state of science at the time under consideration, 

 while his book is not only accurate but at the same time extremely readable. 

 The astronomy of the last two hundred years occupies exactly half the volume, 

 and both "gravitational," "observational," and "descriptive" astronomy are 

 passed in review. The two latter departments are perhaps not quite so 

 thoroughly discussed as the first one, and especially it seems strange that next 

 to nothing is said about instruments. The numerous illustrations (including 

 nine excellent portraits) are well chosen, and in many cases borrowed directly 

 from the original works of Copernicus, Galileo, etc. Not only as a University 

 Extension Manual, but also as a book suitable both for the general reader and 

 for the more advanced student, the work deserves every commendation. 



J. L. E. I). 



A TEXT-BOOK OF GENERAL PHYSICS. 



A Text-Book of General Physics for the Use of Colleges and Scientific 

 Schools. By C. S. Hastings, Ph.D., and F. E. Beach, Ph.D. 8vo, 

 pp. viii. + 768, with 495 figs. Boston: Ginn & Co., 1899. Price, 

 2 dollars 95 cents. 



The reputation of the two Yale Professors led us to expect a thoroughly 

 sound and interestingly written text-book on physics ; and our hopes have been 

 to a large extent realised. The book looks well, is finely illustrated, and con- 

 tains some interesting novelties of treatment. How far the introduction of such 

 novelties into an avowedly elementary book is expedient is a matter on which 

 there will probably be great difference of opinion. Again, we very much question 

 the wisdom of giving, necessarily without proof, Clausius' expression for the virial 

 of a gas, evidently as a stepping-stone to an indication of how Van der Waals 

 arrived at his famous equation, which after all is only of limited applicability. 

 The chapter devoted to oboes, clarinets, French horns, saxophones, etc., might 

 with advantage have been omitted, and the space utilised to far better purpose. 

 The arrangement of the book is a little peculiar, and leads to the awkwardness 

 of discussing electro-magnetic waves before waves in general have been taken 

 up. In short, the interpolation of electricity and magnetism between elasticity 

 and sound has nothing to commend it. There is also an unfortunate inversion 

 in discussing magnetic induction and hysteresis before any account is given of 

 electro-magnetism. These faults in arrangement may perhaps be covered by the 

 statement in the preface that "the book as a whole is designed as an aid to the 

 teacher," and "assumes as a necessary complement a course of [experimental] 

 demonstrations." In other respects there is much in the book that is worthy of 

 praise, one interesting feature being the use the authors make of the wave-front 

 in discussing optical theories and applications. Students who have already 

 gained some knowledge of physical facts and theories will find their grip of the 

 subject strengthened by a careful perusal of this text-book, while the teacher 

 will probably receive hints of no small value. C. G. Knott. 



