624 



SCIENCE. 



[Vol.. II., No. 40. 



of the stars met with, and the struggles they passed 

 through to overcome them, whereby a human inter- 

 est is given to the study of their work; and secondly, 

 by clearly indicating the nature of the problems to 

 be solved by the science." 



In point of fact, however, the. book does 

 much more than this : it presents a clear, con- 

 nected, readable account of the chief steps in 

 the progress of astronomj^ from the earliest 

 times to the present day ; and while the lives 

 of the astronomers, judiciously' inserted and 

 as a rule well told, greatlj' heighten the in- 

 terest of the story of the science, the reader 

 alwaj's feels that they are only the accidents 

 of the book, while the unfolding of the suc- 

 cessiA'e triumphs of astronomy-, and the esj)o- 

 sition of its laws, objects, and methods, is its 

 constant purpose. 



Interesting and readable as the book is 

 almost throughout, we nevertheless think the 

 author mistaken in regarding it as well adapted 

 to serve as an introduction to astronomy for 

 non-mathematical readers. It is true that 

 onlj' verj' elementarj- mathematics is explicitlj' 

 introduced ; but few readers who are not 

 either equipped wMth the habits of thought 

 bred by mathematical study, or possessed of 

 some familiaritj- with the outlines of astron- 

 omy, can follow intelligently and with inter- 

 est the discussion of complicated motions. 

 To young people who have gone through an 

 elementary course in astrouomj-, on the other 

 hand, the book before us will be most instruc- 

 tive and stimulating. The subject is vivified, 

 not onlj' by the presentation of the lives, so 

 .full of inspiration, of the great founders of the 

 science, but also bj- a far clearer view of its 

 progressive development than an ordinary text- 

 book can afford. And the impression is not 

 weakened hy the introduction of insignificant 

 details, or of merely statistical information. 

 Not that details are avoided when they are 

 necessary to the exposition or illustration of 

 a great law, or of an important phenomenon : 

 on the contrary, one is surprised at the num- 

 ber and di\'ersit3- of the points which are 

 explained, and in general clearly and satisfac- 

 torily explained. The author has not refrained 

 from giving simple expositions of mechanical 

 and ph3'sical laws when they are essential to 

 the clear understanding of astronomical doc- 

 trines. B}- explaining the laws of motion, for 

 example, and insisting on their fundamental 

 importance, he puts the reader in a position 

 to understand the great problem of physical 

 astronomj-, and to appreciate its solution. In 

 connection with spectrum analysis, a little 

 space devoted to the analog^' between sound 



and light makes the subject clear to the aver- 

 age reader. And many other instances might 

 be mentioned. 



As the character of the book does not make 

 it incumbent upon the author to present any 

 thing like a complete survey of even the most 

 prominent astronomical facts, he is able to give 

 a much fuller exposition of the central points 

 in the theory of astronomy than one would 

 expect to find in so limited a space, and to 

 give intelligible accounts of many things hav- 

 ing a direct connection with these central prin- 

 ciples, which are usually passed over with a 

 bare mention in small works on astronomj-. 

 Thus, more than eight}- pages are devoted to 

 Newton,- onlj' a small portion of which is bio- 

 graphical, a whole chapter of fifty pages being 

 specifically devoted to the Principia. And 

 pretty full accounts are given, for example, 

 of Herschel's theory of stellar distribution, of 

 the nebular hypothesis, of Laplace's proof 

 of the stability of the solar sj-stem and La- 

 grange's previous attempts in that direction, 

 and of the recent researches of Mr. G. H. 

 Darwin. 



It would be quite possible to point out minor 

 defects in the book. There is occasionally 

 (but very seldom) an attempt to explain what 

 cannot be satisfactorily explained in a popular 

 manner ; once in a while the demonstrations, 

 which are usually in excellent and attractive 

 form, are made pedantically stiff; there are a 

 few inaccuracies, chiefl}' of expression ; and 

 th^re are possibly' a few cases of Sunday- 

 school moralizing from insufficient premises. 

 The only instance we have noticed of unfair- 

 ness in the historical portion is in the pas- 

 sage relating to the Mohammedan astronomers. 

 Scant justice is done them ; and the author 

 permits himself to combine silliness with 

 injustice in saying that ' it illustrates the 

 slavish stupiditv of the race,' that a discover}' 

 made bj' an Arab astronomer in the tenth 

 centitr}- was afterwards forgotten by them ! 

 A grave defect, but one which can easilj' be 

 remedied in a new edition, lies in the lack 

 of an index, — an omission which seriously 

 impairs the value of this very interesting and 

 useful work. In conclusion, lest we should 

 lea^■e the impression that the book can be read 

 with advantage onlj- hy students, we would 

 say that the chapters which combine in the 

 highest degree biographical with scientific 

 interest, — those on Copernicus, Tycho Brahe, 

 Kepler, and Galileo, — and many other parts 

 of the book, maj' be read with great pleas- 

 ure and profit by a ver^- wide circle of read- 

 ers. 



