854 



THE POPULAR SCIENCE MONTHLY 



library of every American consul, and the 

 purchase of a sufficient number of copies to 

 supply those officers would be a very proper 

 transaction on the part of the State De- 

 pai'tment. 



The New Astronomy. By Samuel Pier- 

 PONT Langley, Ph. D., LL. D. Illus- 

 trated. Boston : Ticknor & Co. Pp. 

 260. Price, $5. 



Readers of the " Century " magazine 

 will {:ivc this handsome volume a cordial 

 welcome without the formality of an intro- 

 duction, lor the chapters of which it is com- 

 posed have appeared from time to time as 

 illustrated articles in that periodical. Those 

 who are not already acquainted with the 

 fascinating style in which the author depicts 

 the wonders of modern astronomy will de- 

 rive even more pleasure from the book. In 

 explanation of his title, " The New Astron- 

 omy," Professor Langley says that until very 

 lately the prime object of astronomy has 

 been " to say wher? any heavenly body is, 

 and not lehat it is," but that, within a com- 

 paratively few years, a new branch of the 

 science has arisen, " which studies sun, 

 moon, and stars for what they are in them- 

 selves and in relation to ourselves." This 

 branch of astronomy, sometimes called ce- 

 lestial physics, deals with the constitution, 

 condition, and configuration of the sun, 

 moon, and planets ; of meteors, comets, 

 and stars. The view of this field which 

 Professor Langley gives is general rather 

 than detailed, for his book is not addressed 

 to the professional reader, but is intended 

 to solicit for the " new " astronomy the in- 

 terest and support of the educated public. 

 It is admirably adapted to produce this 

 effect. Its descriptions arc picturesque 

 without bending the lines of fact, and its 

 language is vivid without being inaccu- 

 rate. Ninety-three figures, many of them 

 of full - page size, embellish the volume, 

 and the paper, printing, and design of the 

 cover are of the handsomest. Four of the 

 eight chapters of the work are devoted to 

 the sun. The author takes up first the 

 spots on the sun, those immense blotches 

 sometimes exceeding in extent the whole 

 surface of our globe, and tells what is 

 known as to their cause. He regards as 

 not proved the idea that sun-spots have an 

 influence on the weather, thereby affecting 



harvests on the earth, but a connection be- 

 tween the spots and terrestrial magnetic dis- 

 turbances he deems sufficiently established. 

 The sun's corona, as seen in eclipses, and 

 the solar prominences are next described. 

 In the two chapters on the sun's energy 

 some idea of the quantity of heat radiated 

 from the sun is given, and the question of 

 how the solar fire is fed is discussed. The 

 absolute dependence of all activity and life 

 on earth upon the supply of heat received 

 from the sun is pointed out, and the idea of 

 a greater need for utilizing this heat in the 

 future by means of solar engines is sug- 

 gested. Of the planets, Saturn, Jupiter, 

 and Mars are selected for special attention. 

 The moon is described with gratifying full- 

 ness, and an excellent idea of its surface is 

 given by the reproductions of lunar photo- 

 graphs, and of photographs of volcanic for- 

 mations on the earth, and of other wrinkled 

 and cracked surfaces, which are inserted for 

 comparison. The phenomena of meteors and 

 comets are presented in the same enthusi- 

 astic style which characterizes the rest of 

 the book. The concluding chapter embodies 

 some of the results of the application of the 

 spectroscojje to stellar research. The vol- 

 ume is an admirable one for the library of 

 the cultured general reader, for it gives in- 

 formation without an array of figures which 

 are as wearying to everybody but specialists 

 as they are interesting to that class ; it pre- 

 sents conceptions of the vast magnitudes, 

 distances, and forces of the visible uni- 

 verse in the form in which they can be 

 best grasped ; and while it inspires a re- 

 spect for the great results which have been 

 accomplished by the genius and industry of 

 modern astronomers, it also conveys a sense 

 of the boundless regions of space beyond 

 tlie range of their instruments, for the pres- 

 ent unknown to earthly intelligence, and, 

 perhaps, forever unknowable. 



Half-Hours wiTn the Stars. By Richard 

 A. Proctor. New York: G. P. Put- 

 nam's Sons. Pp. 39. Price, $2. 

 The above-named edition of Professor 

 Proctor's " Half-Hours " appears with maps 

 and text specially prepared for American 

 students. It is an atlas of twelve maps, 

 showing the position of the principal star- 

 groups throughout the year, with an ex- 

 planation of each map, and an introduction. 



