LITERARY NOTICES. 



415 



paper, giving the results of his observa- 

 tions, and the more valuable, as it is a 

 comparative study of the health-merits 

 of the two localities ; the marked advan- 

 tages being in favor of the Yellowstone 

 Park over the celebrated Swiss valley. 

 The article is most instructive, and the 

 subject one of interest and moment to 

 our people. 



LITERARY NOTICES. 



INTERNATIONAL SCIENTIFIC SERIES, 

 VOLUME L. 



The Common Sense of the Exact Sciences. 

 By William Kingdon Clifford. With 

 One Hundred Illustrations. New York : 

 D. Appleton & Co. Pp. 271. Price, $1.50. 



Professor Clifford was applied to in 

 1871 to prepare a volume for the " Interna- 

 tional Scientific Series." He was asked if 

 he would undertake a book to be entitled 

 "Mathematics for the Non-Mathematical," 

 the object of which should be to find out how 

 far it is possible to go in explaining mathe- 

 matical ideas to persons of intelligence who 

 have had none of the higher mathematical 

 training. This idea had been before pro- 

 posed to several mathematicians, who agreed 

 that nothing could be made of it ; but it was 

 suggested that if anything could be done with 

 it Clifford's was the genius to do it. Pro- 

 fessor Clifford was struck with the idea as 

 novel and interesting, and said he would 

 make a study of it and see what it promised. 

 The result was so favorable that he decided 

 to undertake the book and give such at- 

 tention to it as his slender health and vari- 

 ous pre-engagements would allow. There 

 was but little doubt that the project was 

 eminently suited to the peculiar character- 

 istics of Clifford's mind ; and that the sub- 

 ject was certain to be handled by him with 

 originality and result in a valuable con- 

 tribution to mathematical literature. But 

 it soon became apparent that there was a 

 serious question about the possibility of his 

 accomplishing the task at all, on account 

 of his declining health. He, however, did 

 considerable work on it, but left it in an 

 unfinished and fragmentary condition at his 

 death in 1S79. 



In arranging the plan of the work it 

 was Professor Clifford's intention to treat 



the fundamental conceptions of mathematics 

 in six parts or chapters under the heads of 

 Number, Space, Quantity, Position, Motion, 

 and Mass. Of these six subjects he dealt 

 with but four, dictating the chapters on 

 Number and Space completely, the first por- 

 tion of the chapter on Quantity, and nearly 

 the entire chapter on Motion. Shortly be- 

 fore his death he expressed a wish that the 

 book should only be published after very 

 careful revision ; that the title, The First 

 Principles of the Mathematical Sciences ex- 

 plained to the Non-Mathematical, should be 

 abandoned, and that the volume should be 

 entitled The Common Sense of the Exact 

 Sciences. 



It was not easy to find a mathematician 

 who would undertake to finish Professor 

 Clifford's work. Upon his death, Professor 

 Rowe, of University College, engaged to do 

 it ; but he also died before accomplishing 

 the task, so that the final revision had to 

 be made by still another hand. There are 

 parts of this work contributed by Professor 

 Clifford which answer finely to the original 

 idea of it, and show what might have been 

 done if he had lived and adhered to the first 

 conception. A mistake was made by the 

 subsequent editors in seeking to finish the 

 work as they thought Clifford would have 

 done it, rather than as in their judgment it 

 might seem best. As it is, the work will 

 probably be found more attractive to mathe- 

 maticians than to non-mathematicians. 



Annals of the Astronomical Odservatory 

 of Harvard College. Vol. XIV. Parts 

 I and II. Observations with the Merid- 

 ian Photometer during the Years 1879- 

 '82. By Edward C. Pickering, Director, 

 aided by Arthur Searle and Oliver C. 

 Wendell. Cambridge : John Wilson & 

 Son, University Press. 1885. 



Almost the earliest record we have of 

 astronomical observation is the catalogue of 

 1 ,028 fixed stars in the " Almagest " of Ptole- 

 my, the epoch of which is a. d. 138. The chief 

 value of this catalogue consists in its clas- 

 sification of the stars into six magnitudes, 

 which classification, so far as those stars 

 which are visible to the naked eye are con- 

 cerned, has been continued to the present 

 day. Since that time many other astrono- 

 mers have made systematic observations on 

 the relative brightness of the stars, the 



