244 



THE POPULAR SCIENCE MONTHLY. 



which, according to Mr. Cook, did not 

 contain it. 



In an elaborate article entitled " Vir- 

 chow and the Teachings of Science," 

 contributed to the Nineteenth Century 1 

 by Prof. Kingdon Clifford, the great 

 German has received his decisive and 

 annihilating answer. So clean and fin- 

 ished a piece of controversial work we 

 have rarely seen. There is, of course, 

 much in Prof. Virchow's address that 

 is true and. important, but that which 

 gives it celebrity is the avowal, by an 

 eminent biologist, that the doctrine of 

 evolution is not proved. This is at once 

 a question of the nature, extent, and 

 validity of evidence, and Prof. Clifford 

 takes it up as a logician, in a very quiet 

 way, with much delicate humor and a 

 peculiar charm of style, for wdrich he is 

 unrivaled. Prof. Clifford points out the 

 baselessness of Virchow's conclusions in 

 regard to the evidence for the descent of 

 man, and, then passing to the question 

 of education, he not only answers him 

 effectually, but does it in such a manner 

 as to make his paper a very important 

 contribution to educational philosophy. 



LITERARY NOTICES. 



Stargazing : Past and Present. By J. 

 Norman Lockyer, F. R. S. New York : 

 Macmillan&Co. Pp.496. Price, $7.50. 



In this elegant volume Mr. Lockyer gives 

 an excellent popular account of the rise and 

 progress of instrumental astronomy. His 

 work is an admirable illustration of the law 

 of mental evolution by which great results 

 have been attained through prolonged pe- 

 riods by minute increments of improvement. 

 There were, of course, many conspicuous 

 cases in which the science went forward, 

 apparently by strides, as when Hipparchus 

 invented the astrolabe, which led to the 

 discovery of the "precession of the equi- 

 noxes," or when Galileo discovered the iso- 

 chronism or equal-time oscillations of the 

 pendulum, or when Dollond invented aehro- 



1 Reprinted in The Popular Science Sup- 

 plement for May. 



matic lenses for the telescope, or when pho- 

 tography and spectrum analysis were applied 

 to celestial objects. But in all these cases 

 of apparent sudden leaps, there was a pre- 

 vious time of preparation, in which nu- 

 merous failures, or partial but inadequate 

 successes, led up to the matured result. It 

 is interesting to trace in Mr. Lockyer's pages 

 the intimate and absolute dependence of 

 astronomical progress upon the skill of 

 the mechanic in the workshop. The gen- 

 ius of the inventor was always hampered 

 by mechanical difficulties that could only 

 be resolved by the dexterity and ingenuity 

 of machinists and workers in metals, glass, 

 and other materials. The bold speculator 

 could conjecture, and the mathematician 

 could verify, but all had to wait for the pro- 

 ficiency of the practical manipulator. 



Mr. Lockyer opens his book with an ac- 

 count of early star-gazing in the pre-tele- 

 scopic age, which terminates with Tycho 

 Brahe, who died early in the seventeenth 

 century. The second division of his work 

 is devoted to the development of the tele- 

 scope ; the third, to time and space meas- 

 urers ; the fourth, to modern meridional 

 observations with transit-instruments ; the 

 fifth part deals with the equatorial, and the 

 mounting of large telescopes, and modern 

 observatory equipments ; and in the last 

 division of the work, astronomical physics, 

 Mr. Lockyer treats of the chemistry of the 

 stars, spectrum analysis, and photography, 

 applied to the heavenly bodies. His book 

 is elaborately illustrated, and is a useful 

 popular contribution to astronomical liter- 

 ature. 



International Scientific Series, No. 

 XXIII. Studies in Spectrdm Analy- 

 sis. By J. Norman Lockyer, F. R. S. 

 D. Appleton & Co. Pp. 251. 



The name of Mr. Lockyer is eminent in 

 connection with spectrum analysis, and will 

 secure intelligent attention to whatever he 

 writes upon it. But the subject has been 

 so thoroughly sifted and expounded for the 

 last five years, that, in contributing a vol- 

 ume upon it for the International Scientific 

 Series, he had by no means an easy task. 

 Declining to follow in the beaten paths of 

 compilation, and avoiding a mere restate- 

 ment of rudiments, or the detailed treat- 

 ment of systematic treatises like those of 



