July 14, 19 10] 



NATURE 



45 



of astronomers. He was entitled to all the renown 

 which he acquired. For though others may have 

 entertained similar views and expressed them more 

 or le-,s distinctly, they fell short of demonstration. 

 Prof. Kirkwood, for e.\aniple, had put the pertinent 

 question, " May not our periodic meteors be the debris 

 of ancient but now disintegrated comets, whose 

 matter has become distributed around their orbits?" 

 At a moment when we are remembering with grati- 

 tude the eminent services of the distinguished Italian 

 astronomer, there is no necessity to stir old con- 

 troversies; but when so many, from the time of 

 Hallev, have been so near a solution of the puzzle, 

 it mav quicken our appreciation of his genius to 

 remember that he carried the question one step beyond 

 his predecessors, removing it from the grounds of 

 conjecture to the certainty of conviction. In this 

 connection it is not out of place to recall the remark- 

 able series of letters that Schiaparelli addressed to 

 Father .Secchi in 1866, models of close reasoning lead- 

 ing to a successful result. But as is frequently the 

 case when a brilliant discovery is made, it is possible 

 to detect a certain amount of luck contributing' to the 

 final outcome. 



Schiaparelli 's crowning success was the recognition 

 of the similarity of the orbit of the .August meteors 

 with that of the comet of 1862. That this particular 

 comet of long period should have returned to the 

 sun only a few years previously to the discovery, and 

 that its path had been well determined, was a most 

 fortunate circumstance, and one that not only 

 strengthened the evidence of identification, but 

 affected the popular estimate of the certainty of the 

 result. Similarly, with the near coincidence of the 

 return of the comet of 1866 with the great November 

 shower, and less conspicuously that of the 1S61 comet 

 with the April Lyrids, astronomers had the advantage 

 of dealing with trustworthy elements. If these 

 comets had passed through perihelion without being 

 observed an important link would have been wanting 

 in the chain of evidence. .As it is, these earliest cases 

 of identification are the most conspicuous and the 

 surest examples of a relation, as significant as it was 

 unexpected. For his part in the happy result 

 Schiaparelli was deservedly awarded the gold medal of 

 the Roval .Astronomical Society in 1S72. 



In some other directions the work of Schiaparelli 

 has not received the same complete recognition. In 

 1877, when Mars was in a favourable position for 

 observation, he announced the detection of the 

 famous canals which have since been the subject of 

 fierce dispute and controversy. Whether these 

 "canals," interrupting the continental areas, are 

 existent and permanent phenomena has been much 

 questioned ; though the doubts expressed do not relate 

 so much to the existence as to the interpretation that 

 has been placed upon them. Schiaparelli regarded 

 the 'gemination" of the canals as a periodical 

 phenomenon depending on the seasons, and was 

 firmly convinced of their alternate obliteration and 

 reappearance. The only point on which we need insist 

 here is the effect that his industry and acuteness of 

 vision have had on the development of astronomical 

 observation. It has been the means of attracting a 

 vast amount of attention to the planet, has enormously 

 increased the activity of observation, and led to the 

 training of a class of observers, who have taken up 

 the subject of planetary markings with avidity. 

 Schiaparelli has written much on the appearance of 

 Mars, and a very lai;ge literature has collected round 

 this subject, due largely to his initiative. 



.Another subject with which his name will be con- 

 nected is the attempt to derive the times of rotation of 

 Mercury and Venus. Our information on this topic 



is vague, and the data uncertain. Notwithstanding 

 the care bestowed on the observations, and the 

 plausible nature of his deductions, his results have 

 been accepted with some hesitation. From his 

 patient watching, and from the length of time devoted 

 to the study, his conclusion that Mercury turns on 

 its axis in the same time that it revolves' round the 

 sun is entitled to very great consideration. This result 

 was published in 1S82, and it was not until some 

 years later, 1S90, that he declared that Venus behaved 

 in a similar manner to Mercury. The long interval 

 showed that Schiaparelli did not jump to conclusions, 

 and the limits he assigned to the rotation, between 

 six and nine months, prove that he was not inclined 

 to accept a hypothesis, however specious, in fa\our 

 of the results of observation. 



These three conclusions, having reference to the 

 connection of meteors with comets, to the surface 

 markings of Mars, and to the velocity of rotation of 

 the interior planets, are no small achievement in the 

 life of one astronomer. It need not be said that they 

 do not exhaust his scientific activity. A vast amount 

 of routine work, of double-star measurement, and of 

 the position of planets, stands to his credit. He was 

 the author of some 250 papers in various journals, 

 and his memory is as much entitled to our respectful 

 homage for his industrv as for his originalitv. 



\v: E. p. 



PROF. ]. G. GALLE. 

 VY^ITH deep regret we have to announce the death, 

 ** on July 10, at ninety-eight years of age, of 

 the veteran astronomer Prof. J. G. Galle, the doven of 

 the .Associates of the Royal .Astronomical Society, into 

 which body he was elected in 1848. For nianv vears 

 he had been connected with the Berlin Observatory, 

 and will be remembered as the last of the little band 

 of astronomers who were associated in the discovery 

 of Neptune. Galle it was who had the good fortune 

 to carry to complete fruition the successful analyses 

 of .Adams and of Le A'errier. It was his lucky chance 

 to compare Bremiker's map with the sky, to detect 

 the planet, and establish its identity by determining 

 the motion. He long outlived all his companions and 

 associates in that historic scene enacted in the Berlin 

 Ooservatory on September 23, 1846, the antecedents of 

 which have been told so many times that it is un- 

 necessary to refer to them here more particularly. It 

 is more pertinent to recall, as more likelv to have 

 been forgotten, that he was one of the first to have 

 seen the "crape" ring of Saturn. When this dis- 

 covery was announced in 1850, simultaneously by 

 Bond and Dawes, Galle directed attention to some 

 observations he had made twelve years earlier, in 

 J838-9, in which he had actually measured the 

 diameter of this interior dusk}' ring. The observations 

 were communicated at the time to the Berlin 

 .Acadeniy, but Galle did not insist on their import- 

 ance, as he could not persuade himself that the 

 phenomenon was permanent and not due to the eticct 

 of contrast. 



From Berlin, Galle went to Breslau, and there he 

 proposed that method of determining the solar 

 parallax, by observations of small planets, which has 

 since proved so successful. His earliest attempts in 

 this direction were applied to measures of Phocaea, 

 and later, from observations of Flora, he deduced the 

 value of 8'87". This was at a time when astronomers 

 were beginning to discard Encke's value of 8'58" 

 in favour of Le Verrier's 8'95". In another direction 

 it is not possible to overlook a very distinct service 

 which Galle rendered to astronomy. His catalogue 

 of cometarv orbits has long been a standard work 



NO. 2124. VOL. 84] 



