NATURE 



21 I 



THURSDAY, APRIL 21, 1910. 



THE CORRESPOXDEXCE OF OLBERS AND 

 GAUSS. 



V.'ilhelm Olbcrs, sein Lcbcii und sci)ic Werke. Im 

 Auftrage der Nac'nkommen herausgegeben von 

 Dr. C. Schilling. Zweiler Band, Briefwechsel 

 zwischen Olbers und Gauss, Zweite Abtheilung. 

 Pp. vi + 75S. (Berlin : J. Springer, 1909.) Price 

 16 marks, 



TEX vears have elapsed since the first part of this 

 volume appeared (Nature, vol. lxi.,p. 486), the 

 editor having been prevented by other occupations 

 from completing his work, until he secured the co- 

 operation of Dr. Kramer. The present part (or rather 

 volume) comprises Hhe years from 1820 to the death 

 of Olbers in 1840. Although it forms part of a pub- 

 lication intended to keep alive the memory of Olbers, 

 the real hero of this volume is Gauss, not only because 

 he was a greater man than his correspondent, but 

 also because the scientific work of Olbers was almost 

 finished before 1820. All the same, the volume serves 

 to complete the picture of the charming personality 

 of Olbers with which previously published letters had 

 supplied us, while it almost forms a diary of the 

 scientific work of Gauss during the years 1820-40. 



At the beginning of 1820 the new transit circle by 

 Reichenbach had just been mounted at the Gottingen 

 Observatory, and Gauss was busy studying what was 

 practically a new form of instrument. Though he 

 was very fond of observing, the Gottingen Observa- 

 tory did not accomplish as much as might have been 

 expected, considering the devotion of the director to 

 astronomy and the fine instruments at his disposal. 

 This was partly caused by the various other pieces 

 of work in practical science which occupied so much 

 of his time, partly by his never having an assistant 

 until the death of Harding (in 1834), who held a 

 rather anomalous position. Geodetic work soon came 

 10 occupy most of Gauss's time. The continuation of 

 the Danish survey southward through Hanover was 

 finally decided on in 1820, and the work in the field 

 was carried out during the summers of the next five 

 years, most of it by Gauss himself, who, both on this 

 and on the computation of the results, spent a vast 

 amount of time. One cannot help regretting that so 

 great a mathematician should have been obliged or 

 found it necessary to do so much routine work him- 

 self instead of merely supervising its execution by 

 others. No doubt this work gave rise to several 

 theoretical investigations of great value, and occa- 

 sioned the invention of the heliograph by Gauss, but 

 these results would have been produced equally well 

 by his brain if the fatiguing work in the field and 

 the arithmetical drudgery at home had been done for 

 him. Attempts were repeatedly made at Berlin, 

 especially in 1824, to get a post created for Gauss in 

 connection with the Academy of Sciences, but they 

 were never successful. At Berlin he would have been 

 relieved of all teaching work, which he greatly dis- 

 liked, and his time would have been almost altogether 

 his own. The work on the survey continued to drag 

 NO. 21 12. VOL. 83] 



on; the present volume gives full details about the 

 various stages of it, but everything of permanent 

 interest has already been given in excerpts from these 

 letters in Gauss's collected works. 



During the second half of the period in question 

 Gauss devoted himself chiefly to researches on terres- 

 trial magnetism, and continued to keep Olbers posted 

 on the progress of this work. Naturally the electro- 

 magnetic telegraph which was established in 1833 

 between the observ'atory, the Johannisthurm, and the 

 physical laboratory, a distance of several thousand 

 yards, is described with pride and in full anticipation 

 of the great possibilities of the invention. The 

 cooperation of Gauss and Weber in the magnetic 

 work came to an end in 1837, when Weber, as one 

 of the seven professors who had protested against the 

 King's violation of the constitution, had to leave 

 Gottingen. In his letters, Gauss expresses himself 

 with great caution about this unpleasant affair, be- 

 cause, as he says himself, it was not at all unlikely 

 that letters were tampered with while they were on 

 the way. 



Though Olbers in his letters had no great investi- 

 gations to describe to his friend, he had always some- 

 thing of interest to say about the current scientific 

 events of the day. It is interesting to see him occa- 

 sionally give his opinion about some of his contem- 

 poraries. Thus he considered W. Herschel " a good 

 mathematical head, but too much wanting as regards 

 scientific education, though his, so to say, natural 

 mathematics generally guided him in the right direc- 

 tion." As to Schroter, Olbers thought that though Mad- 

 ler had spoken rather too severely of him, he certainly 

 had very exaggerated ideas as to what his telescopes 

 could show, and believed that no one but Herschel 

 could verify what he himself saw or imagined he saw. 



As a sort of running commentary on the progress 

 of astronomy, Olbers 's letters are of great interest, 

 but their value to most readers would have been much 

 increased if the editors had been more liberal with 

 footnotes giving references to astronomical literature. 

 Thus, when Gauss sets forth his grave doubts as to 

 the alleged fraud of d'Angos, it should have been 

 stated that Gauss much later wrote a short paper on 

 this subject, which was printed after his death; also 

 that the researches of d 'Arrest and Gylden have 

 rendered it at least extremely doubtful whether any 

 fraud had been committed. Similarly, when Olbers 

 assumes it to have been proved that Hell falsified his 

 observations of the transit of Venus, it should have 

 been pointed out that Newcomb most thoroughly 

 established Hell's innocence. The nebula mentioned 

 on p. 43 is N.G.C. 7293, and the mysterious nebula of 

 Cacciatore (p. 461) is N.G.C. 6541, as to which J. 

 Herschel showed long ago that Cacciatore had 

 simply made a blunder in identifying a star (Gen. 

 Cat., p. 37). 



This correspondence fills two stout volumes in large 

 octavo, 1500 pages in all. Is it really worth while to 

 print every single word that a great man puts on 

 paper? It is natural that a man should tell his inti- 

 mate friend at some length that his wife and children 

 have measles, or repeatedly give vent to his sorrow 

 and indignation at the conduct of a good-for-nothing 



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