J. C. KAPTEYN VAN MAANEN 561 



oughness and accuracy which could be obtained only by two such 

 masters. If we had no other work from his hand, Kapteyn's name 

 would still take an honorable place in astronomical literature and 

 would be mentioned with those of Argelander, Schonfeld, and 

 Gould, names which every astronomer honors with gratitude. Yet 

 in addition to this we have his discovery of the star streams, his 

 plan of selected areas, his founding of the Groningen Astronomical 

 Laboratory, now called " Astronomical Laboratory Kapteyn," which 

 at the recent meeting of the International Astronomical Union, 

 -Baillaucl duly called one of the three things which in his 50 years 

 of astronomical life had revolutionized his science; and above all 

 we have Kapteyn's investigations on the structure of the universe. 



Truly Kapteyn belonged among the few really great men whose 

 death creates a vacancy which can not be filled. 



It seems superficial to enumerate here the many honors bestowed 

 on him during his life. For completeness, however, we must men- 

 tion them : Kapteyn received the honorary degree of D. Sc. from the 

 Cape of Good Hope ; of D. Sc. from Harvard University ; of LL. D. 

 from Edinburgh; he received the gold medal of the Royal Astro- 

 nomical Society, the Watson and the Bruce medals and the Prix de 

 Pontecoulant; he was chevalier of the Legion of Honor of France, of 

 the Netherlands Lion ; he had the order " Pour le Merite," and was 

 commander in the Dutch order of Oranje-Nassau. Kapteyn was 

 elected a member or associate of the following academies : Royal 

 Astronomical Society, American Philosophical Society, National 

 Academy of Sciences, Imperial Academy of St. Petersburg, Royal 

 Academy of Dublin, Royal Academy of Edinburgh, British Asso- 

 ciation, Royal Swedish Academy, Royal Society of Sciences of 

 Upsala, American Society, the Academy of Sciences in Paris, the 

 Royal Society of London, the Academy of Sciences in Finland, and 

 of the Royal Physical Association in Lund. 



All through his life Kapteyn made friends — when he was young, 

 among the older people; when older, among each new generation 

 with which he came in contact. It was not difficult to become his 

 friend; he saw always the best qualities in every person; the rest 

 did not exist for him. There was always an atmosphere of happi- 

 ness around him, in his daily life as well as in the scientific assem- 

 blies, where he was the center of gravity. His departure will be 

 keenly felt in the astronomical world, but not there alone; many 

 others will mourn the ending of this noble and happy life. 



Especially in America, Kapteyn had numerous friends. From 

 1908 to 1914 he came to this country every summer to spend a few 

 months at the Mount Wilson Observatory, of which institution he 

 was research associate. Kapteyn and Mrs. Kapteyn thoroughly 



