Febeuakt 13, 1920] 



SCIENCE 



151 



by actual examples, however, that this is not 

 the case, and that an important advance, in 

 harmony with Mr. Root's conception, is en- 

 tirely possible. 



It goes without saying that no scheme of 

 organization, effected by lesser men, can ever 

 duplicate the eiwch-making discoveries of the 

 Faradays, the Darwins, the Pasteurs, and the 

 Eayleighs, who have worked largely unaided, 

 and who will continue to open up the chief 

 pathwaj'S of science. Even for such men, 

 however, organization can accomplish much, 

 not by seeking to plan their researches or con- 

 trol their methods, but by securing cooper- 

 ation, if and when it is needed, and by render- 

 ing unnecessary some of the routine work 

 theiy are now forced to perform. 



Let us now turn to some examples of or- 

 ganized research, beginning with a familiar 

 ease drawn from the field of astronomy, where 

 the wide expanse of the heavens and the nat- 

 ural limitations of single observers, and even 

 of the largest observatories, led long ago to 

 cooperative effort. 



In the words of the late Sir David Gill, 

 then Astronomer Royal at the Cape of Good 

 Hope, the great comet of 1882 showed " an 

 astonishing brilliancy as it rose behind the 

 mountains on the east of Table Bay, and 

 seemed in no way diminished in brightness 

 when the sun rose a few minutes afterward. 

 It was only necessary to shade the eye from 

 direct sunlight with a hand at arm's length, 

 to see the comet, with its brilliant white 

 nucleus and dense white, sharply bordered tail 

 of quite half a degree in length." This extra- 

 ordinary phenomenon more brilliant than any 

 comet since 1843 marked the beginning of 

 celestial photography at the Cape of Good 

 Hope. No special photographic telescope was 

 available, but Sir David enlisted the aid of 

 a local photographer, whose camera, strapped 

 to an equatorial telescope, immediately yielded 

 pictures of exceptional value. But even more 

 striking than the image of the comet itself 

 was the dense background of stars simulta- 

 neously registered upon these plates. Stellar 

 photographs had been taken before, but they 

 had shown only a few of the brighter stars, 



and no such demonstration of the boundless 

 possibilities of astronomical photography had 

 ever been encountered. Always alive to new 

 opportunities and keen in the appreciation of 

 new methods. Sir David adopted similar 

 means for the mapping of more than 450,000 

 stars, whose positions were determined through 

 the cooperation of Professor Kapteyn, of 

 Groningen, who measured their images on the 

 photographs. 



Stimulated by this success, the Henry 

 brothers soon adapted photographic methods 

 for star charting at the Paris Observatory, 

 and in 1887 an International Congress, called 

 at Sir David's suggestion, met in Paris to 

 aiTange for a general survey of the entire 

 heavens by photography. Fifty-six delegates 

 of seventeen different nationalities resolved 

 to construct a photographic chart of the whole 

 sky, comprising stars down to the fourteenth 

 magnitude, estimated to be twenty millions in 

 number. A standard form of photographic 

 telescope was adopted for use at eighteen ob- 

 servatories scattered over the globe, with re- 

 sults which have appeared in many volmnes. 

 These contain the measured positions of the 

 stars, and are supplemented by heliogravure 

 enlargements from the plates, estimated, when 

 complete for the entire atlas of the sky, to 

 form a pile thirty feet high and two tons in 

 weight. 



The great cooperative undertaking just de- 

 scribed is one that involves dealing with a 

 task that is too large for a single institution, 

 and therefore calls for a division of labor 

 among a number of participants. It should 

 be remembered, however, that a very different 

 mode of attacking such a problem may be 

 employed. In fact, although the difference 

 between the two methods may seem on first 

 examination to be slight, it nevertheless in- 

 volves a fundamental question of principle, 

 so important that it calls for special emphasis 

 to any discussion of cooperative research. 



One of the great problems of astronomy is 

 the determination of the structure of the side- 

 real universe. Its complete solution would 

 involve countless observations. Nevertheless, 

 Professor Kapteyn, the eminent Dutch astron- 



