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SCIENCE 



[N. S. Vol. XXXIV. No. 872 



in the future, and I shall endeavor to give 

 reasons for this forecast; but I admit 

 frankly that our habit of judging by re- 

 sults will be hard to break. It extends even 

 to the observer himself, and leads to the 

 withholding of his observations from pub- 

 lication, so that he may himself extract the 

 results from them. In the pure interests of 

 the advance of knowledge, it would be far 

 better to publish the material, so that many 

 brains rather than one might work upon it. 

 But the observer knows that by this course 

 he risks losing almost the whole value of 

 his patient work, which would pass as un- 

 earned increment to the particular person 

 who was lucky enough to make the induc- 

 tion. Hence arise quarrels such as those 

 between Plamsteed and Newton ; the former 

 l"efusing to publish his observations until 

 he had himself had an opportunity of dis- 

 cussing them, while Newton and Halley ex- 

 erted their powerful influence in the con- 

 trary sense. This situation by no means 

 belongs to a bygone age; it may and does 

 arise to-day, and will continue to arise so 

 long as the recognition of the observer's 

 work is inadequate. It was mentioned a 

 few minutes ago that Mr. Campbell had in- 

 curred adverse criticism by accumulating a 

 considerable mass of unpublished observa- 

 tions. Let me be careful not to suggest 

 that his primary motive was the desire to 

 have the first use of them, for I happen to 

 know that there was at least one other good 

 and sufficient reason for his action in the 

 difficulty of finding funds for publication, 

 a difficulty with which observers are only 

 too familiar. But whatever the reason, 

 there were those who regretted the delay in 

 publication as hindering the advance of 

 science. The whole qiiestion is a delicate 

 one, and might have been better left un- 

 raised at the moment but for a most curious 

 sequel, which puts clearly in evidence the 

 importance of the observer and the desira- 



bility of allowing him to discuss his own 

 work. To make this clear a small digres- 

 sion is necessary. 



During the last half-dozen years astron- 

 omers have been startled on several occa- 

 sions by pieces of news of a particular 

 kind, indicating the association of large, 

 widely scattered groups of stars in a com- 

 mon movement. The discussion of these 

 movements is to occupy the special atten- 

 tion of this section at one of our meetings, 

 which is an additional reason for brevity 

 in the present allusion. Possibly also most 

 members of the section have already heard 

 of Professor Kapteyn's division of the 

 great mass of bright stars into two distinct 

 groups flying one through the other; and 

 again of the discovery by Professor Boss of 

 a special cluster of stars in the constella- 

 tion Taurus, moving in parallel lines like a 

 flock of migrating birds. The fascination 

 of this latter discovery, and of one or two 

 others like it, is that when the information 

 supplied by the spectroscope is combined 

 with that furnished by the long watching 

 of patient observers, we can determine the 

 distance of the cluster and its shape and 

 dimensions. We realize, for instance, that 

 there is a large flat cluster migrating just 

 over our heads, so that one member of it 

 (Sirius) is close to our sun — that is to say, 

 only three or four light-years from him. 

 "Close" is a relative term; and the dis- 

 tance traveled by light in three years is 

 from some standpoints by no means des- 

 picable. But it is small in comparison 

 with the dimensions of the cluster, which 

 is about one hundred light-years from end 

 to end. The study of these clusters will 

 doubtless occupy our close attention in the 

 immediate future; and it is very natural 

 than the discovery of one should lead to 

 the search for others. Accordingly, we 

 heard last autumn with the deepest inter- 

 est, but with modified surprise, the an- 



