30 



SCIENCE 



[N. S. Vol. LIV. No. 1384 



Here we may give free rein to our imagination 

 with the moral certainty that science will supply 

 nothing tending either to prove or to disprove any 

 of its fancies. 



In this connection one is reminded of a famous 

 apoth^m, 



Faith is the substance of things hoped for, the 

 evidence of things not seen. 



George C. Comstock 



ered at the conference held last September. 

 Any such arrangement would probably begin 

 with the year 1921, and, as a preliminary, the 

 " International Catalogue " should be brought 

 up to date by the publication of volumes for 

 1915-20.— iVaiure. 



QUOTATIONS 



COOPERATIVE INDEXING OF SCIENTIFIC LIT- 

 ERATURE 



Wk have shown that the core or umbra 

 of a subject is comprised in a body of homo- 

 geneous literature which unquestionably can 

 best be dealt with by its representative profes- 

 sional society, but that outside this core there 

 exists a penumbra of relevant matter dispersed 

 through a literature of gradually increasing 

 irrelevance, with the result that the recovery 

 of the relevant matter can be effected eco- 

 nomically only by cooperative effort. The so- 

 lution, therefore, would appear to be to bring 

 into existence a central bureau which should 

 deal solely with the indexing of periodicals 

 of the non-homogeneous character — and in the 

 first stages of its work, with a restricted list 

 of periodicals assigned to it by the contribu- 

 tory bodies. These bodies would receive from 

 the central bureau entries from the periodicals 

 examined corresponding to their specified re- 

 quirements. But as the professional abstracts 

 became more fully representative of progress 

 in their respective fields the need for the pub- 

 lication of the corresponding indexes would 

 tend to disappear. The institution, therefore, 

 of a central bureau would ultimately make 

 for economy in all branches of science in 

 which the publication of abstracts is admit- 

 tedly indispensable. 



So far as science is concerned, it will prob- 

 ably be found that the simplest and most 

 effective method for obtaining the necessary 

 index slips would be to invite the Central Bu- 

 reau of the " International Catalogue of Sci- 

 entific Literature " to provide them. Indeed, 

 the possibility of cooperation between the 

 " International Catalogue " and the abstract- 

 ing journals was one of the subjects consid- 



SPECIAL ARTICLES 



THE MOTIONS OF THE PLANETS AND THE 

 RELATIVITY THEORY 



Constant reference is made to the motion 

 of Mercury about the sun and to the sup- 

 posed fact that this motion can not be ex- 

 plained by the Newtonian law of gravita- 

 tion. This current idea is far from correct: 

 the motion of Mercury can be accounted for 

 fully as well, if not far better, by the New- 

 tonian law than by the Einstein law. The 

 difficulty, which has faced mathematical as- 

 tronomers for many years, is not how to ac- 

 count for the motion of Mercury, but how to 

 account for that motion without introducing 

 complications in the motions of the other 

 planets. 



In 1895 Newcomb ^ showed clearly that the 

 motion of Mercury can be fully accounted for, 

 under the Newtonian law, by one of several 

 possible distributions of matter in the im- 

 mediate vicinity of the sun and the inner 

 planets. He, however, discarded each such 

 possible explanation of the motion of Mer- 

 cury because of the difficulties encountered 

 in explaining, at the same time, the motions 

 of the other planets. Each possible explana- 

 tion of the motion of Mercury introduced a 

 new complication somewhere else- in the 

 system. 



New identically the same difficulty is en- 

 countered by Einstein. His formulas account 

 for the motion of Mercury, but fail to account 

 for the motion of Mars, and introduce a fur- 

 ther complication in the motion of Venus. 

 The supposed explanation of the motion of 

 Mercury by the Einstein formulas has been 

 stressed, but the attendant difficulties in the 

 motions of the other planets have been glossed 



1 ' ' The elements of the four inner planeta and 

 the fundamental constants of astronomy, ' ' by 

 Simon Newcomb. 



