168 



SCIENCE 



[N. S. Vol. XXVII. No. 683 



15. Photographs taken at intermediate 

 points between center and limb indicate 

 that the shifts fall off rapidly, and become 

 very small at a short distance from the 

 limb. 



26. In order to obtain radial velocities 

 from star lines that are not present in the 

 comparison spectrum it is customary to use 

 an interpolation formula to express the 

 exact relation between wave-lengths and 

 micrometer readings. These formulae do 

 not change much from plate to plate if the 

 latter are all taken with the same spectro- 

 graph, and whatever differences there may 

 be can be largely allowed for by adding to 

 the micrometer readings (B) a linear ex- 

 pression : a-\-l)- B. Assuming that this is 

 rigorously the case for short distances on 

 the plate, it is shown that the error of this 

 assumption can amount to a few hun- 

 dredths of a kilometer per second in the 

 case of plates taken with the Mellon Spec- 

 trograph of the Allegheny Observatory. 

 Consequently it is only necessary to inter- 

 polate the place of a star line linearly be- 

 tween two comparison lines in order to ob- 

 tain its displacement. This method has 

 been tried on many plates at the Allegheny 

 Observatory and has been found very con- 

 venient. The complete reduction of a 

 plate in this way occupies about ten 

 minutes. 



27. The problem of Professor Moulton's 

 paper is to find the possible role that the 

 near approaches of the stars to one another 

 may have played in sidereal evolution. 

 The answer to this problem depends upon 

 the extent of the sidereal universe, the 

 number of stars in it, and the character of 

 their motion. The discussion leads to the 

 conclusion that the relatively near ap- 

 proaches of the stars have probably been 

 an important factor in stellar evolution. 

 The paper will be published by the Car- 

 negie Institution. 



The general committee elected Professor 

 C. J. Keyser, Columbia University, vice- 

 president and chairman of the Section, and 

 Professor G. A. Miller, University of Illi- 

 nois, secretary. The Section elected Pro- 

 fessor G. B. Halsted, councilor; Professor 

 F. R. Moulton, member of the general 

 committee; Professors E. W. Brown and 

 F. R. Moulton, members of the sectional 

 committee — the former for five years and 

 the latter for four years. 



G. A. Miller, 



Secretary 



Uniteesitt of Illinois 



THE AMERICAN MATHEMATICAL SOCIETY 

 The fourteenth annual meeting of the 

 American Mathematical Society was held 

 at Columbia University on Friday and 

 Saturday, December 27-28, 1907, extend- 

 ing through two sessions on Friday and a 

 session on Saturday morning. The at- 

 tendance included fifty-three members. 

 President H. S. White occupied the chair, 

 being relieved by Vice-president P. F. 

 Smith at the afternoon session. The fol- 

 lowing were elected to membership in the 

 society: Mr. Charles Ammerman, Me- 

 Kinley High School, St. Louis, Mo.; Dr. 

 C. S. Atchison, Williams College; Mr. B. 

 H. Camp, Wesleyan University; Professor 

 W. M. Carruth, Hamilton College; Mr. G. 

 R. Clements, Williams College; Professor 

 Julia T. Colpitts, Iowa State College; Pro- 

 fessor J. N. Ivey, Tulane University; Pro- 

 fessor W. H. Jackson, Haverford College; 

 Mr. W. C. Krathwohl, Columbia Univer- 

 sity; Professor Murray Macneill, Dal- 

 housie University; Mr. C. N. Moore, 

 Harvard University; Professor Maria M. 

 Roberts, Iowa State College; Mr. E. W. 

 Sheldon, Yale University. Seven applica- 

 tions for membership were received. 



In response to the invitation of Professor 

 E. J. Townsend, it was decided to hold the 



