Mat 21, 1920] 



SCIENCE 



509 



raphies of Benjamin Osgood Pedrce, and Cleveland 

 Abbe, and the bound volume distributed. The fol- 

 lowing biographies forming a part of Volume IX. 

 have been completed and distributed : William Bul- 

 lock Clark by John M. Clarke; Arnold Hague by 

 Joseph P. Iddings; Eugene Waldemar Hilgard by 

 Frederic Slate; James Dwight Dana, by L. V. Pirs- 

 son; James Mason Crafts, by Charles B. Cross; 

 Lewis Boss, by Benjamin Boss, and Alpheus Spring 

 Packard, by T. D. A. Coekerell. That of Charles 

 Sedgwick Minot is now in page proof. 



The Eeport of the National Academy of Sciences 

 has been issued and the fourth Annual Eeport of 

 the National Eesearch Council will be issued in 

 separate form in a few days. The Proceedings 

 have reached the third number of the sixth volume. 



Since the last meeting, two members have died. 

 Louis V. Pirsson, elected 1913, died December 8, 

 1919, and Horatio C. Wood, elected in 1879, died 

 in 1919. This leaves an active membership of 175 

 members, 1 honorary member and 31 foreign asso- 

 ciates. Gustav Eetzius, foreign associate, died on 

 July 12, 1919. C. G. Abbot, 



Home Secretary 



MATHEMATICAL MEETINGS AT THE 

 UNIVERSITY OF CHICAGO 



The twenty-seventh summer meeting and 

 ninth, colloquiuni of the American Mathe- 

 matical Society will be held at the University 

 of Chicago during the week beginning Mon- 

 day, September 6, 1920. The sessions of the 

 Mathematical Association of America will 

 occupy Monday morning and afternoon. The 

 coimcil of the society will meet on Monday 

 evening'. The regular sessions of the society 

 will occupy Tuesday morning and afternoon 

 and Wednesday morning. The joint dinner 

 of the society and the association will be held 

 on Tuesday evening. 



The University of Chicago will open two of 

 its dormitories, one for men and one for 

 women, during the week of the meeting, and 

 meals will be provided on the im.iversity 

 grotmds. Advance information on these mat- 

 ters can be obtained from Professor H. E. 

 Slaught. 



The colloquium will open Wednesday after- 

 noon and will est«nd through Saturday morn- 

 ing. It will consist of two courses of five 

 lectures each, as follows: I. Professor G. D. 



BirkhofE, of Harvard University : " Dynamical 

 systems." The last forty years have wit- 

 nessed fundamental advances in the theory of 

 dynamical systems, achieved by Hill, Poin- 

 care, Levi-Civita, Sundman, and others. The 

 lectures will expound the general principles 

 underlying these advances, and will point out 

 their application to the problem of three 

 bodies as well as their significance for general 

 scientific thought. The following topics will 

 be treated: Physical, formal, and computa- 

 tional aspects of dynamical systems. Types 

 of motions such as periodic and recurrent 

 motions, and motions asymptotic to them. 

 Interrelation of types of motion with partic- 

 ular reference to integrability and stability. 

 The problem of three bodies and its extension. 

 The significance of dynamical systems for 

 general scientific thought. 



II. Professor F. E. Moulton, of the Univer- 

 sity of Chicago : " Certain topics in functions 

 of infinitely many variables.'' I. On the 

 definition and some general properties of 

 functions of infinitely many variables. II. 

 On infinite systems of linear equations, iii. 

 Infinite systems of implicit functions. TV. 

 Infinite system of differential equations. V. 

 Applications to physical problems. 



THE SOUTHWESTERN DIVISION OF THE 



AMERICAN ASSOCIATION FOR THE 



ADVANCEMENT OF SCIENCE 



A MEETING of the council of the American 

 Association for the Advancement of Science, 

 held in Washington on April 26, approved the 

 organization of the Southwestern Division of 

 the Association, which was tenatively made in 

 a meeting of delegates held at the University 

 of Arizona, Tucson, Arizona, on Saturday, 

 April 10. 



At that meeting Dr. D. T. MacDougal was 

 delegate from the American Association. 

 Local delegates came from Prescott, Phoenix, 

 and Tucson, Arizona Albuquerque, New Mex- 

 ico and El Paso, Texas. 



Dr. Edgar L. Hewett, of the School of 

 American Eesearch, director of the Archaeo- 

 logical Institute, director of the State Mu- 

 semn at Sante Fe, K". M., and the Archaeo- 



