500 



SCIENCE. 



[N. S. Vol. XXIII. No. 587. 



who expect to attend the International Geo- 

 logical Congress in the city of Mexico next 

 September will be interested to read the paper 

 by F. N. Guild on ' El Institute Geologica de 

 Mexico.' The number concludes with an in- 

 teresting editorial on the consolidation of the 

 Geologist with Economic Geology. 



SOCIETIES AND ACADEMIES. 

 THE AMERICAN PHYSICAL SOCIETY. 



A REGULAR meeting of the Physical Society 

 was held in Fayerweather Hall, Columbia Uni- 

 versity, New York city, on Saturday, February 

 24, 1906. President Barus presided. 



On motion the president, the secretary and 

 E. B. Kosa were made a committee to prepare 

 a memorial to Congress urging the passage of 

 the pending bill providing for the use of the 

 metric system in all the government depart- 

 ments. 



On motion a committee was appointed con- 

 sisting of A. G. Webster (chairman), M. I. 

 Pupin and P. 0. Hewitt, to consider the prac- 

 ticability of securing for the Physical Society 

 an endowment fund, the income of which shall 

 be available to meet the expense of committees 

 appointed by the society to investigate and re- 

 port on special topics of importance. 



The following papers were read: 



W. G. Cady: 'A Direct-recording Jlagnetic 

 Declinometer.' 



W. G. Cady : ' A Macliine for Compounding Sine 

 Curves.' 



A. W. Smith: 'The Damping of a Ballistic 

 Galvanometer.' (Read by title.) 



E. L. Nichols and Ernest Meeritt : ' Further 

 Experiments on the Decay of Phosphorescence in 

 Sidot Blende.' 



E. L. Nichols and Ernest Merritt : ' The De- 

 cay of Phosphorescence in a Certain Specimen of 

 Willemite.' 



E. B. Rosa: 'The Gray Absolute Electro- 

 dynamometer.' 



B. B. Boltwood : ' On the Relative Proportion of 

 the Total a-ray Activity of Radioactive Minerals 

 due to the Separate Radioactive Constituents.' 



H. M. Dadourian : ' The Radioactivity of 

 Thorium.' 



Carl Barus : ' Nucleation and Ionization in 

 CO; and Coal Gas.' 



H. T. Barnes : ' Temperature Records of Noc- 

 turnal Radiation.' 



E. F. Nichols : ' On the Possible Separation of 

 Electric Charges by Centrifugal Accelerations.' 



The spring meeting of the society will be 

 held in Washington. ^^^^^^^ Meeritt, 

 Secretary. 



the SAN FRANCISCO SECTION OF THE AMERICAN 

 mathematical SOCIETY. 



The ninth regular meeting of the San 

 Francisco Section of the American Mathe- 

 matical Society was held at Stanford Uni- 

 versity, on February 24, 1906. Sixteen mem- 

 bers of the society were in attendance; in 

 addition to these there were present a number 

 of high school teachers of mathematics who 

 are not members of the society. The fol- 

 lowing papers were read and discussed during 

 the two sessions of the section : 



Dr. J. H. McDonald : ' The theory of the reduc- 

 tion of hyperelliptic integrals of the first kind 

 and of genus 2 to elliptic integrals by a trans- 

 formation of the jith order.' 



Dr. W. a. Manning : ' On nuiltiple transitive 

 groups.' 



Mr. Arthur Ranum : ' A new kind of congru- 

 ence-group and its application to the group of 

 isomorphisms of any abelian group.' 



Professor D. N. Lehmee: ' On tlie orderly list- 

 ing of substitutions.' 



Professor D. N. Lehmer: 'Note on the values 

 of s! of given modulus which give maximum or 

 minimum values to the modulus of a given ra- 

 tional integral function of z.' 



Professor R. E. Allardice : ' Note on Le- 

 gendre's equation.' 



Professor R. E. Allardice : ' On the multiple 

 points of unicursal curves.' 



Professor E. J. Wilczynski: 'Outline of a 

 projective differential geometry of curved sur- 

 faces.' 



JMr. E. T. Bell : ' Method of dealing with the 

 problems connected with prime numbers.' 



De. T. M. Putnam : ' Theorems on perfect num- 

 bers.' 



Dr. J. H. McDonald : ' A method of simul- 

 taneous approximation to two consecutive roots 

 of an algebraic equation of degree n all whose 

 roots are real.' 



Dr. J. H. McDonald : ' Remarks on the calcu- 

 lation of roots of Bessel functions.' 



