664 



SCIENCE. 



[N. S. Vol. XVIII. No. 464. 



fessor Franklin's paper led to a discussion of 

 considerable interest. 



Dr. Bergen Davis exhibited, in operation, 

 his apparatus in which mechanical rotation 

 is produced by the electrodeless discharge. It 

 will be remembered that the apparatus con- 

 sists of a little anemometer mounted at the 

 center of a vacuum tube. The discharge in 

 the tube is produced by an oscillating current 

 in a surrounding coil. The motion of the 

 ions constituting this current then produces 

 rotation in the anemometer. 



In a second paper by Dr. Davis the theory 

 of ' The Electrodeless Discharge ' was con- 

 sidered, the discussion being based upon ex- 

 periments made upon carbonic acid and he- 

 lium. It was found that the results in these 

 experiments could be explained upon the as- 

 sumption that ionization was produced by the 

 impact of ions, these being always present to 

 some extent. The theory developed enabled 

 the mean free path of the ions to be com- 

 puted. It was found to be 4.4 times the mean 

 free path of the molecules. The result agrees 

 very well with the value 4.3 obtained by J. J. 

 Thomson by entirely different methods. Sim- 

 ilar computation showed that an ion must 

 move through a potential of 2.5 volts in order 

 to ionize air. By different methods J. J. 

 Thomson has found about five volts for this 

 same quantity, the agreement in this case 

 being, therefore, less satisfactory. 



Ernest Meeritt, 



Secretary. 



AMERICAN MATHEMATICAL SOCIETY. 



A REGULAR meeting of the American Mathe- 

 matical Society was held at Columbia Uni- 

 versity on Saturday, October 31. The attend- 

 ance at the two sessions numbered about fifty 

 persons, including nearly forty members of the 

 society. The president of the society, Professor 

 Thomas S. Fiske, occupied the chair. The 

 following persons were elected to membership: 

 Miss Grace 0. Alden, Westfield, Mass.; Mr. 

 L. D. Ames, University of Missouri ; Professor 

 R. C. Archibald, Ladies' College, Sackville, 

 K B.; Mr. W. H. Bates, Purdue University; 



Miss Harriet D. Buckingham, Lexington, 

 Mass.; Miss Louise D. Cummings, Vassar 

 College; Mr. Harry English, Washington, 



D. C; Professor G. A. Gibson, Glasgow, 

 Scotland; Miss Mary F. Gould, Everett, 

 Mass.; Dr. O. D. Kellogg, Princeton Univer- 

 sity; Mr. W. A. Manning, Stanford Univer- 

 sity; Dr. C. M. Mason, Massachusetts Insti- 

 tute of Technology; Professor Helen A. 

 Merrill, Wellesley College; Mr. E. A. Miller, 

 Massachusetts Institute of Technology; Mr. 



E. H. Taylor, State Normal School, Charles- 

 ton, 111. ; Professor Anna L. Van Benschoten, 

 Wells College; Mr. R. E. Wilson, North- 

 western University. Nine applications for 

 membership were received. The total mem- 

 bership of the society is now 448, a gain of 48 

 since January last. 



The office of assistant secretary of the so- 

 ciety was revived and filled by the appoint- 

 ment of Dr. William Findlay, of Columbia 

 LTniversity. A list of nominations for officers 

 and members of the council was prepared and 

 ordered placed on the official ballot for the 

 election which takes place at the annual meet- 

 ing in December. A committee was appointed 

 to make arrangements for holding the next 

 summer meeting of the society at St. Louis 

 and to cooperate with the committee of the 

 exposition in organizing the mathematical 

 section of the international congresses. 



The publication by the society of the courses 

 of lectures delivered at the Boston colloquium 

 by Professors Van Vleck, White and Woods 

 is under consideration. While the society reg- 

 ularly publishes two journals, it could render 

 still greater service to mathematics in several 

 directions if even a small publication fund 

 were at its disposal, its present income from 

 membership dues being barely sufficient to 

 meet its regular outlay in this direction. In 

 view of the great work which the society has 

 accomplished, chiefly at its own expense, it is 

 to be hoped that it may soon receive a modest 

 endowment to enable it to meet its increasing 

 opportunities in a more effective manner. 



The following papers were read at the 

 October meeting: 



