520 



SCIENCE 



[N. S. Vol. XLYll. No. 1221 



thread. To the other end of the thread is 

 attached a lead ball a quarter inch in diameter. 

 The length of thread and ball together is 

 equal to the width of the fan. An L-shaped 

 brass wire, with the short arm ending in a 

 loop, is fastened to the top of the kymograph 

 by the screw nearest the fan. The fan clears 

 the vertical arm of the wire by a quarter inch. 

 As the fan revolves, the lead weight swings 

 outward and winds itself momentarily about 

 the upright wire, bringing the fan to a brief 

 halt at each revolution. The speed of the 



Pig. 1. 



drum is thus reduced from one revolution in 

 half an hour to one revolution in three hours 

 and a half. Once properly adjusted the device 

 works unfailingly. Eugene L. Porter 



Department op Physiology, 



The Universitt op Pennsylvania 



THE AMERICAN MATHEMATICAL 

 SOCIETY 



The one hundred and ninety-eightli regular 

 meeting of the society was held at Columbia Uni- 

 versity on Saturday, April 27, extending through 

 the usual moining and afternoon sessions. Thirty- 

 three members were in attendance. Professor H. 

 S. AVhite presided at the morning session and Pro- 

 fessor W. B. Mte at the afternoon session. The 

 following new members were elected: Mr. Oscar S. 

 Adams, TJ. S. Coast Survey; Professor William P. 

 Parker, Union Christian College, Pyeng Yang, 

 Corea; Dr. Eugene P. Simonds, University of Illi- 

 nois. Seven applications for membership were re- 

 ceived. Professor P. P. Smith was reelected a 



member of the Editorial Committee of the Trans- 

 actions. A committee was appointed to consider 

 the question of the publication of the recent Chi- 

 cago symposium. 



The following papers were read at this meeting: 



Arnold Emch : ' ' On plane algebraic curves with 

 a given system of foci." 



J. P. Ritt : ' ' On the iteration of polynomials. ' ' 



P. P. Decker: "On the order of the system of 

 equations arising from the vanishing of determi- 

 nants of a given matrix. ' ' 



O. E. Glenn: "Modular concomitant scales, with 

 a fundamental system of formal covariants, mod- 

 ulo 3, of the binary quadratic. ' ' 



J. E. Rowe: "The quinquesecant line invariant 

 of the rational sextic curve in space. ' ' 



P. H. Safford: "Parametric equations of the 

 path of a projectile when the air resistance varies 

 as the ath power of the velocity." 



C. L. B. Moore: "Surfaces of rotation in space 

 of four dimensions. ' ' 



C. L. E. Moore : ' ' Translation surfaces in hyper- 

 space. ' ' 



Mary P. Curtis : ' ' Note on the rectifiability of a 

 space cubic." 



P. E. Sharpe and Virgil Snyder : ' ' Certain types 

 of involutorial space transformations. ' ' 



Caroline E. Seely : ' ' On kernels of positive 

 type." 



J. W. Hopkins: "Some convergent develop- 

 ments associated with irregular boundary condi- 

 tions. ' ' 



J. R. Kline: "A necessary and suflScieut condi- 

 tion that a closed connected point set that divides 

 the plane into two domains be a simple curve. ' ' 



Edward Kasner: "Equilong symmetries and a 

 related group. ' ' 



H. B. Phillips: "Punetions of matrices." 



G. H. Hallett, Jr.: "Linear order in three-di- 

 mensional euclidean and double elliptic spaces." 



H. S. Vandiver: "On transformations of the 

 Summer criteria in connection with Permat's last 

 theorem. ' ' 



H. S. Vandiver : "A property of cyclotomic 

 integers and its relation to Permat 's last theorem. ' ' 



H. S. Vandiver: "Proof of a property of the 

 norm of a cyclotomic integer. ' ' 



The San Francisco Section met at Stanford Uni- 

 versity on April 6 and the Chicago Section at the 

 University of Chicago on April 12-13. The next 

 meeting of the society will be the summer meet- 

 ing, at Dartmouth College, early in September. 



P. N. Cole, 

 Secretary 



