194 



SCIENCE. 



[N. S. Vol. XV. No. a70. 



lege, Topeka; Treasurer, E. C. Franklin, of 

 the State University. 



The next annual meeting will be held in 

 Topeka. 



D. E. Lantz, 

 Secretary. 



THE ACADEMY OP SCIENCE OF ST. LOUIS. 



At the meeting of the Academy of Science 

 of St. Louis on the evening of January 6, 1902, 

 about forty persons present, the following of- 

 ficers for 1902 were installed : President, Henry 

 "W. Eliot; Vice-Presidents, D. S. H. Smith, 

 William E. Guy; Eecording Secretary, Wil- 

 liam Trelease; Corresponding Secretary, Er- 

 nest P. Olshausen; Treasurer, Enno Sander; 

 Librarian, G. Hambach; Curators, G. Ham- 

 bach, Julius Hurter, Hermann von Schrenk; 

 Directors, Amand Eavold, Adolf Alt. 



On behalf of herself and a considerable 

 number of other persons, Mrs. William Bouton 

 presented to the Academy a collection of 633 

 butterflies mounted on Denton tablets, on con- 

 dition that the collection should be made ac- 

 cessible to the public. 



The following papers were presented by 

 title : 



'New Species of Plants from Missouri': K. 

 K. Mackenzie and B. F. Bush. 



'Eevision of the North American Species of 

 Triodia': B. F. BusH. 



Professor A. S. Chessin exhibited a gyro- 

 scope and explained how an accurately con- 

 structed and rapidly rotated gyroscope might 

 be made to indicate the position of the meridi- 

 an plane, the direction of the polar axis of the 

 earth and the latitude of the place of observa- 

 tion, thus serving the purpose of the mariner's 

 compass, but more accurately, because of the 

 fact that the compass indicates the magnetic 

 pole and not the true pole. The following for- 

 mulae pertaining to the subject were fur- 

 nished : 



CwH cos ^ 



Cufi 



where T and T' are the durations of a com- 

 plete oscillation of the gyroscope when its axis 

 is made to remain in the horizontal and the 

 meridian planes, respectively; <« and fl the 

 angular velocities of rotation of the earth and 



the gyroscope, respectively; Aj A^, A^ and 0, 

 Ci, C\ the equatorial and the axial moments 

 of inertia of the gyroscope and the two rings 

 on which it is mounted. From these formu- 

 Ise the latitude ( A ) of the place of obser- 

 vation is derived, namely: 



cos ^- = ^ • 



Professor F. E. Nipher made a further state- 

 ment concerning his results in the attempt to 

 produce ether waves by the explosion of dyna- 

 mite. He had obtained some results which 

 seemed to show that magnetic effects could be 

 thus produced. " There is apparently no doubt 

 that great solar outbursts like the one which 

 Professor C. A. Young saw at Sherman in 

 1872* produce enormous distortions of the 

 ether. Why should it not be possible to re- 

 produce this result? It goes without saying 

 that large sun-spots may be slowly formed, 

 without such ether disturbance; and certainly 

 we can hardly expect to reproduce solar veloci- 

 ties. But terrestrial explosions do yield trem- 

 ors and sound vibrations, and these lead to ex- 

 perimental difficulties. The nickel-silver co- 

 herer can be operated by the sound-waves from 

 a tuning-fork. The coherer can be either open- 

 ed or closed, by sound-waves, when the co- 

 herer is properly placed in a magnetic field. 

 The same result may be produced by changes 

 in the magnetic field, due to the slow approach 

 of a horseshoe magnet. After the coherer cir- 

 cuit has been closed by a spark, the slow ap- 

 proach of a horseshoe magnet will often open 

 the circuit, precisely as it does when the co- 

 herer has been closed by the magnet held in a 

 position of reversed polarity. When the mag- 

 net fails to open the coherer circuit, the cause 

 is either a too rapid approach, which causes the 

 coherer to close by reversal of magnetic polar- 

 ity, or a wrong presentation of the mag- 

 net, which confirms the condition produced by 

 the spark discharge. The conditions under 

 which experiments are made as yet, with the 

 jarring due to the street traffic and the ex- 

 plosions, and the changing magnetic field due 

 to the electric cars, have proven to be a source 

 of some perplexity. It throws some doubt 

 *'The Sim,' p. 156. 



