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SCIENCE 



[N. S. Vol. XXVII. No. 680 



committees. For instance, a special commit- 

 tee was appointed to consider the form of the 

 next catalogue of earthquakes; another to 

 consider the question of seismological bibliog- 

 raphy ; a third will collect information regard- 

 ing mistpoefPers, and a fourth will study mi- 

 croseismic movements; the latter are con- 

 tinued movements of periods usually between 

 four and eight seconds, which sometimes last 

 for hours and even days. They have been 

 observed throughout the world and have been 

 supposed to be due to variations of the barom- 

 eter, to winds, to the beating of the waves 

 upon the shore, etc. 



There were a number of scientific papers 

 presented. Professor Wiechert gave his con- 

 clusions regarding the interior of the earth 

 as the result of seismological observations. 

 He finds that the velocity of the first prelim- 

 inary tremors of an earthquake is about Y.2 

 kilometers per second at the surface of the 

 earth and increases gradually to a depth of 

 1,500 kilometers; there it suddenly increases 

 to 12.8 kilometers per second. Below that 

 depth the variations are slow for some dis- 

 tance but finally approach the velocity of 

 10 kilometers near the center. Professor 

 Wiechert considers that this confirms his 

 earlier idea of a central core of iron or steel 

 surrounded by a stony layer, and that it fixes 

 the radius of the core at 4,500 kilometers, and 

 the thickness of the stony layer at 1,500 kilo- 

 meters. The existence of long vibrations of 

 periods of 18 seconds or more reveals, he 

 thinks, the existence of a layer of liquid or 

 plastic material at a depth of about 30 kilo- 

 meters from the surface. 



Prince Galitzin advocated the use of strong 

 electro-rnagnetie damping and electro-mag- 

 netic recording for seismographs. He showed 

 a small horizontal pendulum provided with 

 coils of wires in a strong magnetic field. One 

 set of coils served to damp the instrument and 

 the second set was connected with a dead beat 

 galvanometer whose deflections are recorded 

 photographically. The velocity and not the 

 displacement of the pendulum is recorded. 

 Although requiring considerable skill for its 

 installation, this instrument promises to be 

 very valuable. 



Professor Rosenthal gave the results of his 

 studies of seismograms. He thinks that the 

 periods of vibrations, during the principal 

 part of the movement, increase progressively 

 and therefore concludes that the seismogram 

 is drawn out for somewhat the same reason 

 that the spectrum is. It is to be noted, how- 

 ever, that other observers have failed to detect 

 the progressive change of period. 



Harry Fielding Eeid 



SCIENTIFIC NOTES AND NEWS 

 A " Life of Lord Kelvin " is in course of 

 preparation by Professor Sylvanus P. Thomp- 

 son. It will be published by The Macmillan 

 Company. 



At the Chicago meeting of the American 

 Society of Naturalists, Professor D. P. Pen- 

 hallow, of McGill University, was elected 

 president, and Professor H. E. McKnower, of 

 the Johns Hopkins University, secretary. 



The president of the American Chemical 

 Society, Professor Marston T. Bogert, of Co- 

 lumbia University, has been reelected for the 

 ensuing year. 



Professor George E. Stratton, of the 

 Johns Hopkins University, has been elected 

 president, and Professor A. H. Pierce, of 

 Smith College, has been elected secretary, of 

 the American Psychological Association. 



Professor Hugo Mijnsterberg, of Harvard 

 University, has been elected president, and 

 Professor W. P. Montague, of Columbia Uni- 

 versity, vice-president, of the American Phi- 

 losophical Association. 



The Chicago Section of the American 

 Mathematical Society, meeting in affiliation 

 with the American Association, elected Pro- 

 fessor G. A. Miller chairman, and reelected 

 Professor H. E. Slaught secretary, for the 

 ensuing year. 



Dr. Walter M. Mitchell has been ap- 

 pointed director of the Haverford College 

 Observatory. 



Dr. Theobald Smith, professor of com- 

 parative pathology at Harvard University, has 

 received the degree of doctor of laws from 

 the University of Chicago. 



