724 



SCIENCE 



[N. S. Vol. XXVII. No. 697 



detail of the horizontal components of 

 earthquake motion. 



The instrument is capable, of producing 

 no less than three distinct records of each 

 component of horizontal motion, making 

 six records in all; that is to say, two com- 

 ponents of horizontal motion under high 

 magnification (100 to 200, or more, if 

 necessary) ; two other records of low mag- 

 nification (1 to 10, if desired) ; and finally, 

 during destructive or strongly-felt earth- 

 quakes, a low magnification record which 

 will be inscribed on a rapidly-moving drum 

 — thus realizing practically six separate 

 records. 



The construction of the instrument was 

 shown by lantern slides. 



Report of Seismological Committee of the 

 International Seismological Association: 

 H. F. Keid, Baltimore, Md., chairman. 

 (Read by Dr. Otto Klotz, Ottawa, Can- 

 ada.) 



In the absence of Professor H. P. Reid, 

 chairman of the seismological committee, 

 Dr. Otto Klotz, of Canada, who with Dr. 

 Reid attended the meeting of the Interna- 

 tional Seismological Association at The 

 Hague in September last, read the chair- 

 man's report, of which the following is an 

 abstract : 



Twenty-two states are now members of 

 the association, England, Austria and Can- 

 ada having joined since last year. There 

 were about fifty persons present either as 

 delegates or as invited guests, and these 

 included a majority of the leading seis- 

 mologists of the world. Signor Palazzo, of 

 Italy, was the retiring president. Professor 

 A. Schuster, of Manchester, England, was 

 elected president for the next four years. 

 Professor Forel, of Switzerland, was elected 

 vice-president for two years; and the next 

 meeting of the permanent commission was 

 fixed to take place in Switzerland two years 

 hence; Strassburg was continued as the 



central bureau of the association for the 

 next four years. 



The report of the central bureau showed 

 that it had made careful studies of seis- 

 mological instruments at Strassburg during 

 the last year, and that it had published the 

 catalog of earthquakes for the year 1904. 



In the competition for a cheap seismo- 

 graph costing 300 Marks, and giving 40 to 

 50 magnification, instruments were exhib- 

 ited by Professors Agemennone, Spindler 

 and Boyer, of Gottingen, and Smitt, of 

 Utrecht. They are to be sent to Strassburg 

 and their relative efficiency carefully tested 

 before the prize is awarded. 



Many scientific papers were presented at 

 the meeting of the association. Professor 

 Weichert gave his conclusions regarding 

 the character of the interior of the, earth 

 based on the result of seismological ob- 

 servations. They confirm his earlier idea 

 of a central core of iron or steel surrounded 

 by a stony layer, and establish 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 eighteen seconds or more re- 

 veals, he thinks, the existence of a layer 

 of liquid or plastic material at a depth of 

 about 30 kilometers from the surface. 



Prince Galitzin advocated the use of 

 strong electro-magnetic damping and elec- 

 tro-magnetic recording appliances for seis- 

 mographs. 



A Reconstruction of the Water Planes of 

 the Extinct Glacial Great Lakes in the 

 Lake Michigan Basin: J. "W. Gold- 

 THWAiT, Evanston, 111. 

 In 1905 the writer made numerous meas- 

 urements of altitude of the raised beaches 

 on the west side of Lake Michigan by the 

 aid of the Wye level. The definite cor- 

 relation of several shore-lines below the 

 "highest Algonquin" was thus made pos- 

 sible. Last summer similar data were se- 



