May 30, 19(12.] 



SCIENCE. 



873 



MAGNETIC DISTURBANCE AT TIME OF ERUPTION OF 

 MONT PELEE.* 



Coincident, as far as can be at present ascer- 

 tained, with the time of eruption of Mont 

 Pelee on May 8, a magnetic disturbance set in 

 which was registered on the self-recording in- 

 struments of the two U. S. Coast and Geodetic 

 Survey magnetic observatories, the one at 

 Cheltenham, Md., seventeen miles southeast of 

 Washington, and the other at Baldwin, Kan- 

 sas, seventeen miles south of Lawrence. The 

 preliminary reports received from Mr. L. G. 

 Schultz, in charge of Cheltenham observatory 

 and Mr. W. C. Bauer, in charge of Baldwin 

 Observatory are sufficient to indicate that the 

 disturbance began at practically the same in- 

 stant of time at both observatories, viz., at 

 Vh. 54m. St. Pierre local mean time. Accord- 

 ing to the newspaper reports the catastrophe 

 befell St. Pierre about 8 a.m. of May 8 and it 

 has been stated that the toAvn clock was found 

 stopped at 7h. 50m. 



Purely mechanical vibrations caused by 

 earthquakes are often recorded by the deli- 

 cately suspended magnetic needles, as for in- 

 stance the Guatemalan one which was felt at 

 the Cheltenham Observatory on April 18 from 

 about 9h. 20m. to 9h. 50m. p.m., T5th meridian 

 mean time. 



time stated and continuing until midnight of 

 the 9th. Even on the 10th tremors were still 

 discernible. (At the time of writing the sub- 

 sequent curves had not yet been received.) 



Until further information has been received 

 from other observatories, it cannot be deter- 

 mined definitely whether this magnetic dis- 

 turbance was due to some cosmic cause or came 

 from within the earth's crust and was asso- 

 ciated with the Martinique eruption. The 

 coincidence in time is however a remarkable 

 fact. 



L. A. Bauer. 



U. S. Coast and Geodetic Subvet, 

 May 17, 1902. 



THE GUATEMALA EARTHQUAKE WAVES OBSERVED 

 IN CANADA BY R. F. STUPAET. 



To the Editor of Science : By permission of 

 Professor R. F. Stupart, Director of the Me- 

 teorological Service of Canada, I send you 

 herewith seismograms (Milne system) of 

 April 18, local reckoning, recorded at Victo- 

 ria, B. C, and Toronto, Canada; also a print 

 of the magnetogram (bifilar trace) at Agin- 

 court, nine miles from Toronto. 



Each of these records the earth billows 

 emanating from the region of the recent earth- 

 quake in Guatemala. Professor Stupart states 



Fig. 1. Record of Milne Seismograph, Toronto, April 18, 1902. 



The disturbance on May 8, however, was dis- 

 tinctively a magnetic and not a seismic one 

 and hence was not recorded on seismographs. 

 The Cheltenham magnetograms exhibit mag- 

 netic disturbances amounting at times to 

 .00050 to 0.00060 c. g. s. units (about 1/350 

 of the value of the horizontal intensity) and 

 from 10' to 15' in declination, beginning at the 



* Communicated by permission of Superintend- 

 ent O. H-vTittmann, Coast and Geodetic Survey. 



that "the preliminary tremors began at To- 

 ronto 2 h. 30.5 m. a.m., April 19 of Greenwich 

 mean time, and at Victoria 2 h. 31.3 m., G. m. t. 

 Large waves began at Toronto 2 h. 35.5 m., 

 but at Victoria 2 h. 37.2 m. The maximum 

 wave occurred at Toronto 2 h. 38.0 m., but at 

 Victoria 2 h. 50.7 m. The end occurred at 

 Toronto 5 h. 24.0 m., but at Victoria about 5 

 h. 3C.4 m. The amplitude at Toronto was over 

 25 mm. 



