National Geographic Society Expedition 209 



were disturbed again on May 20, at the 

 time of the second eruption of the 

 mountain. 



The disturbance of the magnetic nee- 

 dles was plainly due to magnetic effects, 

 and was in no sense caused by purely 

 mechanical vibrations. It .is the first 

 instance that magjictic effects caused by 

 eruptions of distant volcanoes have ever 

 been recorded at magnetic observatories. 

 Mechanical vibrations of magnetic nee- 

 dles caused by earthquakes have been 

 previously noted. For instance, the 

 Guatemalan earthquake on April 18, 

 iyo2, caused a distinct mechanical vi- 

 bration of the magnetic needles for at 

 least one-half an hour, but no magnetic 

 disturbance was registered. The dis- 

 tinct magnetic effect of the morning of 



May 8 pulled the magnetic needles 

 aside from their usual direction for 

 many hours. 



Dr. L. A. Bauer, head of the mag- 

 netic work of the Survey, has not yet 

 received information from the observa- 

 tory at Sitka whether any magnetic dis- 

 turbance was registered at this point at 

 the same time, nor has he received infor- 

 mation from foreign observatories. Un- 

 til such information is received, of course 

 we cannot state definitely that the re- 

 markable magnetic disturbances regis- 

 tered ort the mornings of May 8 and of 

 May 20 at Cheltenham and Baldwin 

 were due to the eruptions in the West 

 Indies, but the very remarkable coin- 

 cidence in time makes this conclusion 

 probable. 



THE NATIONAL GEOGRAPHIC SOCIETY 

 EXPEDITION IN THE WEST INDIES 



ON their arrival at Martinique 

 the National Geographic So- 

 ciety party separated. Prof. 

 Robert T. Hill remained in Martinique 

 to examine Mont Pelee, while Prof. 

 Israel C. Russell and Mr. C. E. Borch- 

 grevink proceeded to St. Vincent to in- 

 vestigate conditions on that island. The 

 expedition, having been authorized to en- 

 large their party, associated with them 

 Dr. Thomas A. Jaggar, of Harvard Uni- 

 .versity ; Mr. George C. Curtis, of Cam- 

 bridge, and Dr. Angelo Heilprin, of 

 the Board of Managers of the National 

 Geographic Society (President of the 

 Philadelphia Geographical Society), 

 who arrived at Martinique several days 

 after the other scientists. 



WORK OF PROFESSOR HILL 



Mr. Hill embarked on a steamer and 

 examined the coast as far north as Ma- 

 couba Point, the north end of the island, 



making frequent landings. After land- 

 ing at he. Precheur, a little village five 

 miles north of St. Pierre, he walked 

 through an area of active volcanism to 

 the devastated city. Mr. Hill, accord- 

 ing to the Associated Press dispatches 

 from Fort de France, was the first man 

 to set foot in the area of craters, fissures, 

 and fumaroles. During this trip along 

 the coast, in addition to his work of 

 investigation, Mr. Hill rescued in his 

 steamer many poor persons of Le Pre- 

 cheur, who had been tempted back to 

 their homes by the temporary lull of 

 Mont Pelee and had since found them- 

 selves in great danger. 



On his return to Fort de France he 

 issued a brief statement as to his ob- 

 servations which may be published in 

 advance of his detailed report to the 

 National Geographic Society, which 

 will be printed in this Magazine. 



" The zone of the catastrophe in Mar- 



