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The National Geographic Magazine 



on neighboring islands, and the sound 

 was heard 200 miles away. As the 

 island consisted chiefly of ashes, it has 

 since then been rapidly consumed by 

 the waves, and will soon disappear un- 

 less new eruptions occur. 



"In northern California there is a 

 cinder cone of remarkably perfect form 

 and certainly of recent date, although 

 there is no record of its eruption. The 

 cone, built of loose ashes, is 2,000 feet 

 in diameter at its base, and rises 640 

 feet to a circular rim enclosing a crater 

 240 feet deep. It is perfectly barren. 

 Although of moderate height, its ascent 

 is difficult, as the ashes slide under a 

 man's weight. A stream of lava emerges 

 near the base of the cone, and, flowing 

 westward into a neighboring valley, 

 forms a large field a mile wide and 

 nearly three miles long. The surface 



of the field is so covered with great 

 clinkery blocks of lava as to be almost 

 impassable. It is still unweathered and 

 barren. The edge of the field is a steep 

 clinkery slope 100 feet high. It ob- 

 structs a stream from the south, which 

 forms Snag Lake, so called from the 

 dead trees still standing in it. The lake 

 outlet runs north along the west edge 

 of the lava. On all sides the surface 

 of the country is covered with a layer 

 of volcanic ashes and dust, six or more 

 feet deep near the cone, thinner and 

 finer farther away, yet recognizable at 

 a distance of eight miles. From the 

 size of trees growing on the ashes, it is 

 estimated that the cinder cone was built 

 about 200 years ago. The lava flow is- 

 younger, but none of the Indians or 

 early settlers thereabouts (1845) ob- 

 served its eruption." 



G. H. G. 



MAGNETIC DISTURBANCE CAUSED BY 

 THE EXPLOSION OF MONT PELEE 



IN explosive violence the eruption of 

 Mont Pelee was to Krakatoa but 

 the bursting of a bubble. Krakatoa 

 was heard distinctly 3,000 miles away ; 

 the sound of Mont Pelee penetrated 

 only 200. Krakatoa sent its dust round 

 the globe ; the dust of Mont Pelee was 

 carried less than 300 miles. But in one 

 very important respect, the electrical 

 phenomena accompanying the explo- 

 sion, Mont Pelee apparently surpassed 

 Krakatoa ; for the first time in the his- 

 tory of volcanic eruptions, so powerfu 

 electro-magnetic waves were shot out by 

 a bursting volcano that magnetic needles 

 2,000 and 5,500 miles away were disturbed 

 for many hours. 



Mr. O. H. Tittmann, Superintendent 

 of the U. S. Coast and Geodetic Survey, 

 reports that the magnetic needles at the 

 Coast Survey magnetic observatories 



at Cheltenham, Maryland, at Baldwin,. 

 Kansas, and also in the Hawaiian Isl- 

 ands, were disturbed on the morning 

 of May 8 at the time of the volcanic ex- 

 plosion at Pelee. The needles are very 

 delicately suspended, and register auto- 

 matically by photographic means the 

 minutest variation in the direction and 

 intensity of the earth's magnetic force. 

 The magnetic disturbance began at the 

 Cheltenham observatory at a time cor- 

 responding to 7.53, St. Pierre local 

 mean time, and at the Baldwin obser- 

 vatory 7.55, St. Pierre time. Reports 

 from St. Pierre state that the explosion 

 of Mont Pelee occurred a few minutes 

 before S o'clock in the morning. A 

 clock in St. Pierre was stopped at 7.50- 

 a. m. The magnetic disturbance was 

 thus almost instantaneously recorded at 

 the Survey observatories. The needles- 



