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POPULAR SCIENCE MONTHLY. 



over the mountain slojjes light down to the sea. It was dull red and in it 

 were brighter streaks thought to be large stones, as they seemed to give off 

 tails of yellow sparks. They bowled along apparently rebounding when they 

 struck the surface of the ground. The dark-red avalanche had a billowy sur- 

 face, and its velocity was tremendous. " The mist and steam on the moun- 

 tain top did not allow us to see very clearly how the fiery avalanche arose, 

 but we had' a perfect view of its course over the lower flanks of the hills, and 

 its glowing, undulating surface was clearly seen." The red glow faded in a 

 minute or two, and a round black boiling cloud rushed over the sea in front of 

 it, filled with lightnings. This cloud was globular as seen end on, very per- 

 fectly rounded, covered with innumerable minor rounded excrescences which 

 were filled with terrific energy. It was full of short lightnings — ' A mere 

 succession of flashing points in the great black wall of cloud.' " Many of 

 the flashes were horizontal, others shot obliquely from one lobe to another, 

 while along the base where tlic black cloud rested on the steel-gray sea, there 

 was a line of sparkling liglit. constantly changing, varying in amount, but 

 never disappearing." 



Fig 2 (a). Puff from Crater, Mt. Pelee. First Stage. 

 (Photos for T. A. Jaggar, by E. C. Rest.) 



A gentle puff of wind came from the southeast. The cloud lost its 

 violence and became a gigantic wall with a velvety appearance in the 

 moonlight, resembling a black curtain draped in folds. In size it was 

 estimated to be two miles broad and about one mile high.* The sur- 



* ' Preliminary Report,' by same authors, Proc. Roy. Soc, Vol. 70, August 

 11, 1902, p. 443. 



