January 15, 1903 J 



NA TURIi 



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were fragments of the ancient lavas and tuff agglomerates in the 

 throat of the volcano, those coming out afterwards were 

 unoxidised and seemed to consist of new material, which had 

 solidified, however, before reaching the atmosphere, though the 

 larger lapilli in the September eruptions seemed to be bits of 

 ancient lavas. 



-La Soufriere, St. Vincent, from Richmond estate 

 ment of the sea are shown along the coast. Pho 



The ejected blocks were of andesitic lavas, lor the most part 

 at least, and showed that they had been subjected to a high 

 temperature, but had not been melted. Some of such blocks 

 found four miles from the crater on the windward side were 

 thought to weigh fifty pounds. The bombs noticed were of the 

 " bread-crust " variety, similar to, but not as perfect as, those 

 observed on Mont Pelee or those described by Johnston- Lavis 

 and others from the 1888 eruption of Vulcano. Some of the 

 bombs were of somewhat pumiceous and others of dense lava 

 and they showed by their surface that they had been in a molten 

 or half-molten condition in the throat of the volcano. 



The great accumulations of hot lapilli and dust formed in the 

 radial valleys, notably those of the Rozeau, Trespeand Wallibou 

 rivers on the west and of the Rabaka dry river on the east, 

 retained their heat for a long time after the eruptions and gave 

 rise to secondary, or superficial, eruption phenomena of striking 

 character and considerable interest. The river water and the 

 water from the tropical showers percolating through the beds 

 came into contact wiih the still highly-heated interior, causing 

 violent outbursts of dust-laden steam. One such outburst from 

 the Wallibou Valley near the sea, in the afternoon of May 30 

 sent up a column of such vapour fully a mile in height with all 

 the cauliflower-like convolutions and mushroom-shaped lop 

 which are characteristic of a crater eruption-cloud. The 

 Wallibou was so overloaded with volcanic ash that it could flow 

 only in pulsations, intervals of from fifteen to forty seconds 

 being needed for the stream to gather strength to push its way 

 along with its load. The freshly fallen dry dust presented a ridged 

 surface like that of wind-drifted snow. 



The area of devastation on St. Vincent is very large in pro- 

 portion to the total area of the island. After plotting it out 

 carefully on the British Admiralty chart and measuring the area 

 with a planimeter, I find that due to the May eruptions to be 

 forty-six square miles, ptactically one-third the entire area of the 

 island. From much of this devastated area, however, the ashes 

 are being washed off so rapidly by the rain that vegetation is 

 already asserting itself, and within another year crops will be 

 growing there again. 1 



1 Newspaper reports and private advices from St. Vincent show that the 

 area of devastation has been extended on the leeward side of the island by 

 the tremendous eruption of September 3-4 about four miles south of the 

 boundary indicated on the map herewith presented, while the whole 

 western portion of the devastated area got a heavy additional coat of 

 lapilli. The windward side did not suffer materially from this eruption, but 

 the eruption of October 15-16 extended the area on the windward side. 



The deaths on St. Vincent are assigned, principally, to the 

 following causes:— (1) most important, asphyxiation by hot, 

 dust-laden steam and air ; then (2), burns due to hot stones, 

 lapilli and dust ; (3), blows by falling stones ; (4), nervous 

 shock ; (5), burning by steam alone, and (6), probably, strokes 

 of lightning. The deadly character of the dust-laden steam 

 undoubtedly was enhanced by the presence 

 of a considerable percentage of sulphur 

 gases (SOo and H.S). The action of 

 steam would account for the burns received 

 under the clothing where the clothing was 

 not charred. No autopsies were made on 

 the bodies of persons killed by either 

 volcano, so far as the author is aware. 

 The positions in which many of the bodies 

 were found indicated death by asphyxi- 

 ation. 



Mont PtUe. 



The area of devastation caused by the 

 eruptions of Mont Pelee from May 5 to 

 August 28 was less than that caused by 

 the May eruptions of La Soufriere. The 

 author, after plotting it upon the Admiralty 

 chart and measuring it with a planimeter, 

 estimates the area most seriously affected 

 at thirty-two square miles, but observes 

 that the eruptions since August 28 have 

 greatly extended the area to the north, 

 east and south-east, probably more than 

 doubling the earlier devastation. The 

 area of distribution of the ejecta cannot be 

 estimated with any degree of accuracy for 

 lack of data. There is no reason for 

 supposing that it is much, if any, less than 

 the area affected by La Soufriere. The 

 shocks or detonations from some, if not all, of the great 

 eruptions were felt in Antigua, St. Kitts, St. Vincent, Trinidad 

 and other islands, ihough not in the intervening islands of St. 

 Lucia and Dominica. 



The material ejected by Mont Pelee during the series of 

 eruptions consists of dust in vast quantities, fine and coarse 

 lapilli, bread-crust bombs of all sizes from one inch in diameter 

 upwards, and blocks of small and great size, the ctacked 



landslides and encroach 

 E. Taylor. 



F*. 2.— St. Pierre Valley of the Roxelane or Rivitre des P.lanchiseusses 

 in the northern part of the city, as it appeared May 22, 1902. Photo by 

 E. O. Hovey. 



condition of which shows that they had been highly heated. 

 The bread-crust bombs are more perfect in their development 

 than are those of La Soufriere. The largest mass which seemed 

 to be a bomb, was one fifteen feet long, lying on the south-east 

 slope of Morne Lacroix at an elevation of 3950 feet above the 

 sea. Several bombs between 2 and 3 feet in longest dimension 



NO. I733, VOL. 67] 



