Page:Popular Science Monthly Volume 61.djvu/284

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278
POPULAR SCIENCE MONTHLY.

falling on St. Pierre, miles from the nearest crater, was still 'white hot.' All accounts agree as to the immensity and blackness of the clouds cast out from Mont Pelee with each explosion; and all agree in indicating that an important constituent of these clouds was gas, at least in part heavier than air, and at least in part inflammable. These eruptions are especially notable for the extravasation of material in gaseous form; but the gases have not yet been measured or even identified with any approach to precision. Thus far no quantitative estimates have been made of the aggregate amount of matter erupted from either Antillean volcano; but it seems probable that the total from both will not exceed one or two cubic miles, i. e., probably less than a third of that thrown out by Krakatoa alone in the memorable outbreak of 1883. No decisive indications of subsidence of the coasts or of deformation of either insular masses or sea-bottom, such as might be expected to accompany the transfer of so vast a mass of material, have yet been detected—indeed, the geographic effects of the eruptions seem to be inconsiderable. Nor were there notable tidal waves anywhere in the Antillean region, save the outflows and subsequent inrushes in the St. Pierre harbor, ascribed by Hill to the atmospheric disturbance; and even these air-waves were of but limited extent, as indicated by the absence of records at meteorologic stations more remote than that on St. Kitt's, some 200 miles north of Martinique.

The most impressive part of Pelee's lesson is the tale of terrible mortality due to the ill-chosen site of St. Pierre. The convex slopes of the great dome stretching northward and eastward from the crater are still clad in verdure; Morne Rouge, the high-lying suburb on the principal salient stretching out from the crater, suffered nothing more serious than startling tremors and disagreeable dust-showers; it was only in the topographic funnel leading from the crater to the indented roadstead that the destruction was complete. Looking back over her history, it is easy to see that St. Pierre was founded with no more foresight than that of the spider spinning her web across a frequented path; the sacrifice of the city was but the necessary price of shortsight; yet if future dwellers on the Antilles, and the folk of other volcanoridden regions, but profit by the experience of St. Pierre, the sacrifice may not be wholly vain.

So far as indicated by external manifestations, the internal mechanism of the Antillean volcanoes was in no way unprecedented or even peculiar, save, perhaps, in the high ratio of gaseous ejectamenta and the vast extent of magnetic disturbance and even these features may not be new, but only the outcome of more refined observations than those of earlier generations.

The internal mechanism of Mont Pelee and La Souffriere is fairly