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The National Geographic Magazine 



the wise caution of looking where you 

 walk. Loose boulders would be sent 

 from time to time flying down the 

 slope, giving out that peculiar sound, as 

 of breaking glass and china-ware, which 

 had already been noted by those who 

 had made the early ascents to the 

 crater rim, and as far back as the close 

 of May, 1902. This "vitreous" or clink- 

 ery sound had been attributed by 

 some — among whom I must class my- 

 self — to a possible vesicular or obsid- 

 ian-like structure in the falling rock 

 masses ; but manifestly the condition 

 was independent of this structure, for 

 we found the rock to be everywhere of 

 compact form, destitute of gaseous 

 cavities, and nowhere even approxi- 

 mating obsidian in aspect or composi- 

 tion. Petrographically it is a light- 

 gray, fine-grained hypersthene-ande- 

 site, of almost holocrystalline texture 

 and differing but little from some of 

 the older rocks of the volcano. It seem- 

 ingly belongs to type iv of Lacroix's 

 classification of the ejected products of 

 Pelee (quartzitic andesites), although 

 some give a faint indication of loose 

 aggregation (approximating the rocks 

 of type in ?), perhaps resulting from 

 weathering, or, what seems to me more 

 likely, the action upon the surface of 

 superheated steam or other gases. As 

 before remarked, we found no scori- 

 aceous, clinkery, or vesicular masses 

 of any kind, although it might be going 

 too far to say that such do not exist 

 buried up in the wilderness of material. 

 At two points on the dome we came 

 upon the extruded smoothened sur- 

 faces of the "ribbing" which forms part 

 of the true structure of the dome itself, 

 and found them to have virtually the 

 same lithological characters as the 

 boulder masses beneath which they 

 were in greater part covered. 



Having gained a point on the dome 

 which, at times of clearing vapors, well 

 overlooked the wall of the Morne de la 

 Croix, and beyond which the further 

 ascent is complicated by projecting 

 pinnacles and a disagreeably steep gra- 



dient, we drew the line of our journey 

 and turned our steps downward. Some- 

 what more caution was necessary in 

 this descent than in the ascent, but 

 without mishap the bottom of the rain- 

 ure was found, and a slow, steady puli 

 brought us again to the rim of the 

 crater-wall. The wind was still blow- 

 ing a semi-gale in this quarter and 

 clouds hung heavily over the vertical 

 summit of the volcano. Now and then 

 the basal wreck of the great obelisk 

 protruded its tooth-like form through 

 the shifting vapors, giving to the moun- 

 tain an aspect of savage ruggedness. 



When before this visit I last stood 

 on the crater rim the great obelisk of 

 rock, like a veritable Tower of Babel,. 

 still rose 840 feet, a sheer precipice,- 

 above the summit of the dome which 

 to-day bears merely a serrated crest. 

 At that time, in the middle of 1903, the 

 fires of the volcano were still burning,, 

 and steam and sulphur vapors were 

 being puffed in great clouds through 

 the mass of the dome itself, and 

 through the zone of contact that united 

 the dome with the gray and silent rock 

 that rose out from it like a giant plug 

 or cork. At that time, and from that 

 time nearly to this, the geologist was 

 still in doubt as to the precise char- 

 acteristics of this singular volcanic ex- 

 crescence — unique apparently in our 

 world, but not unlikely duplicated in 

 some of the tall objects, sending nearly 

 straight shadows, which appear in some 

 of the large crateral pits of the moon — 

 but today we at least know what was 

 its constructural rock material, even if 

 a considerable doubt still attaches to the 

 precise method of its formation. 



The view that is seemingly most 

 generally held by geologists as to the 

 origin and construction of the Pelee 

 tower is that which has been advanced, 

 and so ably elaborated by Professor 

 Lacroix, the chief of the scientific com- 

 mission sent out by the Academy of 

 Sciences of Paris to investigate the 

 happenings on the island of Marti- 

 nique. This view is, in its simplest 



