SOUFPJERE, AXE OX A VISIT TO MOXTAGXE PELEE, IX 1902. 
449 
velocity was checked and it conld accumulate. Nine-tenths of the mass seemed to 
have been launched into the upper jDart of the two valleys above-mentioned, and 
there it was met by the opposing face of the Morne Gam. It could not ascend the 
slopes, but was split into two currents, one following the Wallibu and Wallihu Dry 
Rivers, the other the Rabaka Dry River. Into these it poured, and on the leeward 
side it coursed along till it reached the shore, for sections of the round-backed mounds 
it formed are to he seen in the sea cliffs (see Plate 24, fig. I). In the Rabaka Dry 
River the great tide of sand came down The main valley, rapidly slowing down, and it 
had come to rest l^efore it had reached the lowest part of the channel, which begins 
about a mile above the sea. This contained none of the thick banks of hot sand which 
obstructed the stream above that point. The deluge of dust and stones had poured 
down the main valley like a flood, and, gathering there, had obstructed the mouths of 
all the lateral gorges. It clearly did not drain off the whole surface and down all the 
stream channels like a fall of rain, but in one well-defined torrent it coursed along the 
ravine of the Rabaka Dry River. The trees growing on the slopes of the mountain 
and in the wooded gorges were overwhelmed, caught up, charred, reduced to shapeless 
fragments, and swept along by the avalanche. How much erosion had been effected 
by the moving mass we could not tell. There was no very striking evidence of its 
action, and in the upper parts of the mountain it seems likely that no great changes 
had been produced. But the surface was plastered with mud where it was not 
washed and scoured by the tropical rains, and, as we had no knowledge of its configu¬ 
ration before the eruption, it was not easy to form an opinion as to the effects of the 
avalanche. Further down tlie sheets of sand covered over and obliterated all traces 
of the havoc they had wrought as tliey swept down the valleys. 
The geological evidence was not sufficient to demonstrate what form the discharge 
took, what was its path, and how great was its velocity when it left the crater; but 
by the time it reached the valleys below it was a rushing torrent of sand, stones, and 
hot gases, which coursed along the valley bottoms, adapting itself readily to all 
changes in their configuration, too heavy to surmount any great height, but sweeping 
over the surface of the minor ridges, and coming gradually to rest in the deep ravines 
behind them. In the valleys of the Wallibu and Rabaka Dry River it filled the 
whole channel, and when its energy was spent it lay in banks, with irregular rounded 
upper surfaces, like glaciers of black sand.'” In the more shallow and open valley of 
the Wallibu Dry River it had not been confined to a narrow and steep-sided channel, 
but had been free to spread out laterally, and there it took the form of a broad sheet 
of sand with round-backed ridges, like wreaths of snow, pointing down the valley and 
diverging with a slightly fan-shaped arrangement. 
* The likeness to a glacier is remarked also by Mr. E. 0. Hovey, “ St. Vincent and Martinique: a 
Preliminary Report upon the Eruptions of 1902,” ‘Bull. Amer. Museum Xat. Hist.,’ vol. 16, p. 343, 
and Plate 39, fig. 1. 
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