404 
spurs to modify the course of its operations than in the Wallibu 
Valley. 
The track to the summit passes across the Rabaca Dry Valley 
near the shore, then turns upwards through the sugar-cane 
fields of Rabaca and Lot 14. These were covered with 3 or 4 
feet of sand and scoriz, the trees all bare, their leaves stripped 
by the falling cinders; but few branches were broken, and no 
trees had been uprooted or cast down. The woodwork of the 
houses was unburnt, though the roofs of some of the verandahs, 
and of the labourers’ huts, had collapsed from the weight of 
ashes that had fallen on them. Many people were killed on 
these estates. The survivors described to us how the dark 
cloud had rolled down from the mountain, and how hot and 
suffocating the air had been when it enveloped them. But it 
was evident that the-velocity of the blast was not above that of 
an ordinary gale, and the dust it carried, though hot, was not 
incandescent. 
At Lot 14 it was seen that many trees had their limbs twisted 
off and broken, and some of the negroes’ houses had taken fire 
(probably mostly from hot falling bombs). The blast was 
more violent here, but not hot enough to set fire to the wood- 
work or char the green wood of the standing timber. 
On the flat ground above the plantation buildings (at an 
elevation of about 1000 feet), a further stage of devastation was 
encountered. The fields were here swept bare, the trees broken 
down, though not as a rule uprooted, their smaller branches 
swept away; a deep layer of black sand covered the crops of 
sugar-cane, The blast was here a violent gale. 
A little further up the effects of the blast were remarkable. 
Enormous trees had been uprooted and cast down. Their 
leaves and finer branches, of course, had disappeared. In 
every case the fallen trunks pointed directly away from the 
crater. Even the great cotton-trees, 10 feet or more in diameter, 
were broken off or uprooted. The smaller trees had in a few 
cases been swept away like straws. The larger were merely 
cast down, and lay side by side, their tops directed down the 
valley, their roots towards the summit of the mountain. Most 
were charred, some deeply, but, as the wood was green, only the 
smaller branches had been consumed. Theeffect was like that pro- 
duced by a violent hurricane, only more complete, for many of 
these trees had withstood the hurricane which ruined St. Vin- 
cent in 1898. At the lower limit of this region some curious 
effects of the hot sand blast could beseen. Where any branches 
or trunks were still standing, they invariably showed themselves 
to be burnt’ and eroded on one side—that next the crater—the 
wood having been charred and the charred material removed by 
the action of a hot sand blast. On the side away from the 
crater, the original bark was still left, unburnt, but dry and 
peeling off; that is, there had been no erosion on the sheltered 
or lee side of the stems. The wood was too green to take fire, 
but the sand had been sufficiently hot to char the surfaces which 
were exposed to it. 
Further up the hill—that is to say, above the 1500-feet level, 
there was little left of the rich tropical vegetation which had 
covered it from summit to base. Blackened remains of tree- 
trunks were to be seen, overturned or broken off near the 
ground, and buried in dark sand. The highest parts of the 
mountain are as bare and desolate a scene as could be imagined. 
The ash is 5 to 12 feet deep, and though full of large blocks and 
spongy bombs, is mostly so fine that when thoroughly wet it be- 
comes a fine mud, very tenacious and slippery, in which one sinks 
to the knee. In it there is a good deal of burnt timber, utterly 
blackened and converted into charcoal. Everything has been 
mown down, and at the same time the intense heat has consumed 
all the smaller fragments and charred the larger. There is 
nothing to show what was the velocity of the blast when it left 
the crater. After a couple of miles it was that of a hurricane or 
tornado. The limit between the zone of uprooted trees and 
that of trees still standing, but broken and much damaged, is 
surprisingly sharp. At 4 miles from the crater the blast was 
travelling at 20 to 4o miles an hour, and rapidly slowing down. 
This agrees with the evidence of an eye-witness who saw it 
when it reached the sea near Chateaubelair. It came over the 
water with a wave before it, but it did not overturn the small, 
boats which lay in its course. 
Another peculiar feature of this blast is the manner in which 
its course was modified by irregularities in the configuration of 
the ground over which it passed. To the north of the crater 
stands the encircling crater wall, already referred to as the 
Somma. There can be no doubt that a black cloud descended 
NO. 1712, VOL. 66] 
NATUKELE 
| AUGUST 21, 1902 
over this side of the mountain, though here the devastation is 
comparatively slight, and it is inferred that the high intervening 
ridge overlooking the crater served as a rampart and helped 
to protect the country behind it from the effects of the blast. 
The southern lip of the crater, on the other hand, is the lower, 
and the avalanche of hot sand seems to have poured over 
this lip almost like a fluid. Down the deep open valley between 
the {Soufriére and the Morne Garu Mountain it rushed, ever 
following the steepest descent. It clung to the valley bottoms 
and coursed along them in a manner which somewhat recalls a 
raging torrent in a river. The streams in these valleys after 
descending the first part of the hill turn sharply at a right angle 
towards the coast, deflected by the opposing mass of the Morne 
Garu. The hot blast mostly followed these valleys, and in 
them it piled up enormous deposits of sand, but part of it swept 
up the shoulders of Morne Garu, and tore up the heavy timber 
which was growing there. The direction in which the fallen 
trunks point shows that.the blast was split into two parts—one 
taking the east and one the west side of the mountain, rushing 
upwards obliquely from below. The mountain protected the 
country behind, and the line of demarcation between the burnt 
and the green forest almost corresponds with the dividing ridge. 
The south side is green; the north side towards the Soufriere 
is devastated and burnt. 
Geological Modifications. 
Apart from the changes which have taken place within the 
ciater, and the deposits of ash which have formed in the river 
valleys, and on the surface of the hill, the only other important 
geological modification of the country has been the disappearance 
of a narrow strip of coast along the leeward side of the island. 
Near the mouth of the Wallibu and from thence northward to 
Morne Ronde, the sea has encroached on the land for perhaps 
200 yards. Below Wallibu plantation there stood a village of 
labourers’ huts on a low flat beach with a bluff behind. Here 
the sea now washes the foot of a cliff some 30 feet high. This 
cliff consists of soft tuffs covered with several feet of new hot 
ashes, and is in an unstable condition, as masses are constantly 
falling down from its face. In this way a new beach is now 
forming in front of it. It is agreed by those who knew the district 
before the eruption that not only has the old beach disappeared, 
which carried the village and the public road, but that part of 
the bluff behind has also subsided. We were informed by Mr. 
T. M. McDonald, who is intimately acquainted with this coast- 
line, that similar subsidences had also taken place, though on a 
much smaller scale, at several places further north. There is no 
evidence elsewhere of any changes of level of land and sea. 
The tide-marks on the rocks and the landing-stages at the 
villages enabled us to ascertain that the level of high-water was 
at any rate within a few inches of what it had been before. It 
was clear that the alterations in the coast-line were due to local 
subsidence of the foreshores, and that they had mostly affected 
loose and ill consolidated deposits, suchas beach gravels and the 
fans of alluvium which had formed at the mouths of the streams. 
The submarine slopes on the leeward side of St. Vincent are 
very steep, averaging about I in 4. Within half a mile of 
the shore the depth is often more than 100 fathoms. 
It seems most probable that owing to the concussions and 
earthquakes produced by the explosions, some of the less 
coherent accumulations on these steep slopes slipped bodily 
into the deep. On this supposition most cf the facts would be 
explained, but at the same time it is possible that at Wallibu 
the inner margin of the depressed tract may be a fault line. It 
has a very straight trend, and it is a curious fact that this shore 
was formerly known as Hot Waters. This might indicate the 
existence of a fissure up which hot springs were rising. 
Comparison of the Soufriére with Mont Pelée. 
When we arrived at Martinique, we had the pleasure of 
meeting Prof. Lacroix, the head of the French Scientific Com- 
mission, which had spent some time in making a preliminary 
survey of Mont Pelée, and the noith-end of the island, and 
from him we obtained much valuable information regarding the 
sequence of events and the geological consequences of the erup- 
tions in that quarter. It was our intention to make merely such 
reconnaissances as would enable us in a general way to ascertain 
the points of difference and of similarity between the outburst 
of Mont Pelée and that of the Soufriére, and to see what light 
the phenomena in Martinique threw on the events which had 
happened in St. Vincent. 
