On the Eruptions of the Soufrtire and Mont PeUe. 439 



very steep, averaging about 1 in 4. Often within half a mile of the 

 shore, or sometimes even less, the depth is over 100 fathoms. 



It seems most probable that owing to the concussions and earth- 

 quakes produced by the explosions, some of the less coherent accu- 

 mulations on these steep slopes slipped bodily into the deep. On 

 this supposition most of 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. 



When we arrived at Martinique, we had the pleasure of meeting 

 Professor Lacroix, the head of the French Scientific Commission, 

 which had spent some time in making a preliminary survey of Mont 

 Pelee and the north end of the island, and from him we obtained 

 much valuable information regarding the sequence of events and the 

 geological consequences of the eruptions 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 Pelee and that of the Soufriere, and to 

 see what light the phenomena in Martinique threw on the events which; 

 had happened in St. Vincent. 



Both volcanoes are of the same type, simple cones with a large vent 

 near the summit, and without parasitic craters. They are both deeply 

 scored with ravines, and on their south-west sides there is a broad 

 valley — occupied at Martinique by St. Pierre city, at St. Vincent by 

 the Wallibu. It is in these valleys that the destruction has been most 

 pronounced. In both, the recent eruptions have been characterised 

 by paroxysmal discharges of incandescent ashes, and a complete 

 absence of lava streams. 



In St. Vincent, however, the mass of material ejected has been 

 much greater, and a considerably larger area of country has been 

 devastated than in Martinique. That the loss of life was not so great 

 can be accounted for by the absence of a populous city at the foot of 

 the mountain. Had St. Pierre been planted at the mouth of the 

 Wallibu valley, there can be no doubt it would have been no less, 

 completely destroyed. 



On Mont Pelee, we understand that a fissure has opened on the 

 south side of the mountain between the summit and St. Pierre, from 

 which the blast was emitted which overwhelmed the city. But on the 

 Soufriere the old orifices have been made use of. The eruption of 

 Pelee began with the flow of mud lavas, but none such were seen in 

 St. Vincent. On the other hand, the hot blast which swept down on 

 the devoted city was essentially similar to that which we have 

 described as having taken place at the Soufriere. Both eruptions 



VOL. LXX. 2 H 



