29G DR. TEMPEST ANDERSON ON THE ERUPTIONS OF THE SOUFRIERE IN 
Montagne Pelee in Martinique. 
When we visited Martinique in 1902, it was “our intention to make merely such 
reconnaissances as would enable us in a general way to ascertain the points of differ¬ 
ence 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,and this being understood, we had the advantage of a 
friendly conference with Professor Lacroix, the Chief of the French Commission, 
who most courteously discussed his observations and conclusions with us. These 
he has since embodied in a monumental volume published by the Academy of Sciences,! 
and we have already indicated the chief points of difference and similarity between 
the two volcanoes, both in the preliminary and full report, so that it now only 
remains to compare the history of the two volcanoes since the great eruption, and to 
note the changes which, during a visit in March, 1907, I observed to have recently 
taken place in the crater and the slopes of the mountain, especially the region of the 
Riviere Blanche, and, since Professor Lacroix’s great work is not very accessible to 
English readers, to draw attention to one or two of the most remarkable phenomena 
described in it. 
The Crater and the Spine .—The great spine which has formed so peculiar and 
novel a feature in the eruption of Montagne Pelee had no counterpart in the Soufriere 
of St. Vincent, and this constitutes the most important difference between the 
outbreaks of the two volcanoes, which in other respects were so remarkably similar. 
When we visited Martinique In 1902, there was in the upper part of the mountain, 
at the head of the valley of the Riviere Blanche, a great “triangular fissure,or 
V-shaped gap, out of which, on July 9, we saw the descent of an incandescent 
avalanche, which was the counterpart of that which destroyed St. Pierre. Through 
that gap, as the trade-wind clouds momentarily dispersed, we caught occasional 
glimpses of a bank of large loose angular blocks of stone at a high temperature, which 
rolled down at intervals, accompanied by the discharges of volumes of dust-laden 
steam. We also saw several times for a few moments a large pointed rock, reaching 
to a height of perhaps 100 feet, or more, above the top of the dome of stones, but as 
we were ignorant of the exact topography of the locality, which was not accurately 
marked on the official maps, we could not ascertain for certain that it was more than 
an unusually large crag on the further lip of the crater, and accordingly did not 
particularise it in the report. This uncertainty as to the topography has now been 
cleared up. The map in Professor Lacroix’s book (p. 120) correctly represents the 
* Preliminary Report. ‘ Roy. Soc. Proe.,’ vol. LXX., 1902, p. 439 ; and Part I., p. 478. 
f ‘La Montagne Pelee et ses Eruptions,’ par A. Lacroix, Paris. Masson et Cie., 1904. 
| Part I., p. 491, called “cleft” in the Preliminary Report, pp. 440, 441, and “Echancreur en V” by 
Lacroix. 
