SOUFRIERE, AND ON A YISIT TO MONTAGNE PELEE, IN 1902. 
527 
Probably, if careful inquiries had been made at the time, many similar cases would 
have been brought to light.* 
At least one party suffered death by drowning. They were in a boat, coming from 
Campobello southwards along the east coast, and were never seen again after the 
cloud had passed. 
We inquired carefully of the doctors whether they had reason to l^elieve that 
carbonic dioxide, carbon monoxide, or poisonous hydrocarbon gases could be 
considered to have pj'oduced any of the fatal effects, and whether sulphuretted 
hydrogen was joresent in such quantities as to have contributed in any way, but 
they all were of opinion that steam, hot dust, and sulphurous acid were the only 
important lethal components of the cloud, and though other gases may have beeii 
there they were in small quantities, and left no visible consequences. 
71ie Air Waves. 
All the greater eriqDtions (jf Pelee and the Soufriere during the iiujiiths of May, 
June, and July, 1902, have probably Ijeen accompanied by both air waves and sea 
^waves. The observations and records in our hands are far from complete or 
satisfactory, and we do not intend to attempt a final discussion of the phenomena in 
this paper, but we have given the evidence relating to the eruptions of the Soufriere, 
and our statements are corroborated by those of the French Commissioners, t The 
number and form of these waves, their dimensions, velocity of dispersion and range 
can be fully investigated only when all the data are to hand, and in jDarticular when 
the various Ijarographic records obtained at meteorological stations around the 
Caribbean Sea are available. The best records are those of the recording barometers 
used in the stations of the American Weather Bureau scattered through the islands, 
and those of the French Government in Martinique, and no doubt they will be fully 
discussed in all their bearings in the reports of the French and American scientists. 
The study of these waves is of importance not only from the hydrographic and the 
meteorological point of view, they also give very valuable information to the 
volcanologist. They may help us to fix the exact time of tlie outburst of the black 
clouds. It is probable that they will also indicate the relative magnitude of the 
various eruptions, and in some measure enable us to conq)are those of the Soufriere 
with those of Montague Pelee. 
The origin of the air waves is not far to seek. They are due to the sudden and 
localised increase of pressure occasioned by the outburst of large quantities of steam 
and other gases into the air. The waves must travel outwards radially, in all 
directions, from the centre. Their amplitude depends principally on the magnitude 
* Professor Isp,ael C. Russell met with certain cases of injuries of this nature, ‘ Century 
Magazine,’ vol. Ixiv., p. 798, September, 1902. 
t “ Sur I’Eruption de la Martiniq^ue,’' ‘ Comptes Rendus,’ vol. cxxxv., p. 389. 
