330 ERUPTION OF THE SOUFRIEKE IN ST. VINCENT. 



the night of the eruption. There was no hiva. We saw no explosions 

 of combustil^le gases and nothing like a sheet of flame. We were 

 agreed that the scintillations in the cloud were ordinary lightnings, 

 which shot from one part of its mass to another, and partly also struck 

 the sea beneath. 



The most peculiar feature of these eruptions is the avalanche of 

 incandescent sand and the great black cloud which accompanies it. 

 The preliminary stages of the eruption, which may occupy a few days 

 or onl}^ a few hours, consist of outbursts of steam, flne dust, and stones, 

 and the discharge of the crater lakes as torrents of water or of nuid. 

 In them there is nothing unusual, but as soon as the throat of the 

 crater is thoroughly cleared and the climax of the eruption is reached, 

 a mass of incandescent lava rises and wells over the lip of the crater 

 in the form of an avalanche of red-hot dust. It is a lava blown to 

 pieces by the expansion of the gases it contains. It rushes down the 

 slopes of the hill, carrying with it a terrific blast which mows down 

 everything in its path. The mixture of dust and gas beha\es in many 

 ways like a fluid. The exact chemical composition of these gases 

 remains unsettled. They apparently consist principally of steam and 

 sulphurous acid. There are many reasons which make it unlikel}^ 

 that the}' contain much oxygen, and they do not support respiration. 



After visiting Martinique we proceeded to Dominica, where Dr. Flett 

 visited the Soufriere at the south end of the island and the famous 

 Boiling Lake and Grand Soufriere. There have been few signs of 

 increased volcanic activity here or in St. Lucia during the recent erup- 

 tions. Dr. Tempest Anderson spent some dtiya in Grenada in an exam- 

 ination of the lagoon at St. Georges, but particulars regarding these 

 islands may be I'eserved till a fuller report appears. 



DESCRIPTION OF THK Pi.ATKS. 



Plate I. — Mv)d Pelfr from the west. — Taken from the sea near I'rechenr, a village 

 north of St. Pierre. This view shows how the mountain is cut up into deep ravines 

 by the tropical rains. Part of the summit is concealed by clouds, and the fissure 

 from which the eruption was proceeding was apparently behind and to the ri^ht 

 of the small central peak in the background. 



Plate II. — Mont Pelee from the southwest. — This photo,i,napli \\as taken from the sea 

 off the mouths of the Riviere Seche and Riviere Blanche, which are about 2 miles 

 north of St. Pierre. It shows the rugged character of the mountain, the summit 

 of whit-h is concealed by clouds. The slope in the foreground is the track of the 

 avalanches which descended from the triangular (dark-colored) fissure to the right 

 of the central peak. 



Plate HI. — 3font Pelee in erxeptUm. — Taken from a sloop off St. Pierre on the after- 

 noon of July 9. It shows the "cauliflower" shapes assumed by the clouds of dust 

 and steam as they drifted westward out to sea. The lightei'-colored cloud to the 

 east (or right) is the trade-wind cloud which so constantly cdvcrcd the summit. 

 A small light-colored cloud patch just below this, (m the right-hand (eastern) side, 

 indicates the fissure from which the eruption chiefiy i)roceeded. The eruptive 

 " avalanche" of volcanic material descended the slopes in the center and rather to 

 the left of the foreground. St. Pierre is to the right, outside the picture. 



