228 POPULAR SCIENCE MONTHLY. 



The final comments of Doctors Anderson and Flett may be quoted 

 in full : 



The avalanche of hot sand was discharged about 8:20 p.m. In a couple 

 of minutes it had reached the sea and was over. The second black cloud, 

 which was all that remained of it when the heavier dust had subsided, traveled 

 about five miles in six minutes, and very rapidly slowed down, coming to rest 

 and rising from the sea in less than a quarter of an hour. The tongue- 

 shaped steam and dust cloud was over our boat by 8:40. A few minutes after 

 that the ash was falling on our decks. 



The second black cloud did not differ in appearance fiom the first except 

 that it was larger, had a far greater velocity and swept out at least twice as 

 far across the sea. It was black from the first moment when we saw its boiling 

 surface in the moonlight. Both traveled very rapidly over the lower part 

 of the mountain, but slowed down after reaching the sea, and came to rest 

 comparatively suddenly. The lightnings on the two clouds were similar in 

 all respects. 



No blast struck us — in fact, we were becalmed — and it seemed that when 

 the black cloud ceased the blast was all over. Nor did the sea rage around us 

 as some have described who were overtaken by the dust storm. When the 

 cloud was passing overhead there was a slight rolling sea, but as the breeze 

 freshened the boat steadied, and there was no unusual disturbance. We 

 watched carefully for a strong indraught, such as was described by more than 

 one observer, but the wind that rose from the southeast was very gentle, and 

 increased gradually to a full-sail breeze. . . . 



In the cloud there was a dull, low rumble, but we heard no detonations, 

 and saw no sheet of flame, so that we both agreed that there had been no 

 sudden ignition of quantities of explosive gases. The lights in the cloud, in 

 our opinion, were lightning and nothing else. When the slopes of the moun- 

 tain were seen two days later it was evident that ' the avalanche had come 

 down approximately along the line of the Riviere Seche.' 



Comparing the records of these observers with the observations made 

 at Fort de France, we find the following simultaneous phenomena: 



Anderson & Flett. Jagyar. 



7:40 P.M. First black cloud. 7:40 P.M. Not watching. 



8:00 P.Ai. Glare and glowing stones. 8:00 p.m. Not watching. 



8:20 P.M. Red-hot avalanche. 8:20 p.m. High balloon-shaped column 



of dust. 



8:35 P.M. Avalanche cloud had come to 8:35 p.m. Column spreading to zenith, 



rest and risen from the lightnings and rumblings. 



sea. 



8:45 P.M. Avalanche cloud reaches 8:50 p.m. Wave observed and cloud 



zenith and pebbles fall. spread out to horizon. 



The dust-balloon seen from Fort de France was at least five miles 

 high when first observed, its summit subtending an angle not less than 

 30°. It rose to heights so great that, after spreading out to the horizon, 

 the dust vault was entirely above towering 'thunderhead' cumuli which 

 developed over the mountains of the island. Its first appearance at 

 Fort de France was coincident with the fiery avalanche seen off Carbet; 



