3°6 



PHYSICAL GEOLOGY 



ioo miles away total darkness prevailed for 60 hours (Fig. 298). The sound of the 

 explosions was carried along the coast for 750 miles. 



(4) Mt. Pelee. — The eruption of Mt. Pelee (1902) on the island of Martinique in the 

 West Indies was remarkable because of two unusual features. (1) A great blast of 

 highly heated air mingled with incandescent dust swept down one side of the moun- 

 tain and overwhelmed the town of St. Pierre, killing all but two of its 30,000 inhabitants, 

 one of these being a prisoner in an underground cell to which the air had access only 

 through a small opening. The cause of this mortality was due almost entirely to the 

 fine, hot dust which penetrated into all of the houses and, when breathed, resulted in 

 almost instant death. The reason for the descent of the blast on one side only of the 



Pte-de Macouba 





LEGEND : 

 a Crater 

 • Mud Crater 

 "•' Fumaroles 



~" — • Mud Runs 



Annihilation Line 



- - Singe Line 



- • — Ash Line 



Fig. 299. — Map of Mt. Pelee and environs, showing the portion of the island of 

 Martinique devastated by the volcanic eruption of 1902. The breach in the crater 

 wall is also indicated. (Hill, National Geographic Magazine.) 



mountain is readily seen when the form of the crater is studied (Fig. 299). With the 

 exception of one place (opposite St. Pierre), where the Riviere Blanche had cut a deep 

 gorge, the rim of the crater was several hundred feet high. When the explosion oc- 

 1 lined its font, instead of being expended entirely upward, was partly directed through 

 li in the side of the crater, and a great cloud of intensely hot gas, dust, and 

 bombs moved down upon St. Pierre. (2) The second unusual feature was noticed 

 ■'!" 1 the principal eruption was over. It consisted in a spine of solid rock rising from 

 o), which began to grow in October, 1902, and reached an elevation 

 •■' 1 feel ai the end of seven months. Much discussion has arisen as to the origin 

 "I this spine, but it is generally believed that it was formed by very stiff lava which 

 solidified into 1 steep-sided column as rapidly as it was forced to the surface. Other 



