232 THE ERUPTION OF KRAKATOA IN 1883 



removed, and where the land had been 300 feet high a hollow 

 was formed over a thousanti feet below the sea level. The northern 

 part of the peak of Rakata was blown away, exposing a magnificent 

 section, Figure 4, that has enabled geologists to study the internal 

 structure of the volcano. The island Polish Hat disappeared entirely, 

 and Lang and Verlaten were increased in size; the former slightly, the 

 latter to about three times its former area; while a considerable addi- 

 tion was made to the height of both. The materials thrown from the 

 volcano seem to have covered the sea bottom, within a radius of 10 



Fig, 5. — Outline of the Crater of Krakatoa as it is at the present time. 



The broken line indicates the portions blown away during the eruption of August, 1883, 

 and the changes in form of the flanks of the mountains by the fall of ejected materials 

 upon them. From the " English Krakatoa." 



or 12 miles, to a depth of from 12 to 60 feet. There is some doubt on 

 this subject, however, as the waters surrounding the island had never 

 been carefully sounded, and no accurate survey had been made. There 

 is good reason to believe that the floor of the ocean was raised during 

 the eruption, causing the great sea waves that will be referred to below. 



Along a line about nine miles in length, extending westward from 

 the great crater, a depression seems to have taken place which "was 

 not improbably due to the opening of a fissure on the flanks of the 

 submerged cone." During the eruption two small islands were formed, 

 but both were soon reduced to shoals by the action of the waves. These 

 islands are supposed to have been caused by parasitic cones that had 

 arisen upon the northern flank of Rakata. 



The watery vapor thrown into the air reached a height variously 

 estimated from 12 J to 17 and possibly 23 miles. On reaching the limit 

 of its elevation, the mass spread itself and gave rise to the "pine-tree" 

 appearance so often seen during the eruptions of Vesuvius. The sur- 

 rounding country was enveloped in darkness for nearly twenty-four 

 hours. The electrical phenomena accompanying the explosion were 

 on a grand scale; the lightning darted through the dark clouds "like 

 huge serpents," and "balls of fire" rested on the masts and yardarms 

 of vessels 40 miles away. 



