84 THE WORLD'S LUMBER ROOM. 



has found its way down to the molten rock below ; and 

 whether or no this be the sole source of volcanic energy, 

 it is certain that steam is poured forth in large quantities 

 at the beginning of an eruption, and that with such violence 

 that any fragments of rock which may have accumulated 

 in the throat of the volcano are hurled into the air with 

 much force. Masses of rock, some nine feet in diameter, 

 have been hurled fifteen miles by the great volcano of 

 Cotopaxi, and even larger blocks than these have at times 

 been sent flying several miles, or shot up to a height ot 

 6,000 feet. 



Ashes that is, fragments of lava or partly-melted rock,, 

 which have been so splashed about as to fall in spongy- 

 looking drops are poured forth by volcanoes in vast quan- 

 tities, and are frequently broken up into particles so fine 

 as to be nothing more than dust, which fills the air, and 

 plunges the whole neighbourhood for miles round into 

 darkness.* 



The most remarkable eruption which has occurred in our 

 times is that of Krakatoa, which stands upon a fissure run- 

 ning across the Straits of Sunda, and until 1883 had been 

 quite quiet for two hundred years. Many earthquakes, how- 

 ever, had recently taken place, and it may be that a larger 

 quantity of water than usual was consequently admitted into 

 the depths below. The eruption began in May, 1883, when 

 the sea for ten or twenty miles was covered with drifting 

 pumice, through which a ship cut her way with as much 

 noise as if it had been thin ice ; the volcano continued more 

 or less active for the next three months, and the worst out- 



* See Belt's " Naturalist in Nicaragua," for eruption in Coseguina. 



