204 THE STORY-BOOK OF SCIENCE 



that floats in sinister clouds and sinks down on the 

 neighboring plain, or is even carried by the winds 

 to a distance of hundreds of leagues. Finally, the 

 terrible mountain calms down, and peace is restored 

 for an indefinite time." 



"If there are towns near the volcanoes, cannot 

 those streams of fire reach them? Cannot those 

 clouds of ashes bury them?" asked Jules. 



"Unfortunately all that is possible and has hap- 

 pened. I will tell you about it to-morrow, for it is 

 time to go to bed now. ' ' 



