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Our Surroundings 



J. A. Glenn. 



FOSSIL OF A STAR FISH 



A rock form of a creature that lived ages 

 ago. 



the surrounding rock, but often it is of a different kind. In either 

 case these forms, or fossils, can be broken out of the rock without 

 destroying them and they show how the animal or plant looked. 



The study of these fossils is 

 very interesting and scientifi- 

 cally valuable, as they tell us 

 much about the early life his- 

 tory of the earth. 



Volcanoes. Not infre- 

 quently in the history of the 

 world the crust of the earth 

 has been broken open by 

 tremendous pressures from 

 within. When this happens, 

 terrific explosions result and 

 dust, cinders, and molten rock, 

 or lava, are hurled out great 

 distances. In most cases such an eruption leaves an elevation, 

 usually more or less conical in form, known as a volcano, which 

 is sometimes the scene of later violent eruptions occurring at 

 irregular intervals, often centuries apart. 



Mount Vesuvius is perhaps the most famous of volcanoes. It 

 is located in the densely populated region near Naples, Italy. 

 The date of the formation of this mountain is not known, but 

 at the time of its first recorded eruption it had lain quiet and 

 apparently dead for centuries. In the year 63 A. D., earth tre- 

 mors were felt near the mountain, and these gradually increased 

 in frequency and violence until the year 79, when a terrific erup- 

 tion wiped out three towns and thousands of lives. Other violent 

 eruptions took place in 1631 and 1906, doing immense damage 

 to life and property. 



Volcanoes differ from other mountains in shape, for their 

 sides are concave while those of other mountains are convex. Their 

 size and appearance moreover are often changed during an erup- 

 tion. The entire top of Vesuvius was blown off by the eruption 

 in 1906 and its height reduced from 4,275 feet to less than 4,000 

 feet. 



