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A rumbling sound, as of thunder, often is heard be-^ 

 fore a breaking out, and a tremenduous motion of the 

 earth near the place, plainly showing what a contest is 

 raging inside, and what pow^erfnl exertions are being 

 made by the imprisoned substance to effect an escape, 

 and when the crust can no longer resist the pressure it 

 gives way and the whole mass is thrown violently up- 

 ward. Sometimes it shoots up nearly perpendicular, in 

 which case it very often falls directly back into the 

 crater. Volcanoes are widely distributed over ail parts 

 of the earth, and are numerous, although all are not 

 active. They are more abundant along sea coasts and 

 large mountain chains. Lava is mostly of a grayish 

 brown color when cool, and is sometimes made into 

 very pretty articles. We learn by earthquakes and 

 volcanoes the condition of the interior of our earth — h 

 sea of fire and turmoil, a wonderful thing indeed to 

 realize. Think of a globe the inside of which is on fire 

 and the outside upon which we live being the hardened 

 or cool crust. The earth is supposed to have been one 

 huge heated mass at one time, and when cooling the 

 large rocks and interesting formations now found were 

 formed. One proof of this existing heat is that cer- 

 tain kinds of rocks which are formed in the presence 

 of great heat are found to underlie all others, or are 

 found deeper in the earth. 



