646 meunier: theory of volcanoes 



and disappear without any important modification of the ex- 

 terior of the planet. 



Suppose, in the second place, that the quantity of water were 

 much larger than it actually is on the earth. In that case, when 

 the cooling has been completed, the whole planet will still be 

 impregnated with water, a surplus of which will even remain on 

 the surface. Long before that time, of course, the water will 

 be frozen, and ice will be a rock like the other petrographic 

 species. 



Let us, however, take the opposite case, supposing that the 

 quantity of water is insufficient to moisten the entire rock mass 

 during the process of cooling. In that case the volume of the 

 seas and of all the other liquid water bodies of the surface will 

 diminish until it disappears, and the globe will be completely 

 dried up while still warm. But — and this is the essential point — 

 the drying up will not necessarily cause the disappearance of 

 the volcanic phenomenon. That phenomenon is not a super- 

 ficial reaction; on the contrary, its focus is situated at a great 

 depth, and that depth is consantly increasing as the absorption 

 of liquid water continues. Thus the conditions necessary for 

 an eruption may continue long after the drying of the surface is 

 completed. For example, the water that active volcanoes emit 

 nowadays no doubt represents a contribution from the ocean 

 going back to very ancient geologic periods. The orogenic super- 

 position of moist subterranean regions by hot rocks driven tan- 

 gentially over the roof of the great geoclases may continue for 

 long geologic periods, which means that water of impregnation 

 will continue to be occluded in the substance of ancient sedi- 

 ments, which will take advantage of the smallest fissure com- 

 municating with the upper, less dense regions to inject them- 

 selves into them. by expansion. The feebleness of the atmos- 

 pheric pressure, dwindling little by little to zero, will increase 

 the number and energy, perhaps also the volume, of the out- 

 bursts, and will especially affect the relief of the material ejected 

 upon the surface as cones of lapilli and ashes, needles, chaotic 

 accumulations of scoriae, and lava flows. In addition the su- 

 perficial water, except the volcanic rains, having little by little 



