CHAPTER VIII.
WHY PARLEY BELIEVES THAT THERE IS A GREAT SOURCE OF HEAT WITHIN THE GLOBE.
If you have attended to what I have already told you, you will have seen that there must be a close connection between the causes of volcanoes, earthquakes, and hot springs, (if they are not all to be ascribed to one cause,) from their always occurring in the neighbourhood of each other. But there is something else that you ought to notice in reference to this connection.
I said, that a volcanic eruption was almost always preceded by shakings of the ground round the root of the mountain. These shakings are sometimes so violent as to be dreadful earthquakes, and at other times the earthquake will be at a long distance from the volcano.
There was once a great earthquake which kept on for some days on the north shore of South America, and then stopped quite suddenly. It was afterwards found out, that just at the moment it stopped, a tremendous eruption burst forth from a volcano in one of the West-India islands, more than 150 miles off.
You know what the safety-valve of a steam-engine is. Now it would seem just as if volcanoes were safety-valves for the power which causes earthquakes.
Very well.—I am now going to tell you what people have thought this power has been owing to. Before I do so, that you may not be disappointed, I should tell you that we know very little on the subject; nor shall we ever know much till somebody can get down to the centre of the earth, unless some of the little black spirits, that the Rosicrucians called Gnomes, and fabled to live in the middle of the globe, should be kind enough to give us some information on the subject.
In the meantime, we can only guess; but we ought to guess as well as we can, and see whether our guess is not much more likely to be true than any of the others.
Volcanic bands are always near the sea-shore, and it has therefore been generally supposed that water has something to do with their action.