Morning journal and courier., 1884-08-19
WHY THE EARTH QUAKEs,
Forces That are Pent up Under tis and Would Smash us if They Got Loose.

Forces That are Pent up Under us and
 Would Smash us if They Got Loose.
 From the New York Sum-
 Professor George H. Merriman, of Rutgers college, New Brunswick, has made the crust of the earth study, and has written on the subject. He said yesterday:
 "While facts enough regarding the extent of the earthquake of Sunday have not come to hand to enable me to speak on the direc- tion of the earth wave or it's peculiar features as compared with other earthquakes, yet something may be said as to the latest con- victions of students of science on the nature of the earth below the point any man can penetrate. That may lead us to guess intel ligently at the cause of earthquakes.
 ''You know the long received theory of the nature of the interior of the earth was that it is molten mass, and that we move around on crust enveloping the earth and caused by the cooling off of this mass on the out side It is undoubtedly true that about thir- ty miles below the earth's surface the tenn perature is so high that everything is in a melted condition. We know this because we have learned that every fifty feet we pene- trate in the earth there is an increase in tenn perature of about one degree, and at a dis tance of thirty miles the heat is so great that lG, haps the melted mass is in the form of a li- quid. That would be certain but for the i'm mense pressure on it. The pressure is esti- mated at ten thousand tons on a square foot. Of course scientific men cannot experiment. with matter at high temperature with a pressure of ten thousand tons to a square foot, so we can only guess what may be it's condition. In talking about this melted mass thirty miles under us the term water substance is used by geologists.
 "How great is the distance through this water substance we do not know, but it is certain that it's density increases more and more, gradually, until the interior of the earth is solid, probably, from the ineonceiva- ble pressure one, two or three thousand miles from the surface. Sir William Thompson has demonstrated that the earth must have a core much denser than the land and water we live on. He points out the fact that if 8 shell only thirty miles thick surrounded 8 molten liquid mass, extending from one side of the earth through the center to the other side, then the moon, through the law of gray itation, would displace the liquid or gas in the interior of the earth to such an extent that the earth's crust would bulge out in the direction of the moon, making tide in the solid crust of the earth, as certainly as the skin of an orange bulges out when you squeeze the fruit between the palms of your hands And this would be evident to us be- cause the ocean tides would be almost, if not quite, imperceptib1e to us. To withstand the attraction of the moon, the earth, Sir William says, must be as rigid as steel.
 'tSo we have the theory that the crust of the earth floats on and imposes an immense weight on water substance, which is incon- ceivably hot. Now, as to the way an earth quake may be caused. Suppose moisture trickled gradually year after year through this crust into the heated mass. In our at mosphere steam would be produced. Thirty miles below us the pressure is so great that 1t is not likely that steam could be generated. One thing, though; the pressure of ten thou sand tons to the square foot, 8 pressure ex- erted in every direction, would be increased. Some effect must be produced down there, and it is easy to see that if one place in the earth's crust is weaker than another near the region where the water triekled in, then the weakest place must stan the strain It is not unreasonable to suppose that this pres sure below might be so great that the earth's covering was shifted little to adapt itself to the pressure from below This shifting of the crust is in fact the earthquake.
 "I believe this theory has the greater req