Word: rocks
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...seemed as though history was being overdramatic. The skies were fulgurant. Detonations of thunder echoed hollowly and mysteriously through the corridors of St. Peter's. The question of infallibility was put to the Council and 535 voted placet; 2 voted non placet. The dissenters were the Bishop of Little Rock, Ark., and the Bishop of Ajaccio, Corsica (where the first Napoleon was born). The question was put again and 537 voted placet...
...mining and geological engineering, is to be one of the most active subjects presented for discussion and study at the meeting of the American Institute of Mining and Metallurgical Engineers in New York City early next February. All means of securing evidence concerning conditions existing in the solid rock ahead of actual exploration by operations are of course of vital interest to men in this field and geologists and others interested in the development of natural resources have steadily been working on the improvement of methods for estimating the nature of bodies concealed in the crust of the earth...
Irregularities in the earth, such as masses of rock of lower or higher density than the surrounding material, or of higher or lower electrical conductivity influence the natural physical fields of the earth or artificial physical fields that can be found on the ground in question. The normal fields can be calculated accurately, and by measuring the departures from the normal, evidence is secured that is of possible service in estimating the properties of the mass concealed in the earth that is responsible for the departures...
...body of sulphide ore, for example, generally has higher electrical conductivity than the surrounding rock. If an electric current is passed through the ground, the flow of electricity will tend to concentrate in the material which offers least resistance to its passage, and valuable evidence concerning the relative conductivity of the rocks that comprise the area can be gained by observing with suitable devices the distribution of current. A convergence of flow lines into a good conductor can be readily detected, and even the effects of better conducting material at considerable depth can often be estimated with a fair degree...
...most delicate measurements made by the new methods is in the investigation of irregularities in the gravitational field of the earth by means of the torsion balance. Masses of density different from the surrounding rock, tend to deflect the direction of gravity and the change, though almost infinitesimal, from the standpoint of ordinary human experience, is capable of measurement by observing the amount of rotation of a light beam appropriately weighted and suspended on a thin platinum wire. Ore bodies themselves are rarely large enough to cause detectable variations in gravity, but large features such as heavier rock in cores...