| OCR Text |
Show Crust' of the Earth. Hon. II. J. Strutt, F. R. 8., has gathered gath-ered rocks from all the world over, granites from Cornwall nd Rhodesia, basalt from Greenland, the Victoria Falls and Ireland, syenite from Norway, Nor-way, leucite from Mount Vesuvius, and has estimated as a result of prolonged pro-longed Investigations that not more than one-thirtieth ot the total volume oi tho 'earth is composed or rocks, found on tho surface. As a result of his deductions ho estimates es-timates that the depth ot the earth's rock crust is approximately 45 miles. ThtB deduction coincides to a certain degree with the calculations of Prof. Milne, the earthquake exp'ert, who has been Investigating to the same end by the observation of earthquake tremors and their speeds. Prof. Milne Concludes that at a depth of 30 miles below the earth's surface exist rocks whose physical properties are similar to those found on tho c::'3rlor. Mr. Strutt computes tho Internal heat ot the globe to be about 1,600 degrees centlgrado at about 45 miles below- the surface. Such a heat lndl-tates lndl-tates tho melting point oPlron, but it is considerably below the melting point of platinum, which Dr. Harker fixed at 1,710 degrees centigrade. |
