Show Crust of the Earth lion n J Stiiitt F R S has gathered gath-ered rocks from all the world over granites fiom Cornwall and Rhodesia basalt from Greenland the Victoria Falls and Ireland sjcnlte from Norway Nor-way louche from Mount Vesuvius and has estimated as a result of prolonged pro-longed investigations that not moro than one thlrtioth of the total volume of the earth Is composed or rocks I found oif Ihe surface ASa result of his deductions ho estimates es-timates that the depth of the earths rock crust is approximately 45 miles This deduction coincides to a certain degree with tho calculations of Prof Mimic the earthquake expert 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 ao miles below the earths surface exist rocks whose physical properties are similar to those found on the exterior Mr Strutt computes the internal heat of tho globe to be about 1500 degrees centigrade at about 45 miles below the surface Such a heat indicates indi-cates the melting point of Iron but It is considerably below the melting point of platinum which Dr Harker fixed at 1710 degrees centigrade I |