The daily Alaskan., 1913-01-17
THE EARTH CRUST
Its Density, It's Thickness and the
 Pressure It ExertS.
A BAR TO WORLD EXPLOSION.

Could Never Be Blown Co Frsgments'
 Some writers have accounted for the asteroids on the theory that they are the fragments of a world that from some unknown cause has been explod- cd in it's orbit Similarly. many have thought that perhaps at some distant time. when the seas shall have been drunk up Into the cracked and thick ened crust of the age sErunken earth and the volcanoes-tbose vents of the fiery luterlor-shall have become chos' ed and extinct. the pentup gases gener' ated from the descending moisture by the stIll great internal heat may ac- tuaIly explode the old earth like yerltable bombshell
 But that can never happen.
 In 1883 Krakatoa. a sleepy old vol cano on a small island ln the strait of Sunda. between Java and Sumatra, began to show marked signs of uneasi- ness Round the volcano the Quaking earth opened enormous Assures in the bottom of the sea, down which rushed Nlagaras Of water Then the Assures closed and confined the engulfcd flood in the hot suhterrauean depths The water was quickly converted Into steam. the steam Into diSSociated gases, without room for expansion, It exerted a pressure equal Co that of the strongest dynamite.
 The great chimney of Erak0toa. sealed since the memory of man, barred the normal path of escape, Higher and higher mounted the pres. sure under the buge mass Of the vol cano: then. of a sudden. came a blast that actually shook the earth. Never before tn historic time had there been such a shock. The whole top of the old mountain was blown Into the sky. The recor was distinctly felt clear through the terrestrial ball
 This great CataClysm has been cited as an indication of the power of the pentup forces that may some day dis rupt the earth Itself Let us examine the underlying principles that must guide us in passing judgment on the correctness of this theory.
 An explosive compound Is a combuSt lble combined mechanically or chem. iCally either with oxygen or with an oxidizinC substance that win burn with. out the help Of atmospheric oxygen
 Among the most powerful high ex. plosives are nitrogClaun and plcrlc acid. each Of which has a density more than one and half times that of water. The products Of their combus- ton are nearly an gaseous, whereas the products Of the combustion of ordinary black CunpOwder are less than half gaseous The larger part is the solid matter that makes the smoke
 The energy that a high explosive can exert depends on the volume of the gases liberated and the temperature to which the heat Of the explosion can raise them
 The exact temperature of the gases liberated by a high explosive at the in' stant of detonatOn Is not absolutely known. but may be approximately learned through chemical experiment Nor is the amount of pressure known with absolute certainty. It Is probable, however. that nitroglycerin. niuogels- un and picric acid, when detonated 10 a confined space, exert a pressure some where between SOO,OOO and 5OO,OOO nouDds tO thp square inch
 If we assume tGSt the earth crust nas a density i've times that of water and that it's average thickness is dtU miles, then It follows that it exerts a pressure of more than 5OOOOO pounds to the square inch: If the crust is a hundred miles thick, then the pressure is more than a million pounds to the square inch a pressure certainly great CT than the expansive force eNerted by the most powerful nigh explosive, Plainly. no quantity of high explosive detonated under the crust Of the earth would be able to lift it. and consequent. ly we know that no world of the size of the earth can ever explode from its own pentup Internal forces.
 If, then, DO high explosive force Is sufficient to blow up a world the size of the earth. how can worlds explode3 There is only one way in which the heavenly bodies can become possessed of sufficient energy actually to blow up. and that Is by collision.
 The stars are flying about In space with velocities that range all the way from five miles a second to 5OO miles l second.
 If two celestial orbs. travelling each at velocity of 200 miles a second, met In a head-on collision they would be fused and gasided by the impact and the heat generated would be sufficient to break up the matter of both into It's ultimate elements and to expand it into nebulous haze. This is the way in which science says that new suns, new uebulae and new stars are born.-Hud'