Peiping, June 14.
NE of Peiping's most distinguished citizens, though little known outside his own particular scientific circles, is Dr. W. Grabau, Chief Palacontologist to the National Geological Survey of China. Dr. W. Grabau who is 70 years of age took up this post 20 years ago and has resided here ever since, where he has been continuously engaged in his scientific work.
The result of his studies he has recently published in a book entitled "The Rhythm of the Ages" (Henri Vetch, Peiping), in which he expounds his modern pulsation theory of the formation of the earth's surface.
The following notes, being rougir extracts from a lecture given by the author, gives the gist of this fascinating subject Geology is concerned not only with the material of which our earth is composed and the phenomena which it presents, such as volcanoes, earthquakes, mountain-building and—destruction, and so forth, but also with the life of the earth and its development since the beginning of Palaeozoic time, several milliards of years before man appeared on the scene, The crust of the earth, consisting of lighter types of rock, such as is, represented by the familiar granite land gneiss, is intensely folded and contorted, the trend-lines of these ancient foldings being in certain denite relations to the land masses, These folds, many of which must have been of mountainous dimensions, are everywhere worn down into a relatively level surface, with only. here and there "some " pronounced, elevations rising above the surface.
If in imagination one restores the old folds that have been worn away. and then flatten them out into. unfolded layer, this would have a vastly greater extent than is shown by the combined areas of the continent today. We are probably not, assuming too much considering, that such a layer would stretch en tirely over the earth sphere. 7 crustal sphere is called the Sial-sphere—from the composition of its rocks: silica and alumina—and_ has. an average thickness of from 35 10 40 kin.
It rests upon, and is partly submerged in, a sphere of heavier rock which is called Sima—after its chief components. silica and magnesia. It has a thickness of about 1,200 kin, or. with the deeper Palasite layer, 2900 kin. At the centre is the sphere in which nickel (UD, iron (Fe) and other heavy metallic elements. pr dominate, and this forms the inno most. or' Nifessphere. The specific gravity at the surface is 2.75 which Increases more or less regularly Hat the centre of the earth Sial Crust Very "Thin"
It is important to remember that the Sial crust of our earth forms only an insignificant part of the earth sphere, Tis thickness today averages Tess than 25 miles as. against the radius of the earth of about 4,000 miles, or equal to a erust of 1 min. thickness on a globe with radius of 160 min. This reduces the Sial crust to. the approximate. thickness of match-box wood. Of this, again about six sevenths are immersed in the underlying Sima-layer, while only tone seventh projects freely above it, The primitive earth may thus be pictured as formed of a heavy central core, the Nife-sphere, including perhaps a deeply buried heart of gold; this is surrounded by the Sim sphere; and this again by. the Sial-sphere. Outside this highest rock sphere is the sphere of water, which, it the continents were flattened out to a continuous level surface, and it the amount of water were not sentially different from what it is today, would form a universal ocean or primitive Hydro-sphere, the great Primitive shoreless sea of the earth with an average depth of about 1.65, miles. And last of all, round the shell of water is the gaseous. shell or Atmo-sphere, which, however, probably differed from the air of today in containing much of the ea bon (in the form of carbon dioxide which is now locked up in vegetation and in the coal-beds of the earth. This primitive earth of many concentric shells turned on an axis which maintained throughout all time essen-Wally the inclination to the plane of its ecliptic that it holds today. for the concentration of the water; the other that the Pacific basin is the scar left when the moon was torn from the earth, There remains then, only the theory of the compression of the original crust into" isolated Jand-blocks, or into one hemisphere of land, which subsequently broke up into continents, which in their turn floated apart to their present posi-
Even more difficult is the question of how the original single land mass. which spread over the whole earth, was transformed into a hemisphere of compressed and crushed gneisses and schists. Creep and the effect of compression, due to shrinking or other causes, have been appealed to, but this is; hardly a satisfactory explanation. 'The earth could no more shrug SMself out of its outer rock-shell unaided, than could a man wriggle out of his closely buttoned coat, without assistance either of his own' or other hands. But, if some extratelluric force was needed to withdraw part of the earth's outer shell, must have been one that acted in a poleward direction.
Possible Chang tion of the Polestar, of of a'star A stellar body, occupying the posi-
a corresponding position at Pele, might be invoked ax the agent, provided such star" could, upprench within proper distance of the earth 10 xertsuielent attraction, "Then the Sat crust might be withdrawn from the opposite part, ever the: more resistant Sima, dnd become concentrated iimo'n polar hemisphere of land. this process the rocks would become Intensely" "folded, and. a" compressed and. changed Si) would Yer and, ar the Slatesphere ie much an fnaigni: fant part of the whole, without fentany dstucbing the boston Which the earth occupies im space This may be iMustrated by a simple experiment. "if one. covers globe with a closely iting cent of thin Sloth, Fepresenting the Sia} erst, and Swithirawe from. one half of the Bove into.a folded crust om the other Feitea dette pattern of folds would Fenilt, tomewiat. ike the folds 2 hlf-closed globular paper lantern, 1 these fatds ore compared" with the. "ascertained. trend lines "of "the fidest rocks "on earth, a certain Similarity" will be found. "Th ie'at present no mathematical oF tronomical proof thatthe proce out-Tined "was possible pity until some ther "satisfactory" explanation "has Been found to" account for all the Bhenomena, we may Use the "Polar Gontrot® theory as a working mypofrets, We have now an earth withahemlsphere of land "round one of the poles, probably the South Pole, and hemisphere of sea round the Worth Bole." The floor of the sea was the Eurlace of the relatively smooth mac Sphere, and. the surface of the land the folded and eroded Sials-phere. On {he later come into existence "the Jong extended continental toughs. or feotynelines depressions in the s0r-{ce parallel to the outer margin and great length, but amy from 100 10 00" miles: In wath,
Text read from the printed page and cleaned; old type leaves the occasional error.