THE SHAPE OF THE EARTH.

Auckland Star, Volume XXX, Issue 88, 15 April 1899, Page 3 (Supplement)

THE SHAPE OF THE EARTH.

At a meeting of the Royal Geographical Society recently, a paper was read by Dr. J. W. Gregory, D.Sc, on 'The Plan of the Earth, and Its Causes,' in which it was stated that, despite the extreme variability in the shapes of the continents, and their apparently capricious? distribution, the arrangement of lana and water on the globe was based on a regular plan. The idea dates from the dawn of geographical science. The early classical geographers noticed how the seas radiated from the Levantine area, and opened to a broad boundless ocean. They accordingly described the land of the globe as an island, floating on a vast surrounding sea, whence channels converged towards the hub of. the classical universe. This radial plan reappears in the mediaeval 'wheel maps,' in which, Jerusalem being accepted as the centre of the world, the land areas were made to radiate from it like the spokes of a wheel. • The author reviewed the most recent and most brilliant work of his contemporaries, including M. Elie de Beaumont, in the science, and' concluded that the great geological earth movements exhibited a form of the earth's surface tetrahedral in form. Lowthian Green had assumed that the earth was a spheroid based on a regular geometrical figure. He adopted as his base the apparently hopeless and unsuitable figure of the tetrahedron, which is contained within four equal similar triangles. But it may be said that this tetrahedral theory is impossible, because we know that the earth is not tetrahedral,' but is an oblate spheroid of revolution. Recent discoveries, however, showed that the earth was not a true spheroid in any sense, being flattened at the Equator as well as at the Poles, and it was, therefore regarded as' an ellipsoid, with three unequal axes.' Nor is that allthere is good reason to believe that the earth is not even an ellipsoid, for the northern and southern hemispheres are unlike and the earth is, therefore, shaped like a badly made peg top. "Professor G. E. Darwin has even said that it more nearly resembles a potato than an orange. Moreover, there was evidence to show that the earth's figure was still more irregular than that of a pegtop, and that its shape had undergone a series of additional deformations. In conclusion, the author said that investigation had shown that, instead of the absolute fixity of the North Pole, it now shifts its position to an appreciable extent by the influence of the movements of the atmosphere, the unequal melting of the polar ice, and a heavy fall of snow on the Siberian highlands.