EXACT SHAPE OF EARTH

Nelson Evening Mail, Volume LXIII, 1 April 1929, Page 5

EXACT SHAPE OF EARTH

SUBMARINE EXPEDITION PROBLEM FOR SCIENTISTS ' Equipped with delicate instruments and having aboard eminent scientists skilled in their use and operation, the American submarine S2l has .set out on a mission which is expected to solve the old question "What is the shape of the earth? ' In this submerged laboratory the picked groups of scientific observers will watch carefully over the functioning of an apparatus which photographs the timed swing of a pendulum which determines the force of gravity and records thereby the precise contour of the ocean's floor. The personnel of the expedition includes the Yimous Dutch scientist, Dr F. A. Veiling Meinesz, professor of geodesy of the University of Utrecht, as chief, with Dr. Frederick E.' Wright, of the Carnegie Institution of Washington, and Dr. Elmer B. Collins, principal scientist of the Naval Hydrographic Office. In addition to the ingenious pendulum apparatus brought to this country by the Dutch scientist, the S2l is equipped with an improved sonic depthfinder and other instruments with which to record all observations made. Actual measurements of intensity of gravity to obtain outlines of the earth have 'been made in a few restricted tracts in continental areas, and, though they have included only a fraction of the earth's surface, from these have been drawn our idea of the size of the earth. Until the development of Dr. Meinesz s instruments, it has been impracticable to obtain such measurements at sea. Even his instruments cannot be used except on a submerged submarine, where the minimum motion from the sea is experienced. The ordinary ocean swell caused movements too great to be eliminated within the capability to any pendulum device so far designed, but in a ship submerged below the influence of wave action a sufficiently steady platform is assured for the successful operation of Dr. Meinesz's instrument. Thus the submarine is the sole agency known_ to science for accomplishing the investigation essential for" determining the contour of the earth under the sea. This is a problem that has intrigued astronomers." geologists, and other scientists since Eratosthenes, more than 2000 vcars ago, employed as data the gnomons of Alexandria and Syena and the stadia bet-.nen. Essential to the investigations is not only the submarine's power to submerge, but its ability to receive time signals by radio and to take soundings at" great depths by means of Hie sonic depth-finder. Through the records of this instrument an accurate profile of the ocean bed may be l made simultaneously with the measurement of gravity of (hat area. The region to be traversed is one of the most -Interesting of the earth from a geophysical and ecological standpoint, ff believed that the* islands of the West Tndies are comparatively young. ecologically sroakiug. The ocean waters surged over the places now occupied by IWe islands in the not-distant past.. What r-aused these uplifts of Hie islands and what caused the crent ocean deeps fi-vnt lie amnnrr them? These, are problems on which we have been able to speculate nnlv. for we lm.ve not had the fundamental data on <vhieh to b-id.l theories and to give logical explanations,