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Show Sea Level. Sea level In the scientific sensS means theoretical mean or average from which elevations or repressions on the earth are calculated. The coast and geodetic survey, which Is government govern-ment authority op such subjects, says : "Mean sea level may be defined as the surface which would be assumed by the water of the oceans at rest If there were no action by the wind or by the tides due to the attraction of the moon and sun. The sea level surface is at all points at right angles to -a free-(wlnglng free-(wlnglng plummet." |