Show r s Sea Level 1 Sea Sell level Jevel h in the scientific sen sensa means theoretical mean or average from w which elevations or depressions on the earth earth are calculated The coast end and geodetic survey urvey which is government government govern govern- ment a authority on such subjects says Means Mean be defined the tho sea a level may a as surface which would be assumed by byth th the water of the oceans at rest if there ther were no action by y the wind or by the tides due to the attraction of the moon end and sun The sea level surface is atall at nt nil ill points at at- right angles to a free swinging plummet I 1 |