The tide in the David Taylor Model Basin

Tidal observations were made during one week in the half‐mile long David Taylor Model Basin. Harmonic constants have been derived from an analysis of this tide, which has an average range of about 0.002 inch. The discrepancy between the measured tide and the equilibrium tide is attributed to motion of the concrete basin brought about by movement of the Earth's crust. This periodic Earth movement can be separated into two parts: that due to the periodic tilting of the surface due to tidal loading near the coast, and that due to the Earth tide or deformation brought about directly by the tidal forces. The loading effect is somewhat greater than the Earth tide and is a maximum about 0.6 hr before the time of high tide on the nearby Atlantic coast. After eliminating the loading effect as nearly as possible, a value of 0.74 was obtained for the expression (1 + k − h), which is a measure of the response of the Earth to the tide‐producing forces and therefore an indication of the Earth's rigidity. This is found to come within the range of results most generally accepted from the work of others.