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II. On Periodic Disturbance of Level Arising front the Load of Neighbouring 
Oceanic Tides. 
By K. Terazawa, Ri-Gakushi of the Imperial University of Tokyo. 
Communicated by Sir Joseph Larmor, F.R.S. 
Received April 17,—Read June 1, 1916. 
I. Introductory. 
In liis important observations on the lunar deflection of gravity, Dr. O. Hecker 
has pointed out that the force acting on the pendulum at Potsdam is a larger 
fraction of the moon’s force when it acts towards the east or west than when it 
acts towards the north or south. Various explanations of this anomaly have been 
proposed ; among them one, suggested by Prof. A. E. H. Love,* is that a possible 
cause may perhaps be found in the attraction of the tide wave in the North Atlantic. 
Recently Prof. A. A. Miohelson'I has found a similar result in his arduous task, 
successfully achieved, of obtaining a continuous record of the lunar perturbation of 
a very long water-level at Chicago. Prof. Sir J. Larmor kindly suggested to me 
a query, whether the excess-pressure of the tide in the North Atlantic would affect 
much the measurement of water-level at Chicago, owing to the elastic depression of 
the earth’s surface that it would produce. 
In the present paper the calculation is undertaken in order to ascertain to what 
extent the consideration of tilting of the ground is important for the explanation 
of this geodynamical discrepancy, on the assumption that the earth consists of elastic 
matter of uniform density and of uniform invariable elastic constants, and that the 
North Atlantic may be represented roughly as a circular basin and that the tide in it 
is uniform or else elliptic. The curvature of the earth is neglected, which is, of course, 
admissible for a first estimation. 
II. General Formulae. 
The solution of the equation of equilibrium concerning an elastic body with plane 
boundary, otherwise extending to infinity, subject to certain boundary conditions, 
* ‘ Some Problems of Geodynamics,’ Cambridge (1911), p. 88. 
t ‘ The Astrophysical Journal,’ vol. 39 (1914), p. 105. 
VOL. CCXVII.— A 550. 
G 
[Published July 12, 1916. 
