It happened that they had two great earthquakes in the north eastern part of Shanhsi Province in this century, but no such great earthquakes had occurred in that district throughout the Ming and Ch'ing period, 1368-1911. The two maps most clearly indicate the features of these earthquakes. These two earthquakes resemble each other. They are near to each other in their epicentres, most heavily damaged areas, dates, with their whole disturbed areas covering nearly the same region. Their magnitudes presumed to be just the same, MK=5.8, M=7.7. The longest radius of the earthquake A is 618km, and that of B 534km, but if the earthquakee at Nant'ung, Chiangsu Province, is to be identified with A, the former radius amounts to as much as 1026km.
Concerning to both earthquakes, destruction of buildings or city walls, spurts of water, cracks of earth, the dead and injured of men and beasts were seen everywhere within the circle of VI isoseismal. The most heavily damaged area of A was Lingch'iûhsien, where all the constructions were completely destroyed, the death-roll over 5200. As to B the detailed states of Yüanp'ingchên are uncertain, but the damages there are said to have been the severest. The total of death-roll in various places is conjectured no less than several thousands.
The first shock of A is recorded to have occurred about 3 a. m. 28 June, 1626, and that of B between 11 a. m. to 5 p. m. 22 November, 1683. The data about the foreshock cannot be found, but concerning the aftershocks, those of A continued until over one month after, while those of B are recorded to have ranged the period from a few months at least to several years at most.

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Though the phenomena of anomalous propagation of seismic waves are affected by the thickness of Mohorovicic (or surface) layer, yet the main cause seems to consist in the strain of the earth's crust. The amounts of deviation in P wave's travel-time obtained from many earthquakes show a peculiar distribution and the deviation state is moving in a definite direction. The writer named them as “phase currents”.
The earthquakes occur at such a place where the movement of phase current is discontinuous, and their scale is roughly in proportion to deviation area (positive sign) partaking in the outbreak of them.

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In the preceding paper, the author assumed the density distribution of the subterranean structure was the eq. (4) and he deduced the coefficient C_m from the boundary conditions, these were the gravity and the density both observed on the earth surface.
By this method, he showed the actual structure was reasonably explained by the gravity anomaly.
Consulting the eqs. (2) and (6), he now assumes the distribution of excess mass on the surface ρ_em and their compensated subterranean mass ρ_em. They are the eqs. (8) and (9).
He takes this model for that of isostasy and calculates some quantities which are shown in Table 1, and Fig. 1.
When the surface topography are represented by the eq. (17) and the density on the surface is ρ_o, the isostatic anomaly is the eq. (28) in his model of isostasy.
These results are agreed with that of the Tsuboi's model which is identically independent from this model.
The relation between the isostatic anomaly and the coefficient of the rate of change of density λ is shown by the eq. (29).

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Various features on the temperature of the earth's interior were derived from the modern theory of solids. The main results are as follows: (1) Grüneisen's parameter in the R-layer (33-413km.) must be greater than 1.5. (2) Temperature in the D-layer (1000-2898km.) increases linearly with increasing depth and its gradient depends on the mean atomic weight rather than Grüneisen's parameter, for instance, 1.79°/km, for A=20 and 3.73°/km. for A=40. (3) Temperature gradient in the R-layer decreases with increasing depth.

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