The present paper treated the waves at the common boundary of tw superposed fluids of densities ρ, ρ', one above other, moving with velocities U, U', respectively, caused by the bottom configuration given by the next function,
|x|>a, y=0;|x|<a, y=-h+M(a²-x²)
where h the depth of lower fluid.
The profile of the boundary is of quite a different form according to
Δ+ξ+μ-ξμ>0 or<0,
where ξ=U²/gh, μ=U'²/gh', Δ=ρ'-ρ/ρ, h', the depth of the upper fluid, g the acceralation of gravity, and in the former case the boundary has a train of stationary waves behind the obstacle at the bottom, but in the latter only the forced deformation is caused, the maximum height of which lies just above the middle point of the obstacle. Moreover, in both cases the form of the disturbed boundary has the less resemblance to the bottom configuration, as the non-dimmensional quantity 2πμ√_??_becomes larger.

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The motion of the bay water caused by the timely-varying wind force is theoretically treated, and some results are checked by tidal records of Urakami (Wakayama Pref.) in 1941.
The following results are obtained by the theory: (1) The seiche is more likely to be developed by sudden stress variation, on the other hand the forced accumulation of water is caused by gradual variation. (2) By the wind of the same variat ion, when the length constant, the shallower the bay, the more like ly is the seiche developed, and when the depth constant, the bay of length de termined by √gh/2v, where √gh is the velocity of the long wave in the bay, and V the abruptness of wind variation, is most oscillated.

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In these papers the author intends to discuss the distribution of the flow and suspending sands caused by wind in a uniform channel, which means a simple model of the strict distributions in shallow seas using the strict expression of the viscosity coefficient. Problem is solved for the stationary case and the numerical values are given, too.

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The writers carried out some measurements of the relative motions of sea-ice to the surface sea-water due to wind in 10 miles off the coast by two methods: the one is a method by the current measuring drift-buoy and the other is that by the inclination of lead-line. And they ascertained that the velocity of the relative motion changed in moderate extents by the difference of roughness on the upper surface of ice, and obtained 1/20-1/180 (for wind velocity 4-10m/sec) as the ratio and 18°-32° as the clock-wise deflection angle of the direction of the motions measured. from the wind direction. They considered from the above-mentioned results that the chief cause of the relative motion may be the wind pressure upon the parts of ice above the sea level. As the observed velocity of the relative motions of ice to sea water attained to the same order with those of the ice-drifts that observed by many authorities in the past, the writers noticed the necessity of taking the effects of the relative motion of ice (that is, the effects of wind-pressure drift) into consideration in the theoretical study of the drift-ice as same as the effects of the drift current of sea-water. The theoretical study may be reported in the next papers.

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The slope of the thermocline in the Tsushima Strait was computed from the monthly observtions extending for about 16 years. The secular formula for the velocity of the currents in stratified layers on a rotating ocean, and various features of the variation were examined in relation to the meteorological and hydrocraphical conditions in the surrounding area.

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Through the culture experiments on a marine plankton diatom, Skeletonema costatum, the following phenomena were observed.
When diatom growth progresses in the culture media which prepared from sea water and enriched with nitrate or ammonium respectively, the value of titratable base increases in the former but decreases in the latter. quantitative determinations show that the changes of this chemical component to the opposite directions in both media are exactly proportional, with the same ratio, to the increased amount of diatom, in other words, to the amount of nitrogen consumed by diatom.
On the important meanings involved in these facts were discussed from the stand point of chemical oceanography.

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Many experiments were made on colorimetric tests in sea-water with “alkali tre, atiaent” and in mixed sea-water of a dilute water-glass solution of known silica content. It is concluded that to estimate the silica content of sea-water the sample must be stand for half a month since bottled, and to correct the salt effect the factor “1.25” should be used as WATTENBERG or ROBINSON showed.

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In the water of the Tama River about 80% of the silica (determined by gravimetry) are estimated by the colorimetry at tne upper stream, but above 100% of it can be estimated at the lower. The colorimetric estimated values after mixing the fresh water with the sea water dhow more than those calculated before-mixing when below 80% of the silica content in the fresh water is determined colorimetry, and show less than when above 100% of it is determined.

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