This is a supplementary note to my previous paper. Here is made a discussion concerning the depth, to which the disturbance of wind waves sensibly extend. In §2, the expressions for the maximum velocity, U, and the horizontal distance, Δ, within which the water moves on the bottom of shallow seas were obtained, viz. where H is the wave height, λ is the wave length of the wind waves, and d' is the depth of the sea. The values of were computed for various values of d' and λ. Some discussions were made on the actual values of H and λ which come into the above expressions. In §3, is discussed the relation between the grain size of sand particles and the erosion velocity. It was concluded that on stormy weathers easily erodable material such as fine sand, etc. at the depth of 10m or thereabouts can be sufficiently eroded by the disturbance of the wind waves, although we cannot determine the limit of depth to which the effect of wind waves extends for the present.
1. Silica'e: Diénert-Wandenbulcke's method has been studied. The presence of chloride up to about 20% Cl- causes no error where the tint becomes slightly yellowish, this is however easily Eeglected with a pale yellow glass filter. The small content of phosphate (0.1mg P3O5/l) and iron (1mg Fe/l) a so gives no influence for this analysis. 2. Nitrite: Griess-Romijin's powder reagent (α-naphtylamine lgr., sulphanilic acid 10gr. and tartaric acid 89 gr.) is especially well adapted to the analysis of the nitrite in water. NH4C1, NaCl, KNO3, Na2CO3, CaCl2, Na2NO4, Na2SiF6, KH2PO4, MgCl2 and small quantity of Fe+++ and Fe++ do not interfere with the analysis.
The contents of this paper are as follows:- (1) Momentum-subsidence in the eddying flow. (2) Cpμ=k. (3) Values of eddy viscosity, thermal conductivity, mixing length and surface angles. (4) Winds in the free air.
The sand flow through the wooden channel was investigated and found two modes of flow corresponding to the laminar and turbulent flow in hydrodynamics. The former is the flow as solid and the latter is the flow as liquid. There are a great number of examples which belong to the category of the dynamics of sand in natural phenomenon, say, land-slide, snow slip, skee and so on, but the literature is uttery wanting on this subject. Therefor it may be interest and important to study the dynamics of sand, so the author tried some experiments on the sand flow through the wooden channel for this purpose, and found following results. (1) The relation between the velocity and the inclination of the channel is not so simple as one may thought at first but it built up two ports A and B. The velocity inereases enormously for the slight increase of the inclination for A, while it is not so great for B. (2) The velocity of sand is proporsional to the, square root of the width of the channel for a given angle. (3) The experiment was carried out with various material and it was found following experimental formulæ where η is equal to tan θc, and θc is the angle which separates A and B as part. (4) This two parts of the curve are concluded to be due to the differences of the motion corresponding to laminar and turbulent motion in hydrodynamics after the studies with camera & eyes. (5) Some of the results of the experiments can be explained by the assumption of two kind of flow above mentioned.
In the present report, is given the result of the harmonic analysis of the tide at Yokohama. The data analysed consist of the record of the self registering tide gauge observed during 1928-1935, and the method of analysis is that of A. T. Doodson, published in “Phil. Trans. Roy. Soc. London, Ser. A. Vol. 227, 1928”. The harmonic constants of sixty components of tide thus determined were given in a table. In order to check accounts, the values of A0+(Hm+Hs+H'+H0) and A0-(Hm+Hs+H'+H0) in the usual notation were calculated, which gave 2.914m and 0.722m respectively, being in a good agreement with the observed values 2.913m and 0.714m respectively. Again, the value of (H1+H0)/(Hm+Hs) was computed, which gave 0.6259, being also in a good accordance in its magnitude with that of the other stations in this country.
Using Bamberg's universal theodolite, the diameter of the horizontal circle of whfch is 13 cm, the position and the vertical deflection at Misima Branch were observed. The result are The triangulation was perf rmed by the backward intersection, and the astronomical latitude was determined by observing the altitude of the polaris near its transit.
The amount of lunar influence on the atmospheric pressure has been calculated from the table and compared with the observed one in the case of the Muroto Typhoon. Satisfactory prediction for the path of the Typhoon from the lunar effect is not expected in this case at least.