A radar rainfall area integrator is designed so as to indicate total precipitation amounts directly from the radar echoes over one selected watershed. The errors due to attenuation by range and intervening rain are corrected by an analogue computer.
An experimental anemometer with three semi-circular cylindrical shells with open ends is tested, in wind tunnel of its rotational speed in tilted attitudes. This is to clarify the proposal of I. FUJIMURA to install such type at mountain stations to be free from strong up-wash effect of wind often encountered. The results are disappointing and the standard three-cup anemometer is found to give rather constant rotational speed despite of up-wash or down-wash.
Ice crystals in the air    (Diamond dust) are formed in the lower atmosphere. In this report we explain the atmospheric conditions under which ice crystals are formed, first from data by radio-sonde and second from weather charts.
In order to examine the atmospheric contamination, we observed the concentration of sulphur dioxide. From January 18th,1955, through the 24th, we observed 5 times per day at 7 localities in Tokyo Prefecture. In the following pages the result of our observation and its relation to meteorological elements will be given a concise description.
At about midnight of 18th September,1954, a typhoon (No.14,1954) ran away toward the sea after attacking Japan. In place of the typhoon a colder and less moist air flowed in from the north. Just at the time, a new activity of artificial origin was detected in rain water at Niigata and Hirosaki, both situated along the Japan Sea coast of the northern part of the Main Island. From 22nd to 24th of September, the activity increased rapidly, spreading over a wide area in Japan and finally an activity as strong as 0.3 × 10-6 curie/l was counted in rain water at Yamagata. At the beginning of November 1954, another new activity almost comparable to that in September visited again. The estimated dates of explosion were respectively 13th-16th September and 28th-30th October. As air trajectories at 700 mb and 500 mb extended from Siberia to Japan, it might be supposed that the explosion tests would have taken place somewhere in USSR. Presence of fission materials was confirmed. It is to be noted, S. KOYAMA at Niigata Univ. estimated the presence of Np-239 and U-237 in rain water precipitated on 24th September. In autumn 1954, the activity was stronger along the coast of the Japan Sea than that on the Pacific side. Since the middle of March 1955, the radioactivities which might be attributed to Nevada experiments were detected several times both in rain water and the air at Tokyo and other places.
A radiochemical analysis of sea water containing fission materials collected near Bikini Atoll in June,1954, was performed. The sea water was boiled with hydrochloric acid, iron and lanthanum salts (each 5 mg as Fe and La) were added to it. They were precipitated as hydroxide, which was dissolved in hydrochloric acid and ferric chloride was extracted with ethyl ether. The remaining solution was evaporated to dryness and the residue was dissolved in hydrochloric acid. Using the latter solution the group separation was done with cation exchanger resins. To the filtrate separated from hydroxide precipitate, ammonium oxalate was added to produce the oxalate of alkaline earths. Strontium was separated by the use of fuming nitric acid. Analytical result shows the presence of Y-91, Ce-141,144, Ru-103,106, Rh-106, Zr-95 (Nb-95) and Sr-89 in which the most part was fractions of Y and Ce.
It is of importance to study the behaviour of carbonic acid substances dissolved in natural water in order to know the chemical properties of the water. Acidity or alkalinity method has been generally used for this purpose for a long time. But this method often leads to erroneous results. The present auth or proposed that a better way is to determine first the amount of total carbonic acid, pH and temperature, and then to calculate theoretically the amount of H2CO3, HCO3- and CO3- using equilibrium constants between them. However, such a calculation is too laborious for every analyst, and therefore the author completed tables convenient for use containing calculated values of molar fractions of each carbonic acid substance for different temperature and pH in fresh water and sea water. In these tables, one can find any necessary values of molar fraction when the total amount of carbonic acid, temperature and pH of waters are given. By the use of this method, exact determination of the amount of each carbonic acid substance in water is made possible.
The coagulation process of bubbles in the foam layer of sea water was studied and the following results were obtained. 1) During the period when the coagulation process of bubbles is dominant, the process can fairly well be treated by analogy with that of colloidal particles (Section 2, ii, iii). 2) The maximum diameters of bubbles at various times were calculated by the formula previously derived by the present author, namely p(x)=ABx, where p(x) is the frequency of a bubble, x the square of its diameter, and A and B are constants (Section 3).
In the present paper some investigations were made on the variations of wave-height and wave-period and their relations with meteorological changes such as the passing of cyclones, typhoons, cold fronts, etc., based on the wave gauge records obtained at Hachijo Island. From these results some empirical diagrams were constructed, which are available for forecasting ocean waves. A comparison with SVERDRUp-MUNK'Sth eory was made. Besides, an investigation on the distribution of wave-height around Hachijo Island and the annual variations of wave-height and wave-period was also made.
In regard to the approximate calculation of the formulae of radiative equilibrium in a scattering atmosphere CHANDRASEKHAR ,  gave an extensive numerical table of the function including an exponential integral as an integrand. As some of the formulae of this author also include the same function, it will be convenient to modify the formulae using the same notation as CHANDRASEKHAR.