The readings of reversing thermometers have been corrected by making one correction-graph for each thermometer. But, this procedure is so laborious that the author has tried to do it by the graph which is able to be used commonly for all thermometers. The graph is based on Hidaka's formula:
1) Protected thermometer
Nearly equal correction values will be given, when t changes under the condition that V₀+t has a same value for the thermometers with different values of V₀ and τ also changes equally with t in amount. Based on this result, a correction-graph consisting of three elements, V₀+t, t' and τ was made. It is shown as Fig. 2.
2) Unprotected thermometer
Using three elements, V₀+t, dt' and tω-τ, a correction-graph was made. It is shown as Fig. 3.

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During February and March 1962, drift bottles were released in groups of 120 in the north-central North Pacific Ocean along long. 175°W from the Aleutian Islands to lat. 41°N and along long. 155°W from the Alaska Peninsula to lat. 46°N, at each degree of latitude.
Eighty recoveries have been reported which range from the Bering Sea to as far south as northern California. Bottles released in area of dichothermal water, moved northward and westward around the Gulf of Alaska; those released south of this area but north of the Subarctic-Subtropic boundary at approximately lat. 42°N, drifted eastward to the Washington, Oregon, and California coasts. No recoveries have been reported from bottles released at lat. 41°N.
Future drift bottle studies are discouraged, but a line or lines of drifting, telemetry buoys is suggested.

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The investigation on the hydraulic strength of the mortar container and the corrosion resistance of the metal covering, with reference to the disposal of radioactive wastes into the sea have been described in the previous report.
As the sea water easily permeates into the concrete container in the conditions of high hydraulic pressure on the deep sea floor, it is feared that the water soluble radioactive wastes may leak out from the container by the action of the molecular diffusion and then may contaminate the surrounding sea water. In order to investigate the abovementioned problem, studies were carried out on the diffusion in the container wall made of mortar.“The results on diffusion in mortar” which are obtained from experiments using NaCl solution as a tracer at the first step, will be reported in this paper. The concentration of chloride ion was determined by the method of titration by silver nitrate according to F. MOHR. In the investigation, the authors define that “the diffusion coefficient in mortar” is the physical constant which is mainly attributed to two factors, namely, the diffusing energy of solution and the porosity of the mortar.
As for chloride ion, the diffusion coefficient in the mortar of standard proportion is about 1.4×10^-9 to 5.4×10^-9 (cm²/sec). Moreover, we obtained the following relationship between the diffusion coefficient (D) and the coefficient of permeability (P), i. e. D is equal to a×P^0.5, where a is 3.16×10^-5, when D and P are larger than 10^-9 (cm²/sec, cm/sec respectively), and we estimated that D is equal to P when both D and P are smaller than 10^-9 (cm²/sec, cm/sec respectively).
Considering only about the present results with respect to chloride ion, we could not neglect the contamination of sea water resulting from the diffusion in mortar. We, however, are continuously carrying out the similar studies on the diffusion making use of water-soluble radio-isotope as a tracer, for the purpose of getting more details about the diffusion in mortar.

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When a great number of containers for the disposal of radioactive wastes were discarded into the sea at depths below 2, 000m safty methods of disposal were investigated.
Containers of drum size and model mortar containers were thrown into the sea and the terminal velocity was calculated from the records of falling containers by means of an echo-sounder. From these data it was found that in case the container is thrown in its sidelong position at the beginning of throwning the terminal yelocity of the container is almost identical with the value calculated. Furthermore in the testing tank tests of throwning small cylindrical mortar containers are performed and the falling state and distribution of points, whereat containers reached on the floor, were observed.
In case of throwning containers into the sea crack load of the containers and shock load given to the containers when they reached on the sea floor were calculated by changing dimensions and contents and states of the sea floor respectively and the safty velocity, at which no crack forms in the containers at the instant, when the containers reached on the sea floor, was found by calculation.

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