This article deals with the reasons why we recommend to the Government that electrification of the Government Railroads should be carried out as quickly as possible under the present situations. Most important reasons for the necessity of railroad electrification are the characteristics of energy-construction in Japan and the fact that the thermal efficiency of the steam locomotives is the lowest among the big consumers of coal in Japan. Hereupon the electrification will enable us to promote the economic rehabilitation as the result of the improvement of energy-construction in Japan.
Mean velocity of the river flow is proportional to the depth of the water and the slope of the water surface. It is said that the velocity is greater at the upper course with steeper slope than at the lower course with gentler slope in the normal i.w water level. In case of the good of the river Kitakami in 1948, however, the author examined the velocity of the transmission of the flood wave, finding that it is slower at the steeper slope in mountains and canyons than that of the lower flood plains. The reason for the decrease of the velocity in the flood flow in mountains has been explained as the result of the increase in the content of gravels and sands in the flood water.
The Yakeyama volcano is accessible from Kajiyashiki, a small town along the Hokuriku main line, passing through Otozaka and Yunokochi. It is about 16 kilo-meters from Yunokochi to the summit. The volcano is an isolated cone, rising up to 2, 400.3 meters above the sea-level. It is underlain by Tertiary sediments assigned to the Miocene and Pliocene. These formations are mainly composed of shale and sandstone with thin layers of limestone, being intruded by liparite, propylite, etc. They are well bedded and highly cuffed along the Yake-kawa and Ogura-gawa. Recent fluviatile deposits mostly accumulate along the Haya-kawa, and talus deposits rest upon the steep slope of the volcano. Mt. Yake is a Massive volcano built up of lava and agglomeratic lava partly covered by talus deposits and mud flow. These two kinds of lava are similarly represented by olivine-hornblende-bearing two pyroxene andesite containing the small fragments of liparite and basaltic rock. The mud flow begins to be exposed on the northern flank, from where it is traceable about 12 kilometers down to Otozaka along the Yake-gawa, Ogura-gawa, and Haya-kawa. It is characterized by the abundance of andesite blocks petrographically similar to the lava mentioned above in association with angular pieces of base rocks. The volcano has three explosion crater and many fumaroles. One of these-explosion craters is found on the summit and seems to have been formed in 1361. Other craters are situated on the northwestern flank just above Jigokudani and also at the northern foot close to the upper end, of Sainokawara. The former is said to have been exploded in 1852, whereas the latter is of unknown age and the mud flow is supposed to have poured out from here. Fumaroles were mostly opened in the recent explosion which suddenly took place on the fifth of February in 1949 after a long interval of quiescence elapsed since 1854.. Several fissures, on which these fumaroles were formed, are traceable from northeast to southwest on the summit (No. 1) and northeastern flank (No. 2-No. 7). Such fumaroles are bowl-like pits on the slope covered by talus deposits, but pass into irregular crevasses when the lava is exposed. The smoke is almost composed of steam with a small amount of H2S and SO4. Its temperature is 90, 2°-94, 5°C at the mouth of fumaroles.The surface close to smoking pits and crevasses is thinly veiled with sulphur and halotrichite. The seismological investigation carried out by Dr. Minakami, suggests that the source of this activity is probably situated three kilometers below the surface.
It is one of the most important pokicies, at present, to make direct connection with the resourceful Hokkaido and main land (Honshu) in order to promote its exploitation. As the route of the railway tunnel, we can lay out two routes ; one crosses the channel at its eastern cape of the Aomori Bay and the other at its western. The length of the each tunnel under the sea water is about 20 km., and the maximum depth of the water on the fatter route is about 80 m., shallower than the former. However all other conditions of the western route being favorable, we have been engaging in the investigations of the western route. The tunnel has the steepest grade of 12.51/000 and is 38, km. long. To drive the tunnel, the ordinary system (mountain-tunnelling method) must be adopted because of the reason that the minimum depth of the water (about 160 m.) exceeds far the limit (about 40 m.) of pneumatic method. So, in order to avoid the leakage, the tunnel must pass through safety-zone in a considerable depth from the sea bottom. The Tertiary tuff is most desirable for its watertightness and easiness of tunnel-driving. The geological factors, the rock-properties (hardness and permeability), spouting water, fault and collapse etc. must be seriously, taken in consideration for the construction work. According to the plan, the geological survey, boring work and seismic prospecting have been carried on from 1946 to the present. At Honshu side, seismic prospectings and the boring work (400 m.) were finished. But the boring work at Hokkaido side is now on half-way (132 m/200 m), and its remained Work and also the seismic prospecting on land and its subsidiary are intended to be carried out in 1949. It is proved at present so far as investigated that Tertiary system composed of volcanic products (mainly tuff-breccia) develops largely at both of the subsidiary of Honshu and Hokkaido capes, and also under the sea bottom.
Tidal current in a, narrow strait can be inferred from the tides at both ends of the strait. That is, if h be the difference of height of S ea surface at both ends, the velocity of tidal current, v, at a point within the strait is expressed by the formula ν=c√2gh where c is a constant such that o<c<l, and g is the acceleration due to gravity. And the turn of the current or the slack water lags behind the time of h becoming zero by some quantity peculiar to the point. In the present paper, the characteristics of the tidal current in the Simonoseki Straits were described, and prediction was made for the tidal current at a point in the middle part of the strait by the above method, which showed a good agreement with actual observations.
An allotment of irrigation water is the important problem which forms the foundation of Japanese rice-crop. In general, water supply is put in order according to the dimensions of rice field. But water share is given to an individual person in the special case, in which the difference in stage of development is pointed out as follows : Example (1) “Tazu” (owners of rice-field) system in Awazi Is. Hyogo prefecture. The investor, who has installed the irrigation equipments at the time of exploitation accommodates tenant with the right of using water and accepts rent, issuing water-share certificate which resembles to the registered certificate of shares. Example (2) “Ban-sui-kabu” (alternative water-supply certificate) in Sado Is. Niigata prefecture. The right of using water was divided into twenty-five according to the number of a farmer 350 years ago. The right has been sold off among the inhabitants owing.to both increase of houses and transfer of landownership. At present, only the possessor of the certificate can conduct water on droughty occasion. Example (3) The water concession in Kami-Ueno village, Kyoto prefecture. The right has been allotted to the farm house which exists in the village, There is no limit to the number of water-sh re certificate. Accordingly we have never heard the fact that the right were sold off or transferred.