The author has given following characters for the national parks in Japan, such as (1) characteristic, splendid beautiful sights in every season, (2) sanitary environment, (3) abundance of scenic spots and rich in historic association. The National Parks of the Seto Inland Sea and Ise-Shima are given an example of a sea park which are unparalleled in other countries, Each National Park of Fuji-Hakone, Daisen, Unzen, Kirishima and Daisetsusan occupies a volcanic area, and these, except the latter one, are excellent in the panoramic views of sea. The National Parks of Towada, Akan and Aso are noted by a grand caldera : especially the former two are characterized by lacustrine scenery. The scene of Yoshino-Kumano, Nikko and Japan Alps are grand.
In the old explosion crater of Yunotani, a parasite cone of Aso Volcano, there are many furnarols and hot springs such as Asogeyser, Hokojigoku, Shiraikejigoku, Suzumejigoku, Mochitsukijigoku, Bozujigoku, etc. These are grouped together forming Yuno tani Hot Spring. Regular variation of the chemical composition of water is pot recognized in Hokojigoku Geyser, while it is usually observed in many geysers during one cycle of the eruption. The mechanism of periodic eruption of the Hokojigoku geyser has been explained by the author's model experiments. We find many hot springs which contain strong radioactive gases in these three group of Yunotani Hot Spring.
In Italy, boric acid (H3 BO3) has been gathered from the subterranean water- vapour and also, electric power has been evolved from the source. Subterranean heat has not yet been studied and utilized in many volcanoes in Japan. Recently the author has examined its nature at Beppu, Oita Prefecture for the purpose in its utilization. A bore hole (3 inches in diameter) was drilled to the depth of 100 meters and water vapour erupted, Temperature of the vapour is 128°C at the top and 160 C at the bottom of the bore hole, and its yield is estimated to be 2, 000 kg/hr. The vapour consists almost wholly of 1120 (about 98.5% vol), and the amount of hydrogen sulphide (H2S), carbon dioxide (CO2) and other gases is limited to 1.5% vol. If we design electrification, we may presumably obtain 100KW. of electricity. The design of the electric power plant is proceeding and drilling of a bigger hole on the other hand is now under preparation.
Regarding the so-called Besshi-type bedded cupriferous pyrite deposits embraced in the crystalline schists in the South-West Japan ; the rule : “the shoot of the ore-body is in accord with the direction of he linear structure of the country rocks”, was advocated at first by Mr. Teiji Kamiyama in 1935. Assuming this rule as a whole, authors studied the 12th Takasuzu ore-body in Hitachi Mine (Besshi-type deposits), and then prospected the location of some part of the ore-body which had not yet been caught at the time. Finally a part of the ore-body was really caught at the location almost coincides with their expectations. Authors here present the report on the processes of reasoning of the prospecting as a practical example.