On the other side of Kongo-horst lies the plain of Settsu, which sinks into Osaka Bay on the west. The Yodo River drains Lake Biwa, and passing through both the plains of Yama shiro and Settsu, it discharges into Osaka Bay Lying at its mouth, Osaka was for centuries a commercial centre of Japan and at present it is a flourishing industrial city. It is the second largest city of Japan with its popula tion of over 1,380,000. Kobe has an excellent harbor on the shore of the bay and is the largest importing port, especially cotton, in the empire.
On the south of this framework of and depressions lies the large, peninsula of Kii. It is bounded by the Idzumi Range, whose highest point is Katsuragi-san (2,814 feet). Ki-no-kawa flows in the valley at the southern foot of this range. The peninsula is very mountainous. Especially on the eastern side of Kumano-gawa, a deep transversal valley, the range attains a considerable height in many peaks of the Omine Group (culminating point is 6,153 feet) and Odaiga-hara-san (5,527 feet). These mountains are nothing but an extension of the noted Akaishi Range. The range dips down into the Sea of Ise at the peninsula of Akumi; but, reappearing in Shima Peninsula on the opposite coast of the sea, it extends westward with an increasing magni tude and height. Several geological forma tions from an old crystalline schist to the Ter tiary are exposed in the successive zones from north to south. The continuity of this system may well be traced in the island of Shikoku through Kii Strait.
On the other hand, the palzozoic mountain lands of Tamba lie north of the Yamashiro and Settsu basins. They occupy an extensive area of older formation, like the Hida Plateau, but not so high and inaccessible. On the north of these mountainlands is the wide Bay of Wakasa, its coast indented with many small inlets. On this bay are Maidzura, a naval port, and also Amano-hashidate, noted for its beautiful scenery.
The western part of Honshu forms the large peninsula of Chugoku. It is almost en tirely mountainous with a few plains along the coast and rivers. The mountains, however, scarcely exceed 4,000 feet in height, with the few exceptions of some volcanoes, which form a volcanic chain through the northern half of this district. Dai-sen (6,157 feet), Sambe yama (4,025 feet) and Aono-yama are the most celebrated volcanoes. The earlier geological formation of Chugoku is disturbed by the eruption of granite and other igneous rocks, which are now widely exposed throughout this district. Rivers are generally short, and there are only a few noteworthy ones such as Go no-kawa running into the Sea of Japan. Higashi-no-Okawa, Nishi-no-Okawa, Kawabe Kawa and Ota-gawa flowing into the Inland Sea of Setouchi. The coastal lines on both sides of this district show great contrasts. Along the Sea of Japan the coast is very poor with bays and islands. There is one independent range, the Shinji, forming a peninsula of Shi mane, which is separated from the main land by the Lagoon Naka-no-umi, Lake Shinji and the low plain of Kidzuki. The south coast of Chugoku is quite different. It faces Setouchi on the Inland Sea. This peculiar sea is a
zone of depression having Chugoku on one side and Shikoku and Kyushu on the other. It is divided into several or seas by groups of thousands of islands which now remain as detached elevations in this depressed zone. On the east, Awaji, the tHorse-island separates the Osaka Bay from Harima-nada. Midzu chima-nada, Bingo-nada, Aki-nada and Suo nada lie to the west. They are generally very shallow and in most parts do not exceed 20 fathoms in depth. The only portions where great depths are found are the narrow passages at the outlets of the sea, where the bottom is acted upon most effectively by the erosion of tidal currents.
The coastal line of Chugoku is highly de veloped on the shore of Setouchi. Numerous inlets cut into the land, and there are many good harbors and anchorages. Among them the Bay of Hiroshima is one of the best, with the city of the same name on its shore, and Ujina, its harbor, which was the headquarters of transport ships in the recent wars. Not far from Upna, and on the coast of an arm of Aki-nada, is the naval port of Kure with its large docks and arsenal. Itsuku-shima or Miyajima, situated in Hiroshima Bay, is noted for its beautiful scenery.
Shikoku.— As a whole this great island is a single mountain group of southern Japan. It is separated from Chugoku by the Inland Sea, while a great depression forms the large Bay of Tosa on the south, bounded by the two promontories, Muroto and Sada (Ashizuri), pro jecting southward into the Pacific. Kii Strait on the east and Bungo Channel on the west, cut off Shikoku from ICH Peninsula and Kyushu Island. There is a great similarity between the mountain formations of Shikoku and the others. Shikoku Range, which extends east and west through the island, is a continuation of the mountains in Kfi Peninsula and Kyushu Islands. The greater part of the island is very mountainous, and there are several lofty peaks, such as Tsurugi-san (7,354 feet) and Ishidzuchi-san (6,878 feet). The northern part of Shikoku, from which the two great penin sulas of Takanawa and Sanuki project into the Inland Sea, is very similar in its geological and topographical features to the Chugoku and Setouchi islands. The peninsula of Sanuki is nothing but a recently elevated tract of the same sea. Many isolated granite mountains and hills, like islands, stand on the low plain. Among many rivers, Yoshino-gawa is most noted. In its upper course it flows eastward, forming a valley in the Shikoku Range, then cutting through the range it forms the famous gorge of Oboke and Koboke and turns again eastward parallel to the range, flowing through a wide plain until it empties into Kii Channel. Other noted mountain rivers are Shimanto gawa, Niyodo-gawa and Monobe-kawa, which flow into the Bay of Tosa. A peculiar develop ment of the coastal line on the western side of the island shows many elongated peninsulas and promontories, such as Sada-no-misaki. Awa no-naruto, situated in the narrow strait between Shikoku and Awaji is very remarkable on ac count of its terrible whirlpools, which are caused by tidal currents.