The rivers of the province belong to the basins of the Indian Ocean and the Java Sea respectively, the water-parting being formed by the western and eastern ends respectively of the northern and southern lines of mountain peaks.
In winter, for example, when the northern monsoon begins to blow, numbers of denizens of the Sea of Okhotsk swim southward to the more genial waters of north Japan; and in summer the Indian Ocean and the Malayan archipelago send to her southern coasts a crowd of emigrants which turn homeward again at the approach of winter.
The Polynemidae, which range from the Atlantic through the Indian Ocean to the Pacific, supply animals from which isinglass is prepared; one of them, the mango-fish, esteemed a great delicacy, inhabits the seas from the Bay of Bengal to Siam.
The district forms a narrow strip of land between the Indian Ocean and the mountains which separate it from the independent kingdom of Siam.
On the Ottoman conquest of Egypt in the 6th century Suez became a naval as well as a trading station, and here fleets were equipped which for a time disputed the mastery of the Indian Ocean with the Portuguese.
