Geography of Asia though the Middle East is a division of Asia. The demarcation between Asia and Africa is the isthmus of Suez and the Red Sea. The border with Europe starts with the coast of the eastern Mediterranean, even though Turkey in the Near East extends partly into the Aegean Islands and includes Istanbul on the European side of the Bosphorus. On the north the boundary between the continents of Asia and Europe is commonly regarded as running through the Dardanelles, the Sea of Marmara, the Bosporus, the Black Sea, the Caucasus Mountains, the Caspian Sea, the Ural River to its source,
Iron metallurgy in Africa 20th century in many parts of sub-Saharan Africa, whereas in Europe and most parts of Asia they were replaced by the blast furnace before most varieties of bloomeries could be recorded. W.W. Cline's compilation of eye-witness records of bloomery iron smelting over the past 250 years in Africa is invaluable, and has been supplemented by more recent ethnoarchaeological and archaeological studies. Furnaces used in the 19th and 20th centuries ranges from small bowl furnaces, dug down from the ground surface and powered by bellows, through bellows-powered shaft furnaces up to 1.5 m tall, to 6.5m natural-draft furnaces (i.e. furnaces designed